U.S. patent application number 13/127284 was filed with the patent office on 2012-01-12 for unique dual-action therapeutics.
Invention is credited to Karine Fabio, Christophe Guillon, Diane Heck, Ned Heindel, Mou-Tuan Huan, C. Jeffrey Lacey, Jeffrey Laskin, Pramod Mohanta, Sherri Young.
Application Number | 20120010168 13/127284 |
Document ID | / |
Family ID | 42129175 |
Filed Date | 2012-01-12 |
United States Patent
Application |
20120010168 |
Kind Code |
A1 |
Laskin; Jeffrey ; et
al. |
January 12, 2012 |
Unique Dual-Action Therapeutics
Abstract
A new family of therapeutics which provides a controlled-release
delivery platform for non-steroidal anti-inflammatory agents on an
ester or an ester-carbonate backbone is disclosed herein. These
agents are reversible inhibitors of acetylcholinesterase and are
thus useful for clinical conditions benefiting from inflammation
suppression and cholinergic intervention. These compounds are of
the general formula wherein n=0, 1; X.dbd.C, Si, and N+ and
NSAID=ibuprofen, naproxen, indomethacin and diclofenac. Other
embodiments are also disclosed. ##STR00001##
Inventors: |
Laskin; Jeffrey;
(Piscataway, NJ) ; Heck; Diane; (Rumson, NJ)
; Huan; Mou-Tuan; (Piscataway, NJ) ; Fabio;
Karine; (Bethlehem, PA) ; Lacey; C. Jeffrey;
(Bethlehem, PA) ; Young; Sherri; (Bethlehem,
PA) ; Mohanta; Pramod; (Bethlehem, PA) ;
Guillon; Christophe; (Bethlehem, PA) ; Heindel;
Ned; (Easton, PA) |
Family ID: |
42129175 |
Appl. No.: |
13/127284 |
Filed: |
November 3, 2009 |
PCT Filed: |
November 3, 2009 |
PCT NO: |
PCT/US09/05971 |
371 Date: |
September 23, 2011 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61198147 |
Nov 3, 2008 |
|
|
|
Current U.S.
Class: |
514/63 ; 514/419;
514/512; 548/406; 548/500; 548/501; 556/418; 558/273 |
Current CPC
Class: |
A61K 31/196 20130101;
A61K 47/55 20170801; C07D 209/28 20130101; A61K 9/0014 20130101;
A61K 31/192 20130101; C07C 2602/10 20170501; A61P 29/00 20180101;
C07F 7/081 20130101; C07C 69/96 20130101; C07F 7/0812 20130101;
A61K 31/19 20130101; C07C 229/42 20130101; A61K 31/405 20130101;
A61K 47/54 20170801 |
Class at
Publication: |
514/63 ; 556/418;
558/273; 514/512; 548/406; 548/500; 548/501; 514/419 |
International
Class: |
A61K 31/695 20060101
A61K031/695; C07C 69/96 20060101 C07C069/96; A61P 29/00 20060101
A61P029/00; C07D 209/26 20060101 C07D209/26; A61K 31/404 20060101
A61K031/404; C07F 7/10 20060101 C07F007/10; A61K 31/265 20060101
A61K031/265 |
Claims
1. A compound of Formula 1 ##STR00050## wherein n is 0 or 1; X is
Si, C, or N.sup.+; wherein when X is C or N.sup.+, each R is alike
or different and is hydrogen or (C.sub.1-C.sub.6) alkyl; when X is
Si, each R is methyl; and NSAID is a non-steroidal
anti-inflammatory agent.
2. The compound of claim 1 wherein the NSAID is ibuprofen,
naproxen, indomethacin, diclofenac.
3. The compound of claim 1 which is
4-[{2-(4-isobutylphenyl)propanoyloxy}methyl]phenyl
3,3-dimethylbutyl carbonate,
4-[{2-(4-isobutylphenyl)propanoyloxy}methyl]phenyl
2-(trimethylsilyl)ethyl carbonate,
4-[{2-(2-Methoxynaphthalen-6-yl)propanoyloxy}methyl]phenyl
3,3-dimethylbutyl carbonate,
4-[{2-(2-Methoxynaphthalen-6-yl)propanoyloxy}methyl]phenyl
2-(trimethylsilyl)ethyl carbonate,
4-[{2-(2-Methoxynaphthalen-6-yl)propanoyloxy}methyl]phenyl
3-methylbutyl carbonate,
4-[[2-{1-(4'-Chlorobenzoyl)-2-methyl-5-methoxy-1H-indol-3-yl}ethanoyl]-me-
thyl]phenyl 3,3-dimethylbutyl carbonate,
4-[[2-{1-(4'-chlorobenzoyl)-2-methyl-5-methoxy-1H-indol-3-yl}ethanoyl]-me-
thyl]phenyl 2-(trimethylsilyl)ethyl carbonate,
[o-(2,6-dichloroanilino)phenyl]acetyl 3,3-dimethylbutyl carbonate,
[o-(2,6-dichloroanilino)phenyl]acetyl 2-(trimethylsilyl)ethyl
carbonate, 4-[{2-(4-isobutylphenyl)propanoyloxy}methyl]phenyl
2-(trimethylammonium)ethyl carbonate iodide,
4-[{2-(2-methoxynaphthalen-6-yl)propanoyloxy}methyl]phenyl
2-(trimethylsilyl)ethyl carbonate,
4-[{2-(2,6-dichlorophenylamino)phenylethanoyl}methyl]phenyl
2-(trimethylsilyl)ethyl carbonate, 3,3-dimethylbutyl
2-(1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl)acetate,
(S)-3,3-dimethylbutyl 2-(6-methoxynaphthalen-2-yl)propanoate,
3,3-dimethylbutyl 2-(2-(2,6-dichlorophenylamino)phenyl)acetate,
3,3-dimethylbutyl 2-(4-isobutylphenyl)propanoate,
2-(trimethylsilyl)ethyl
2-(1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl)acetate,
2-(trimethylsilyl)ethyl
2-(2-(2,6-dichlorophenylamino)phenyl)acetate,
(S)-2-(trimethylsilyl)ethyl 2-(6-methoxynaphthalen-2-yl)propanoate,
2-(trimethylsilyl)ethyl 2-(4-isobutylphenyl)propanoate,
2-[[2-[1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl]acetyl]oxy]-N-
,N,N-trimethyl-ethanaminium iodide,
2-[2-(6-methoxy-2-naphthalenyl)-1-oxopropoxy]-N,N,N-trimethyl-ethanaminiu-
m iodide, or
N,N,N-Trimethyl-2-[2-[4-(2-methylpropyl)phenyl]-1-oxopropoxy]-ethanaminiu-
m iodide.
4. A process identified herein as Method A for production of
compound of claim 1 wherein n is 1 and X is Si or C comprising the
coupling of the acid chloride of an ##STR00051## NSAID
[NSAID-CO--Cl] to the carbonate of a 4-hydroxybenzyl phenol
exemplified by 5 or 6 wherein these referenced carbonates were
prepared for this purpose by linking the requisite chloroformate to
4-hydroxybenzaldehyde with subsequent formyl reduction.
5. A. process identified herein as Method B for the production of
the compound of claim 1 wherein n is 1, X is Si or C comprising the
direct coupling of the NSAID's ##STR00052## carboxylic acid moiety
onto the benzyl alcohol carbonates (e.g. 5 or 6) by in situ
activation of that --COOH by carbonyldiimidazole or carbodimides
thus avoiding the intermediacy of an acid chloride.
6. A process identified herein as Method C for production of the
compound of claim 1 wherein n is 1, X is Si or C comprising the
direct coupling of the requisite NSAID carboxylic acid under
Mitsunobu conditions to the --CH.sub.2OH of p-hydroxymethylphenol
(4-hydroxybenzyl alcohol) and then reacting a chloroformate with
the phenolic hydroxyl of the resulting adduct.
7. A process identified herein as Method D for production of the
compound of claim 1 wherein n is 1, X is Si or C comprising the
displacement of the chloro from
Cl--CH.sub.2--C.sub.6H.sub.4--O--CO--O--CH.sub.2CH.sub.2--SiMe.sub.3
by the carboxylic acid anion of an NSAID carboxylic acid generated
in situ by a strong base in a non-polar, aprotic solvent
8. A process identified herein as Method E for production of the
compound of claim 1 wherein n is 0, X is Si or C by the
EDC-catalyzed, 4-(dimethylamino)pyridine-activated esterification
of either 3,3-dimethyl-1-butanol on 2-(trimethylsilyl)ethanol with
requisite NSAID acids as specifically exemplified by compounds
19-26.
9. A process identified herein as Method F consisting of three
steps for the production of the compound of claim 1 wherein n is 0,
X is N.sup.+ in which an NSAID is precondensed with
2-chloro-1-methyl-pyridinium iodide and the intermediate thereof
intercepted by the lithium salt of N,N-dimethylaminoethanol and
subsequently methylated to yield choline esters of NSAIDs as
specifically exemplified by compounds 27-29.
10. A pharmaceutical composition comprising a compound of claim 1
in a pharmaceutically acceptable carrier.
11. The pharmaceutical composition of claim 10 wherein the
composition is suitable for administration as a tablet or pill for
oral administration, a solution or suspension for parental
administration or ointment for topical application
12. A method for treating a systemic or topical inflammatory or
pro-inflammatory condition which comprises administering to the
patient a pharmaceutically effective amount of the compound of
claim 1.
13. The method of claim 12 wherein the systemic or topical
inflammatory or pro-inflammatory condition is vesication, multiple
sclerosis, Alzheimer's disease, depression, amyotrophic lateral
sclerosis, dementia, Parkinson's disease, or other
neurodegenerative states
14. The method of claim 12 wherein the compound is administered
topically, parenterally or orally
15. The method of claim 12 wherein the compound is employed
prophylactically to prevent vesication or inflammation subsequently
to be effected by chemical agents known to produce such vesication
or inflammation.
Description
[0001] This invention relates to a new class of reversible
inhibitors of acetylcholinesterase (International Enzyme
classification EC3.1.1.7) which serve simultaneously as pro-drugs
capable of releasing non-steroidal anti-inflammatory agents
(NSAIDs) by hydrolysis at either one or two chemically different
hydrolytically-active loci.
BACKGROUND OF THE INVENTION
[0002] Inflammatory processes, often amenable to address by
non-steroidal anti-inflammatories such as ibuprofen, naproxen,
indomethacin and diclofenac, are inherent in the pathologies of
multiple sclerosis, Alzheimer's disease, depression, amyotrophic
lateral sclerosis, dementia, Parkinson's disease, and other
neurodegenerative states. Several of these diseases are also
independently characterized by perturbation of cholinergic balance
and hence therapies combining cholinesterase inhibitors and
inflammation mediators are believe to represent a dual benefit.
[0003] The chronic use of indomethacin and other NSAIDs either in
prophylaxis or in therapy risks adverse gastrointestinal effects,
renal toxicity, allergic responses, and occasionally severe
ulcerations. A highly lipophilic ester "pro-drug" of indomethacin
[DP-155] has been claimed to deliver enhanced brain levels while
markedly decreasing both renal and gastrointestinal toxicities (E.
Dvir, A. Elmann, D. Simmons, I. Shapiro, R. Duvdevani, A. Dahan, A.
Hoffman, and J. E. Friedman, CNS Drug Rev. 2007, 13: 260-277). The
pro-drug conjugate was efficacious in reducing levels of amyloid ss
(Ass) 42 in a transgenic Alzheimer's disease mouse (Tg2576). In
DP-155, a methylene chain spacer separated the indomethacin ester
from the ester at the lipid carrier terminus. For this purpose, a
five carbon spacer was shown to be 20-fold better in transmembrane
absorption than a short two-carbon spacer (A. Dahan, R. Duvdevani,
E. Dvir, A. Elmann, and A. Hoffman, J. Control Release 2007, 119:
86-93).
[0004] Orally-administered NSAID-esters of basic aminoalcohols are
reported to be competitive reversible inhibitors of AChE and to
reduce intestinal gastric ulceration often associated with the
non-conjugated NSAID carboxylic acids or their salts (P. K. Halen,
K. K. Chagti, R. Giridhar, and M. R. Yadav, Chem. Bio. Drug Des.
2007: 70: 450-455). The cholinergic anti-inflammatory pathway is a
high value therapeutic target readily justifying the combination of
anti-cholinergic and anti-inflammatory activity into a single
molecule. Wang has noted that binding at the acetylcholine receptor
is a down-regulatory mechanism for inflammation (H. Wang et al.,
Nature 2003, 421: 384-388).
[0005] Amitai has shown that the combination of an
anti-inflammatory (ibuprofen or diclofenac) and an inhibitor of
acetylcholinesterase into the same molecule provided a therapeutic
benefit in the treatment of inflammation resulting from chemical
blistering agents (A. Amitai, R. Adani, E. Fishbein et al., J.
Applied Tox., 2006, 26: 81-87). Although doubly functionalized with
an NSAID and an anti-cholinergic, in this case the two moieties
could not be independently liberated in vivo. Thus there remains a
need for additional moieties that can be independently liberated in
vivo.
[0006] This application relates to a unique lipophilic pro-drug of
an NSAID such as indomethacin (or other NSAIDs) which is
simultaneously a competitive reversible inhibitor of
acetylcholinesterase and a controlled release carrier of the NSAID.
These pharmaceuticals are unsymmetrical alkyl-aryl carbonates whose
--O--CO--O-- bond is readily cleaved both by chemical hydrolysis
and esterolytic activity, thereby freeing an NSAID by a facilitated
hydrolysis. Since the NSAID is directly attached to the platform by
a hydrolyzable ester function, there are two modes by which the
NSAID is made available.
[0007] Accordingly, one embodiment of the invention relates to a
compound of Formula 1 wherein
##STR00002##
wherein
[0008] n is 0 or 1;
[0009] X is Si, C, or N.sup.+;
[0010] wherein when X is C or N.sup.+, each R is alike or different
and is hydrogen or (C.sub.1-C.sub.6) alkyl;
[0011] when X is Si, each R is methyl; and
[0012] NSAID is a non-steroidal anti-inflammatory agent.
[0013] The invention is more fully described below in conjunction
with the figures wherein:
[0014] FIG. 1 shows a HPLC chromatogram obtained in chemical
hydrolysis of the compound of Example 9.
[0015] FIG. 2 shows a Lineweaver-Burk plot for reversible
inhibition of acetylcholinesterase in absence and in presence of
inhibitor Example 9 and 22 wherein the reciprocal of the velocity
.nu. (M min.sup.-1) is plotted against the reciprocal of the
substrate concentration s (.mu.M).
[0016] FIG. 3 shows a HPLC chromatogram of the hydrolysis of
Example 14 and release of parent NSAID after incubation in human
plasma.
[0017] The high level of esterase activity (arising from native
acetylcholinesterases, carboxyesterases, and related esterases)
found in human skin, epidermal membranes, and plasma, makes
ester-containing pro-drugs attractive targets as drug-delivery
vehicles for topical or oral formulations (J. L. Prusakiewicz, C.
Ackermann, and R. Voorman, Pharmaceutical Research 2006, 23:
1517-1524). Other studies have shown that a carbonate-linkage
(--O--CO--O--) is always very similar in behavior to an
ester-linkage as the hydrolysable function joining drug to carrier
(J. Rautio et al., Nature Reviews Drug Discovery 2008, 7: 255-270).
In a limited set of 17 analogs, Vaddi compared esters to carbonates
as pro-drug linkers to naltrexone and found the carbonates to have
a faster transdermal flux rate and to be slightly more resistant to
hydrolysis in the skin (enzymatic and hydrolytic) itself than was
the case with the esters. More esters were cleaved in the skin
leaving lower quantities available for penetration and transport in
the plasma. The differences in absorption rate and hydrolysis rate
between esters and carbonates were real but were not large (H. K.
Vaddi, et al. Pharmaceutical Research, 2005, 22: 758-765). As far
as purely chemical cleavage, most carbonates were less reactive to
hydrolysis in acid or in base than were esters (J. Ostergaard and
C. Larsen, Molecules, 2007, 12: 2396-2412).
[0018] The use of the construct p-(X-methyl)phenol (or an ester or
carbamate of it) as a platform for the release of two molecular
fragments in vivo--both of which in some cases possess biological
activity--has been applied by accident and by deliberate design in
several agricultural and pharmaceutical products. The principle
displayed here is that electron delocalization from the phenolic
oxygen provides an indirect cleavage pathway for an anionic species
(viz., p-X--CH.sub.2--C.sub.6H.sub.4--O--R if converted by cleavage
at R to p-X--CH.sub.2--C.sub.6H.sub.4--O.sup.- will liberate
X.sup.-). The presumed electron pathway is shown below. The attack
at R is usually a hydrolysis at a carbonyl.
##STR00003##
[0019] In the nitric oxide donating aspirin conjugate known as
NO-ASA, R in the structure shown above is aspirin (acetylsalicylic
acid) linked at its carboxylic moiety and X is the NO-precursor
--O--NO.sub.2. Promising results have been reported against colon,
pancreatic, and breast cancers as well as in protection of gastric
mucosal irritation and enhancement of in situ antioxidant events.
(J. L. Williams, P. Ji, N. Ouyang, X. Liu, B. Rigas, Carcinogenesis
2008, 29, 390-397 and S. Kwiecien, M. W. Pawlik, T. Brzozowski, et
al, J. Physiol Pharmacol. 2008 Suppl 2:103-15). The in vivo release
of thalidomide and nitric oxide from a conjugate drug in which R in
the structure above is the carbamate of thalidomide and X is the
NO-precursor --O--NO.sub.2 arrested the growth of malignant liver
cells (T. Wang, Y. H. Zhang, H. Ji, et al., Chinese Chemical
Letters, 2008, 19: 26-28). Immonium chlorides derived from DMF and
4-(chloromethyl)phenyl chloroformate (X in above formula=Cl,
R.dbd.CH.dbd.N.sup.+Me.sub.2) hydrolyzed to useful bactericides
presumably by the indicated mechanism but not recognized as such by
the authors (V. A. Pattison and R. L. K. Carr, U.S. Pat. No.
3,983,178). In a family of pro-pesticides which hydrolyzed to
potent acaricides by the general structure shown above,
R.dbd.--P(.dbd.O)OR/SR' and X.dbd.SCH.sub.3. (R. Sehring, W. Buck,
R. Prokic-Immel, S. Lust, Ger. Offen. DE 3223949, 1983 and W. Buck,
G. Geisthardt, R. Prokic-Immel, R. Sehring, Dokl.
Soobshch-Mezhdunar. Kongr. Zashch. Rast., 8.sup.th 1975, 3:
50-57).
[0020] As a general class, these substances--with n=0, 1 and
X.dbd.C, Si, and N.sup.+--can be described as:
##STR00004##
[0021] Variation in the alkyl function provides the recognition
moiety for the target enzyme with choline-like mimics such as
--CH.sub.2CH.sub.2T(Me).sub.3 [wherein T=N.sup.+, Si, or C]
providing the traditional molecular architecture required for site
affinity at acetylcholinesterase. Even though the structural shift
from a water-soluble trimethyl ammonium [.sup.+NMe.sub.3] to a
trimethyl carbon [--C(CH.sub.3).sub.3] or to a trimethyl silyl
[--Si(CH.sub.3).sub.3], means an increasing hydrophobicity, these
moieties can nevertheless by recognized and bound to
acetylcholinesterase. As Cohen phrased it in reference to the quat
silyls and quat carbons, . . . "the enzyme stands nearby ready to
bind and try to hydrolyze and remove compounds that even
superficially resemble the natural agonist." (S. G. Cohen, S. B.
Chishti, J. L. Elkind, H. Reese, and J. B. Cohen, J. Med. Chem.
1985, 28: 1309-1313). Variation of n=1 to n=0 allows the
incorporation or non-incorporation of a p-hydroxybenzyl alcohol
linker moiety whose presence increases the lipophilicity of the
final construct by 1.9 log units (c Log P, a computed quantity for
hydropholic/hydrophilic molecular property). In addition to adding
lipophilicity when desired, this linker (when present) provides two
sites of controlled hydrolytic/enzymatic release of the NSAID at a
carbonate and at an ester functionality.
DETAILED DESCRIPTION OF THE INVENTION
[0022] In an earlier study we disclosed a class of toxic
choline-chloromethyl aryl carbonate insecticides which were
"suicide-like substrate" inhibitors of acetylcholinesterase.
These
Cl--CH.sub.2--C.sub.6H.sub.4--O--CO--O--CH.sub.2CH.sub.2-T(CH.sub.3).sub-
.3 where T=N.sup.+ or C
compounds were--upon hydrolysis by the enzyme--covalently and
irreversibly linked to AChE. Recent pharmaceutical research,
however, has shown that irreversible "suicide inhibition," which
because of the covalent anchoring of the drug fragment generates a
now "foreign" protein, can trigger an autoimmune-response in the
patient (E. Fontana, P. M. Dansette, and S. M. Poli, Current Drug
Metabolism, 2005, 6: 413-454). Thus, too toxic and too
inappropriate for human therapeutic use, these substances
nevertheless proved useful in control of the tobacco budworm and
the southern corn rootworm [N. Heindel, M. Turizo, H. D. Burns, and
V. Balasubramanian, U.S. Pat. No. 5,082,964 (Jan. 21, 1992) and N.
J. Brenner, N. D. Heindel et al., "Arylcholine Carbonates and
Aryl-3,3-dimethyl-1-butyl Carbonates as Inhibitors and Inactivators
of Acetylcholinesterase," Chapter 37 in ACS Symposium #443,
Synthesis and Chemistry of Agrochemicals II, ACS Publishers,
Washington, D.C., 1991, pp. 469-477].
[0023] Amazingly, we have since discovered that when the leaving
group in the above mentioned carbonates is anything other than
chloro or bromo, these carbonates are no longer substrates for AChE
and they are no longer "suicide-like" irreversible
alkylator-inhibitors. Interestingly, Boyle has shown that simple
alkyl thiocarbonates of choline are partial competitive inhibitors
which are not hydrolyzed by the enzyme (N. A. J. Boyle et al., J.
Med. Chem. 1997, 40: 3009-3013). Relatively small changes in these
carbonate-choline mimics can have a major effect on activity. That
principle has led to the new family of NSAID-ester-carbonates
claimed herein as therapeutics for diseases and clinical conditions
benefiting from inflammation suppression and cholinergic
intervention because an NSAID can be released by two alternative
hydrolyses from a highly lipophilic carrier.
[0024] In practice, a composition containing a compound of Formula
1 may be administered in any variety of suitable forms, for
example, parenterally, rectally, or orally. More specific routes of
administration include intravenous, intramuscular, subcutaneous,
intraocular, intrasynovial, colonical, peritoneal, transepithelial
including transdermal, ophthalmic, sublingual, buccal, dermal,
ocular, nasal inhalation via insufflation, and aerosol.
[0025] A composition containing a compound of Formula 1 may be
presented in forms permitting administration by the most suitable
route. The invention also relates to administering compositions
containing a compound of Formula 1 which is suitable for use as a
medicament in a patient. These compositions may be prepared
according to the customary methods, using one or more
pharmaceutically acceptable adjuvants or excipients. The adjuvants
comprise, inter alia, diluents, sterile aqueous media and the
various non-toxic organic solvents. The compositions may be
presented in the form of oral dosage forms, or injectable
solutions, or suspensions.
[0026] The choice of vehicle and the compound of Formula 1 in the
vehicle are generally determined in accordance with the solubility
and chemical properties of the product, the particular mode of
administration and the provisions to be observed in pharmaceutical
practice. When aqueous suspensions are used they may contain
emulsifying agents or agents which facilitate suspension. Diluents
such as sucrose, ethanol, polyols such as polyethylene glycol,
propylene glycol and glycerol, and chloroform or mixtures thereof
may also be used. In addition, the compound of Formula 1 may be
incorporated into sustained-release preparations and
formulations.
[0027] For parenteral administration, emulsions, suspensions or
solutions of the compounds according to the invention in vegetable
oil, for example sesame oil, groundnut oil or olive oil, or
aqueous-organic solutions such as water and propylene glycol,
injectable organic esters such as ethyl oleate, as well as sterile
aqueous solutions of the pharmaceutically acceptable salts (when X
is N.sup.+), are used. The injectable forms must be fluid to the
extent that it can be easily syringed, and proper fluidity can be
maintained, for example, by the use of a coating such as lecithin,
by the maintenance of the required particle size, in the case of
dispersion and by the use of surfactants. Prolonged absorption of
the injectable compositions can be brought about by use of agents
delaying absorption, for example, aluminum monostearate and
gelatin. The solutions of the salts of the products according to
the invention are especially useful for administration by
intramuscular or subcutaneous injection. Solutions of the neutral
compound of Formula 1 wherein X is C or Si and pharmacologically
acceptable salts of the subgenus of Formula 1 wherein X is N.sup.+
can be prepared in water suitably mixed with a surfactant such as
hydroxypropyl-cellulose. Dispersion can also be prepared in
glycerol, liquid polyethylene glycols, and mixtures thereof and in
oils. The aqueous solutions, also comprising solutions of the salts
in pure distilled water, may be used for intravenous administration
with the proviso that their pH is suitably adjusted, that they are
judiciously buffered and rendered isotonic with a sufficient
quantity of glucose or sodium chloride and that they are sterilized
by heating, irradiation, microfiltration, and/or by various
antibacterial and antifungal agents, for example, parabens,
chlorobutanol, phenol, sorbic acid, thimerosal, and the like.
[0028] Sterile injectable solutions are prepared by incorporating
the compound of Formula 1 in the required amount in the appropriate
solvent with various of the other ingredients enumerated above, as
required, followed by filtered sterilization. Generally,
dispersions are prepared by incorporating the various sterilized
active ingredient into a sterile vehicle which contains the basic
dispersion medium and the required other ingredients from those
enumerated above. In the case of sterile powders for the
preparation of sterile injectable solutions, the preferred methods
of preparation are vacuum drying and the freeze drying technique,
which yield a powder of the active ingredient plus any additional
desired ingredient from previously sterile-filtered solution
thereof.
[0029] Topical administration, gels (water or alcohol based),
creams or ointments containing the compound of Formula 1 may be
used. The compound of Formula 1 may be also incorporated in a gel
or matrix base for application in a patch, which would allow a
controlled release of compound through transdermal barrier.
[0030] The percentage of compound of Formula 1 in the compositions
used in the present invention may be varied, it being necessary
that it should constitute a proportion such that a suitable dosage
shall be obtained. Obviously, several unit dosage forms may be
administered at about the same time. A dose employed may be
determined by a physician or qualified medical professional, and
depends upon the desired therapeutic effect, the route of
administration and the duration of the treatment, and the condition
of the patient. In the adult, the doses are generally from about
0.001 to about 50, preferably about 0.001 to about 5, mg/kg body
weight per day by inhalation, from about 0.01 to about 100,
preferably 0.1 to 70, more especially 0.5 to 10, mg/kg body weight
per day by oral administration, and from about 0.001 to about 10,
preferably 0.01 to 10, mg/kg body weight per day by intravenous
administration. In each particular case, the doses are determined
in accordance with the factors distinctive to the patient to be
treated, such as age, weight, general state of health and other
characteristics, which can influence the efficacy of the compound
according to the invention.
[0031] The compound of Formula 1 used in the invention may be
administered as frequently as necessary in order to obtain the
desired therapeutic effect. Some patients may respond rapidly to a
higher or lower dose and may find much weaker maintenance doses
adequate. For other patients, it may be necessary to have long-term
treatments at the rate of 1 to 4 doses per day, in accordance with
the physiological requirements of each particular patient.
Generally, the compound of Formula 1 may be administered 1 to 4
times per day. Of course, for other patients, it will be necessary
to prescribe not more than one or two doses per day.
[0032] Synthetic assembly of the NSAID-cholinergic conjugate was
achieved by four different experimental techniques. First, in
METHOD A, an acid chloride of the NSAID can be coupled to the
appropriate p-hydroxymethylphenyl carbonate. NSAIDs used in this
work were naproxen, ibuprofen, indomethacin, and diclofenac, but
the method is general to the release of any other carboxyl
terminated anti-inflammatory or other carboxyl-containing
pharmaceuticals. As a specific example, the coupling of ibuprofen
acid chloride to 4-(hydroxymethyl)phenyl 3,3-dimethylbutyl
carbonate is shown. Syntheses of the acid chlorides and the
4-(hydroxymethyl)phenyl carbonates as required in METHOD A is
described below.
##STR00005##
[0033] The compounds are administered to patients by means known in
the art including orally, parentally. The compounds of the
invention are formulated as liquids, suspensions, tablets as is
known in the art.
Example 1
Materials and Methods
[0034] All reactants and solvents were of the highest purity
commercial grade and were employed without further purification.
The suppliers of uncommon reactants are indicated for those
reactions and assays reported herein which employ a specialized
reagent. All reactions were performed in oven-dried apparatus.
.sup.1H NMR and .sup.13C NMR, spectra were recorded on a 500 MHz
(Bruker) multinuclear spectrometer and chemical shifts are reported
as ppm. All thin layer chromatography (TLC) was performed on
Analtech silica gel plates (250 microns). Elemental analyses were
performed at Quantitative Technologies (QTI), Inc. The
2-(2-methoxynaphthalene-6-yl)propanoic acid (naproxen) used in this
work was the (S)-enantiomer. All other reagents were used as
racemates.
Examples by METHOD A
[0035] By METHOD A, an NSAID converted to its acid chloride is
coupled to 4-hydroxybenzaldehyde, the aldehyde reduced to a benzyl
alcohol, and that alcohol condensed with an appropriate
chloroformate (which had been prepared in a separate synthetic
step) to give the objects of this invention, the final
carbonate-esters, in overall yields of 22-45% for this five-step
pathway. This variation of METHOD A is the Formyl Reduction
Pathway.
[0036] An abbreviated variation of METHOD A, the Direct Selective
Acylation Pathway, uses pH and temperature control to condense the
chloroformate specifically onto the phenolic --OH of
p-hydroxybenzyl alcohol. This variation avoids the use of
p-hydroxybenzaldehyde and shortens the synthesis by one step. This
boosts the overall yields to 35-55%. Both pathways are discussed
with specific examples below.
Preparation of the NSAID Acid Chlorides
Example 2
Preparation of 2-(4-Isobutylphenyl)propanoyl Chloride [ibuprofen
acid chloride]
##STR00006##
[0038] A silicone oil bath was heated to 130.degree. C. A reaction
set-up was prepared consisting of a 200 mL round bottom flask with
condenser and rubber septum-capped joints. After mixing the
reactants as described below, the flask and contents were placed in
the oil bath. Thionyl chloride (29.7 g, 0.25 mol) was added via
glass syringe to 2-(4-isobutylphenyl)propionic acid (10.3 g, 0.05
mol) in dry toluene (60 mL) at room temperature under nitrogen
atmosphere. The reaction mixture was then heated at 130.degree. C.
for 2.5 hr, removed from the oil bath, and allowed to cool to room
temperature. The condenser walls were rinsed with 10 mL of toluene
and the washing was added to the reaction mixture. The toluene and
excess thionyl chloride were removed under reduced pressure and the
light yellow liquid was held under vacuum pump for 45 min. This
pale yellow-colored oil weighed (9.98 g) and represented a yield of
62% as calculated from .sup.1H NMR. This ibuprofen acid chloride
was used directly for next reaction without further
purification.
[0039] Light Yellow Liquid; 62% yield, R.sub.f=0.62 (30% ethyl
acetate: 70% hexane).
[0040] .sup.1H NMR (CDCl.sub.3) .delta. 0.99 (d, 6H, J=6.64 Hz,
2.times.Me), 1.62 (d, 3H, J=7.06 Hz, Me), 1.95 (m, 1H, CH), 2.54
(d, 2H, J=7.19 Hz, CH.sub.2), 4.15 (q, 1H, J=7.05, CH), 7.22 (d,
2H, J=8.12 Hz, ArH), 7.27 (d, 2H, J=8.12 Hz, ArH).
[0041] .sup.13C NMR (CDCl.sub.3) .delta. 18.49, 22.21, 29.99,
44.84, 56.94, 127.50, 129.61, 134.56, 141.54, 175.30.
Example 3
Preparation of (S)-2-(2-Methoxynaphthalene-6-yl)propanoyl Chloride
[naproxen acid chloride]
##STR00007##
[0043] By the method and equipment described in Example 2, 25.8 g
(0.22 mol) of thionyl chloride was added via glass syringe to 10.0
g (0.043 mol) of (S)-2-(2-methoxynaphthalene-6-yl)propanoic acid
(also known as naproxen) in 60 mL of dry toluene at room
temperature under nitrogen atmosphere. The reaction mixture was
then heated at 130.degree. C. for 2.5 hr and worked up as
described. Evaporation in vacuo began to precipitate a light yellow
solid to which 40 mL of anhydrous hexane were added. The hexane and
the suspended yellow solid were stirred vigorously under dry
nitrogen atmosphere for 10 min and filtered to obtain, after vacuum
drying, 9.85 g of light yellow acid chloride. Dry hexane was added
(40 mL), and stirred for 10 min. under nitrogen. This crude product
was stored in a nitrogen flushed glass vial and used for the
coupling reaction without additional purification. The yield of
79%, from naproxen to the acid chloride, was determined by .sup.1H
NMR by integrating peak areas of residual starting material and
product.
[0044] Light Yellow solid; 79% yield, R.sub.f=0.39 (30% ethyl
acetate: 70% hexane).
[0045] .sup.1H NMR (CDCl.sub.3) .delta. 1.68 (d, 3H, J=6.91 Hz,
Me), 3.91 (s, 3H, OCH.sub.3), 4.24 (q, 1H, J=6.84 Hz, CH), 7.15
(brd, 2H, ArH), 7.19 (d, 1H, J=8.58 Hz, ArH), 7.69 (brd, 2H, ArH),
7.71 (d, 1H, J=8.8 Hz, ArH).
[0046] .sup.13C NMR (CDCl.sub.3) .delta. 18.63, 55.27, 57.33,
105.56, 118.98, 125.26, 126.14, 127.19, 128.84, 129.25, 132.42,
134.80, 157.69, 175.63.
Example 4
Preparation of
241-(4'-Chlorobenzoyl)-2-methyl-5-methoxy-1H-indol-3-yl)]ethanoyl
chloride [indomethacin acid chloride]
##STR00008##
[0048] With the apparatus as described in Example 2, a solution of
10.0 g (0.028 mol) of
2-[1-(4'-chlorobenzoyl)-2-methyl-5-methoxy-1H-indol-3-yl)]acetic
acid (indomethacin), 50 mL of dry methylene chloride, and 0.50 mL
anhydrous DMF was prepared under a blanket of dry nitrogen gas.
Oxalyl chloride (5.32 g, 0.042 mol) was added drop wise to this
solution at ambient temperature over 30 min. This reaction was not
heated in the silicone oil, but was stirred gently at room
temperature for 8 hr. The solvent and excess oxalyl chloride were
removed under vacuum while insuring that the temperature of the
contents remained below 40.degree. C. The solid obtained was
slurried with 30 mL of dry hexane, stirred for 10 min and filtered.
The pale gray solid indomethacin acid chloride (9.78 g) was dried
under vacuum for 1.0 hr and was used for the next reaction without
additional purification. The yield as determined by integration of
product and starting material peaks in the .sup.1H NMR was 92%.
Product was a light gray solid, R.sub.f=0.32 (5% methanol: 95%
methylene chloride)
[0049] .sup.1H NMR (CDCl.sub.3) .delta. 2.40 (s, 3H, CH.sub.3),
3.82 (s, 3H, OCH.sub.3), 4.16 (s, 2H, CH.sub.2), 6.69 (dd, 1H,
J=2.43, 8.96 Hz, ArH), 6.85 (m, 2H, ArH), 7.47 (d, 2H, J=8.43 Hz,
Ar), 7.66 (d, 2H, J=8.33 Hz, ArH).
[0050] .sup.13C NMR (CDCl.sub.3): .delta. 13.30, 42.34, 55.75,
100.90, 109.98, 112.11, 115.07, 129.13, 129.22, 129.76, 130.79,
131.17, 131.25, 133.51, 137.12, 139.65, 156.27, 168.23, 170.95.
Preparation of the 4-(hydroxymethyl)phenyl Carbonates
##STR00009##
[0052] Three discrete steps are required to prepare these
unsymmetrical aliphatic-aromatic carbonates. The preparation
commences with the synthesis of an aliphatic chloroformate
[R--O--CO--Cl], followed by its coupling to 4-hydroxybenzaldehyde,
and finally concludes with the subsequent reduction of the aldehyde
function. The specific route to both 4-(hydroxymethyl)phenyl
carbonates is described.
Example 5
Preparation of 4-(hydroxymethyl)phenyl 3,3-dimethylbutyl
Carbonate
Step 1--General Procedure for Preparation of Aliphatic
Chloroformates with Either Triphosgene or Phosgene
##STR00010##
[0054] Triphosgene (0.75 moles) dissolved in 200 mL of anhydrous
CH.sub.2Cl.sub.2 was cooled to 0.degree. C. and 1.0 moles of the
corresponding aliphatic alcohol [X.dbd.C or Si] were added drop
wise under nitrogen with stirring in a 500 mL round bottom fitted
with condenser and pressure equalized side-arm dropping funnel.
Then 1.20 moles of triethylamine in 50 mL of anhydrous methylene
chloride were added drop wise while maintaining the reaction
temperature below 4.degree. C. When addition was complete, the
solution was allowed to warm to 25.degree. C. and the fluid was
stirred for 16 hr. Anhydrous nitrogen gas was vigorously bubbled
through the solution for 1 hr to purge it of excess triphosgene.
The fluid contents were then poured into water, the organic layer
was separated (caution: pressure develops in the separatory
funnel), and the organics were dried over anhydrous MgSO.sub.4.
After evaporation of the solvents in vacuo, a vacuum distillation
yielded pure chloroformate as clear liquid in a 75-85% yield.
##STR00011##
[0055] Although somewhat more difficult to handle and more
hazardous, the same reaction can be carried out with phosgene gas
(1.2 molar equivalents as a 20 wt % solution of phosgene in
toluene). The phosgene-toluene was first cooled to -8.degree. C. to
-10.degree. C. and then the aliphatic alcohols (1.0 molar
equivalents in methylene chloride) are added drop wise followed by
1.2 molar equivalents of triethylamine. The reaction temperature
was held at or below -5.degree. C. until all additions were
completed. The solution was then allowed to warm to 25.degree. C.
and held at that temperature for 14 hr. The fluid was purged with
N.sub.2 for 2.0 hr to remove excess phosgene, filtered through a
layer of MgSO.sub.4 and upon vacuum distillation pure chloroformate
was obtained as a clear liquid. Yields were equivalent by these two
methods.
[0056] [In Step 1 for Example 11, below, 3-methylbutanol was the
corresponding aliphatic alcohol employed to generate the
chloroformate (CH.sub.3).sub.2CH--CH.sub.2CH.sub.2--O--CO--Cl].
Step 2--Synthesis of 4-Formylphenyl 3,3-Dimethylbutyl Carbonate
##STR00012##
[0058] Freshly prepared 3,3-dimethylbutyl chloroformate (24.3 g,
0.147 moles) was added to a solution of 4-hydroxybenzaldehyde (15.0
g, 0.123 moles) in 100 mL THF in a round-bottom flask which had
been pre-chilled to -5.degree. C. in an acetone-ice-salt mixture
under nitrogen atmosphere. Triethylamine (14.9 g, 0.147 moles) was
added to the reaction mixture via syringe over a period of 20 min.
Precipitation was observed almost instantly and an additional 30 mL
of THF were added for more efficient stirring. The reaction mixture
was slowly warmed to 18.degree. C.-20.degree. C., stirring was
continued for 12 hr and 75 mL of water was added. The organic layer
was separated and the aqueous layer was extracted with ethyl
acetate (3.times.30 mL). The combined organic extracts were washed
with brine, dried over anhydrous Na.sub.2SO.sub.4, and filtered.
The solvent was removed by rotary vacuum evaporation under reduced
pressure to give 38.5 g of a viscous oil, which was held for 1.0 hr
under vacuum pump, flushed with nitrogen and weighed. TLC on silica
plates with 18% ethyl acetate: 82% hexane as the mobile phase
showed a product spot at R.sub.f 0.57, a small amount of unreacted
4-hydroxybenzaldehyde at R.sub.f 0.25 and a trace of a byproduct at
R.sub.f 0.05. Pure 4-formylphenyl 3,3-dimethylbutyl carbonate (26.6
g, 86% yield) could be obtained by column chromatography of the
crude oil on a silica column with 12% ethyl acetate: 88% hexane as
the mobile phase. White needle-like crystals of product were
obtained which could readily be recrystallized from ether:hexane to
high purity. The yield in next step reduction reaction has been
evaluated on both the crude formyl and on the chromatographically
purified formyl. Purification of the formyl precursor does not
affect the yield of 4-(hydroxymethyl)phenyl 3,3-dimethylbutyl
carbonate. White needles (ether-hexane), mp 214-216.degree. C.,
R.sub.f=0.57 (18% ethyl acetate: 82% hexane)
[0059] .sup.1H NMR (CDCl.sub.3) .delta. 0.96 (s, 9H, 3.times.Me),
1.68 (t, 2H, J=7.40 Hz, CH.sub.2), 4.32 (t, 2H, J=7.36 Hz,
CH.sub.2), 7.28 (d, 2H, J=6.90 Hz, ArH), 8.13 (d, 2H, J=6.90 Hz,
ArH), 9.98 (s, 1H, CHO).
[0060] .sup.13C NMR (CDCl.sub.3) .delta. 29.52, 29.67, 41.60,
67.02, 121.14, 126.89, 131.92, 152.93, 155.34, 171.33. Anal. calcd
for C.sub.14H.sub.18O.sub.4 H.sub.2O; C, 62.67; H, 7.51. Found: C,
62.80; H, 6.76.
[0061] [In Step 2 for Example 11 3-methylbutyl chloroformate was
the chloroformate used to generate the target aldehyde,
(CH.sub.3).sub.2CH--CH.sub.2CH.sub.2--O--CO--O--C.sub.6H.sub.4--CHO-p].
Step 3A--Synthesis of 4-(Hydroxymethyl)phenyl 3,3-dimethylbutyl
Carbonate
[Formyl Reduction]
##STR00013##
[0063] There are two different experimental methods which produce
the hydroxymethylphenol carbonates: 4-(hydroxymethyl)phenyl
3,3-dimethylbutyl carbonate and 4-(hydroxymethyl)phenyl
2-(trimethylsilyl)ethyl carbonate. The Formyl Reduction method
begins with a 4-hydroxybenzaldehyde which, because it possesses
only a single hydroxyl, can be unambiguously chloroformylated on
the phenolic hydroxyl. Hydride reduction yields the titled product
of Step 3A above. However, under basic pH and low temperature
conditions p-hydroxybenzyl alcohol can be directly and selectively
chloroformylated on its phenolic hydroxyl. This Direct Selective
Acylation is discussed as Step 3B.
[0064] Formyl Reduction is carried out in an aqueous slurry of 4.99
g (0.132 moles) NaBH.sub.4 prepared in 25 mL of ice-cold distilled
water. A solution of 80 mL THF and 11.0 g (0.044 moles) of
4-formylphenyl 3,3-dimethylbutyl carbonate was cooled to -8.degree.
C. The aqueous slurry of sodium borohydride was added slowly to the
formyl compound over a period of 30 min. The temperature of the
medium rose to 0.degree. C. during addition but continuous stirring
for 2 hr in the acetone-ice-salt bath dropped the temperature of
the reaction mixture to approximately -10 to -8.degree. C. The
reaction was allowed to gradually warm to 0.degree. C. over 2.5 hr
with continuous stirring. The reaction mixture was then diluted
with 50 mL of saturated aqueous NH.sub.4Cl solution at 18.degree.
C., extracted with ether (3.times.25 mL), and the combined organic
extracts were washed with 30 mL of brine solution, dried over
anhydrous MgSO.sub.4, and filtered. The solvent was removed by
means of a rotary vacuum evaporator to obtain a viscous liquid,
which was purified upon passing through silica gel column using
hexane:ethyl acetate (4:1) as eluent to give 10.2 g of white
microcrystals.
[0065] White solid, 91% yield, mp 62-63.degree. C. (recrystallized
from ether-hexane), R.sub.f=0.24 (20% ethyl acetate: 80%
hexane).
[0066] .sup.1H NMR (CDCl.sub.3) .delta. 0.94 (s, 9H, 3.times.Me),
1.66 (t, 2H, J=7.63 Hz, CH.sub.2), 1.84 (s, 1H, OH), 4.28 (t, 2H,
J=7.54 Hz, CH.sub.2), 4.64 (d, 2H, J=5.91 Hz, CH.sub.2), 7.13 (d,
2H, J=8.54 Hz, ArH), 7.34 (d, 2H, J=8.56 Hz, ArH).
[0067] .sup.13C NMR (CDCl.sub.3) .delta. 29.52, 29.65, 41.63,
64.63, 66.67, 121.14, 128.01, 138.64, 150.53, 153.74. Anal. calcd.
for C.sub.14H.sub.20O.sub.4: C, 66.65; H, 7.99. Found: C, 66.29; H,
7.82.
[0068] [In Step 3 for Example 11
(CH.sub.3).sub.2CH--CH.sub.2CH.sub.2--O--CO--O--C.sub.6H.sub.4--CHO-p
was the precursor of the para-substituted benzyl alcohol,
(CH.sub.3).sub.2CH--CH.sub.2CH.sub.2--O--CO--O--C.sub.6H.sub.4--CH.sub.2O-
H].
Step 3B--Synthesis of 4-(Hydroxymethyl)phenyl 3,3-Dimethylbutyl
Carbonate
[Direct Selective Acylation]
##STR00014##
[0070] Direct Selective Acylation was effected by first dissolving
0.252 g of 3,3-dimethylbutyl chloroformate (1.0 eq, 1.00 mmol, 158
.mu.L) in a pre-cooled solution of 0.137 g p-hydroxybenzyl alcohol
(also known as 4-hydroxybenzyl alcohol or 4-(hydroxymethyl)phenol)
(1.1 eq, 1.10 mmol) in 5 mL of THF under nitrogen atmosphere.
Triethylamine (1.0 eq, 1 mmol, 139 .mu.L) was added over a 20 min
period via syringe. Upon precipitation, 3 mL of THF was added to
the reaction mixture to ensure efficient stirring. The reaction
mixture was slowly warmed up to 18-20.degree. C. and kept stirring
for 12 hr. Distilled water (8 mL) was added and the organic layer
was separated from the aqueous layer. The aqueous layer was then
extracted with ethyl acetate (3.times.15 mL). The combined organic
extracts were washed with brine and dried over anhydrous magnesium
sulfate. The solvent was removed by rotary evaporation under
reduced pressure, resulting in a clear, viscous oil (0.22 g, 87%).
The crude product was purified upon passing through a silica gel
column using 99% methylene chloride: 1% methanol as eluent to give
a pure, clear liquid (0.14 g, 56%). The product was
chromatographically and spectrally identical with that prepared by
Formyl Reduction in Step 3A above.
Example 6
Preparation of 4-(hydroxymethyl)phenyl 2-(trimethylsilyl)ethyl
Carbonate
Step 1--General Procedure for Preparation of Aliphatic
Chloroformates with Either Triphosgene or Phosgene
[0071] Following the procedure described under Example 5, Step 1,
with 2-(trimethylsilyl)ethanol and triphosgene, a 75% yield of
2-(trimethylsilyl)ethyl chloroformate was obtained which was used
without purification in Step 2 below.
Step 2--Synthesis of 4-formylphenyl 2-(trimethylsilyl)ethyl
carbonate
##STR00015##
[0073] Into a 250 mL three-neck round bottom flask fitted with a
condenser, rubber serum-capped joint, and gas bubbler was charged a
solution of 4-hydroxybenzaldehyde (8.0 g, 0.066 mol) in THF (70
mL). This solution maintained under nitrogen atmosphere was
pre-cooled to -5.degree. C. in an acetone-ice-salt slurry and
2-(trimethylsilyl)ethyl chloroformate (15.4 g, 0.085 mol) was
added. Subsequently, triethylamine (8.68 g, 0.085 mol) was added
drop wise to the reaction mixture via syringe over a period of 20
min. The reaction mixture was allowed to slowly warm to 18.degree.
C.-20.degree. C. with continuous stirring (14 hr). Water (50 mL)
was added, the organic layer separated, and the aqueous layer
extracted with ethyl acetate (3.times.25 mL). The combined organic
extracts were washed with brine, dried over anhydrous
Na.sub.2SO.sub.4, filtered, and the solvent was removed by
evaporation in vacuo to give 22.2 g of a light yellow viscous oil.
The crude formyl compound was purified on a silica gel column using
7% ethyl acetate: 93% hexane as eluent. The purified yield was 13.4
g of white crystals (76%).
[0074] Yield of 76%, mp 194-196.degree. C. after recrystallization
from ether-hexane, R.sub.f=0.63 (15% ethyl acetate: 85%
hexane).
[0075] .sup.1H NMR (CDCl.sub.3) .delta. 0.07 (s, 9H, 3.times.Me),
1.14 (t, 2H, J=8.6 Hz, CH.sub.2), 4.36 (t, 2H, J=8.5 Hz, CH.sub.2),
4.65 (s, 2H, CH.sub.2), 7.13 (d, 2H, J=8.4 Hz, Ar), 7.28 (d, 2H,
J=8.4 Hz, ArH).
[0076] .sup.13C NMR (CDCl.sub.3) .delta. -1.55, 17.55, 67.92,
121.19, 126.82, 131.92, 152.90, 155.39, 170.91. Anal. calcd. for
C.sub.13H.sub.18O.sub.4Si, 0.25; H.sub.2O, C, 57.62; H, 6.88.
Found: C, 57.54; H, 6.70.
Step 3A--Synthesis of 4-(Hydroxymethyl)phenyl
2-(Trimethylsilyl)ethyl Carbonate
[Formyl Reduction]
##STR00016##
[0078] Formyl Reduction was effected in an aqueous slurry of 4.26 g
(0.113 moles) NaBH.sub.4 prepared in 22 mL of ice-cold distilled
water. A solution of 70 mL THF and 10.0 g (0.038 moles) of
4-formylphenyl 2-(trimethylsilyl)ethyl carbonate was cooled to
-8.degree. C. The aqueous slurry of sodium borohydride was added
slowly to the formyl compound over a period of 30 min. The
temperature of the medium rose to 0.degree. C. during addition but
continuous stirring for 2 hr in the acetone-ice-salt bath dropped
the temperature of the reaction mixture to approximately -10 to
-8.degree. C. The reaction was allowed to gradually warm to
0.degree. C. over 2 hr with continuous stirring. The reaction
mixture was then diluted with 50 mL of saturated NH.sub.4Cl
solution at 18.degree. C., extracted with ether (3.times.25 mL),
and the combined organic extracts were washed with 30 mL of brine
solution, dried over anhydrous MgSO.sub.4, and filtered. The
solvent was removed by means of a rotary vacuum evaporator to
obtain a viscous liquid, which was purified upon passing through
silica gel column using hexane:ethyl acetate (4:1) as eluent to
give 8.5 (84%) yield of a colorless thick oil.
[0079] Colorless oil, R.sub.f=0.25 (82% hexane:18% ethyl
acetate).
[0080] .sup.1H NMR (CDCl.sub.3) .delta. 0.05 (s, 9H, 3.times.Me),
1.11 (t, 2H, J=6.71 Hz, CH.sub.2), 2.29 (brs, 1H, OH), 4.33 (t, 2H,
J=7.30 Hz, CH.sub.2), 4.65 (s, 2H, CH.sub.2), 7.13 (d, 2H, J=8.85
Hz, Ar), 7.32 (d, 2H, J=8.70 Hz, ArH).
[0081] .sup.13C NMR (CDCl.sub.3) .delta. -1.61, 17.46, 64.47,
67.36, 121.10, 127.96, 138.59, 150.43, 153.70. Anal. calcd. for
C.sub.13H.sub.20O.sub.4Si: C, 58.18; H, 7.51. Found: C, 57.74; H,
7.49.
Step 3B--Synthesis of 4-(Hydroxymethyl)phenyl
2-(Trimethylsilyl)ethyl Carbonate
[Direct Selective Acylation]
##STR00017##
[0083] Direct Selective Acylation begins with 1.53 g of
2-(trimethylsilyl)ethyl chloroformate (2.6 eq, 8.6 mmol, 1.53 mL)
added to a pre-cooled (-5.degree. C.) solution of 0.41 g
p-hydroxybenzyl alcohol (1.0 eq, 3.3 mmol) in THF (5 mL) under
nitrogen atmosphere. Triethylamine 0.33 g (1.0 eq, 3.3 mmol, 459
.mu.l) was added to the reaction mixture via syringe over a 20 min
period. The reaction mixture was slowly warmed up to 18-20.degree.
C. with continuous stirring for 14 hr. Distilled water (5 mL) was
added and the organic layer was separated out. The aqueous layer
was then extracted with ethyl acetate (3.times.15 mL) and the
combined organic extracts were washed with brine and dried over
anhydrous magnesium sulfate. Ethyl acetate was removed by rotary
evaporation under reduced pressure, resulting in light yellow oil
(0.62 g, 70%). The product was chromatographically and spectrally
identical to that prepared by Formyl Reduction described in Step 3A
above.
General Procedure for Synthesis of the NSAID Carbonates Containing
the p-Hydroxybenzyl Alcohol Linker, n=1 in Formula 1 [Method A]
##STR00018##
[0084] A reaction mixture containing 1.2 mmol of either
4-(hydroxymethyl)phenyl 3,3-dimethylbutyl carbonate or
4-(hydroxymethyl)phenyl 2-(trimethylsilyl)ethyl carbonate and 1.3
mmol of acid chloride of an appropriate NSAID (ibuprofen, naproxen
and indomethacin) in 20 mL of anhydrous THF was chilled to
-5.degree. C. in an ice-salt bath. Triethylamine (4 mmol) was added
drop wise over 20 min, holding the temperature below -5.degree. C.
Triethylammonium chloride precipitated. The reaction mixture was
stirred below -5.degree. C. for an additional 1.0 hr and then
gradually allowed to warm to 18.degree. C. with continuous stirring
for 7-12 hr, or until all the NSAID acid chloride had been consumed
(as determined by TLC). Water (30 mL) was added to the reaction
mixture, and the resulting fluid was extracted with ethyl acetate
(3.times.30 mL). The combined organic phase was washed with brine,
dried and concentrated under reduced pressure. The crude products
were purified on a silica gel column chromatography using 10% ethyl
acetate-90% hexane as eluent. As an identification marker each
product was characterized by its R.sub.f on silica gel TLC with an
optimized mixed solvent mobile phase. Melting points are reported
for those compounds which crystallized. The yields, TLC, combustion
analyses, and NMR spectra are reported with each example. [In
Example 11 the NSAID used was (S)-naproxen and the benzyl alcohol
was
(CH.sub.3).sub.2CH--CH.sub.2CH.sub.2--O--CO--O--C.sub.6H.sub.4--CH.sub.2O-
H.]
Example 7
Preparation of 4-[{2-(4-isobutylphenyl)propanoyloxy}methyl]phenyl
3,3-dimethylbutyl carbonate
[0085] By the above general method the titled compound was prepared
in 48% yield.
##STR00019##
[0086] Colorless oil, 48% yield, R.sub.f=0.43 (90% hexane: 10%
ethyl acetate)
[0087] .sup.1H NMR (CDCl.sub.3) .delta. 0.92 (d, J=6.60 Hz, 6H,
2.times.Me), 0.99 (s, 9H, 3.times.Me), 1:51 (d, J=7.17 Hz, 3H, Me),
1.69 (t, J=7.47 Hz, 2H, CH.sub.2), 1.86 (m, 1H, CH), 2.46 (d,
J=7.17 Hz, 2H, CH.sub.2), 3.75 (q, J=7.13, 1H, CH), 4.32 (t, J=7.65
Hz, 2H, CH.sub.2), 5.09 (s, 2H, CH.sub.2), 7.09 (d, 2H, J=7.96 Hz,
ArH), 7.11 (d, 2H, J=8.43 Hz, Ar), 7.19 (d, 2H, J=8.12 Hz, ArH),
7.22 (d, 2H, J=8.86 Hz, ArH).
[0088] .sup.13C NMR (CDCl.sub.3) .delta. 18.23, 22.24, 29.41,
29.51, 30.03, 41.51, 44.89, 44.96, 65.35, 66.47, 120.91, 127.07,
128.82, 129.19, 133.72, 137.43, 140.39, 150.70, 153.45, 174.16.
Anal. Calcd. for (C.sub.27H.sub.36O.sub.5 0.5H.sub.2O): C, 72.11;
H, 8.28. Found: C, 72.22; H, 8.08.
Example 8
Preparation of 4-[{2-(4-isobutylphenyl)propanoyloxy}methyl]phenyl
2-(trimethylsilyl)ethyl carbonate
[0089] By the above general method the titled compound was prepared
in 56% yield.
##STR00020##
[0090] Colorless oil, 56% yield, R.sub.f=0.62 (85% hexane: 15%
ethyl acetate).
[0091] .sup.1H NMR (CDCl.sub.3) .delta. 0.09 (s, 9H, 3.times.Me),
0.91 (d, 6H, J=6.65 Hz, 2.times.Me), 1.14 (t, 2H, J=7.85 Hz,
CH.sub.2), 1.51 (d, 3H, J=7.15 Hz, CH.sub.3), 1.86 (m, 1H, CH),
2.46 (d, 2H, J=7.15 Hz, CH.sub.2), 3.74 (q, 1H, J=7.15 Hz, CH),
4.35 (t, 2H, J=8.75 Hz, CH.sub.2), 5.08 (s, 2H, CH.sub.2), 7.09 (d,
2H, J=7.95 Hz, ArH), 7.11 (d, 2H, J=8.5 Hz, Ar), 7.19 (d, 2H,
J=8.05 Hz, ArH), 7.23 (d, 2H, J=8.60 Hz, ArH).
[0092] .sup.13C NMR (CDCl.sub.3) .delta. -1.60, 17.47, 18.30,
22.31, 30.11, 44.97, 45.05, 65.49, 67.34, 121.04, 127.14, 128.92,
129.27, 133.75, 137.49, 140.52, 150.80, 153.51, 174.32. Anal.
calcd. for C.sub.26H.sub.36O.sub.5Si: C, 68.39; H, 7.95. Found: C,
68.37; H, 7.94.
Example 9
Preparation of
4-[{2-(2-Methoxynaphthalen-6-yl)propanoyloxy}methyl]phenyl
3,3-dimethylbutyl carbonate
##STR00021##
[0094] White solid, 62% yield, mp 63-64.degree. C., R.sub.f=0.44
(80% hexane: 20% ethyl acetate).
[0095] .sup.1H NMR (CDCl.sub.3) .delta. 0.96 (s, 9H, 3.times.Me),
1.57 (d, 3H, J=7.16 Hz, Me), 1.67 (t, 2H, J=7.59 Hz, CH.sub.2),
3.89 (q, 1H, J=7.14 Hz, CH), 3.94 (s, 3H, OMe), 4.29 (t, 2H, J=7.48
Hz, CH.sub.2), 5.08 (q, 2H, J=12.55 Hz, CH.sub.2), 7.08 (brd, 2H,
J=8.52 Hz, ArH), 7.10 (d, 1H, J=2.41 Hz, Ar), 7.13 (dd, 1H, J=2.52,
8.87 Hz, Ar), 7.23 (brd, 2H, J=8.49 Hz, ArH), 7.37 (dd, 1H, J=1.79,
8.5 Hz, ArH), 7.63 (brs, 1H, ArH), 7.67 (d, 1H, J=8.77 Hz, ArH),
7.68 (d, 1H, J=8.39 Hz, ArH).
[0096] .sup.13C NMR (CDCl.sub.3) .delta. 18.44, 29.53, 29.66,
41.65, 45.44, 55.28, 65.70, 66.68, 105.64, 118.97, 121.09, 125.97,
126.21, 127.15, 128.93, 129.13, 129.27, 133.72, 133.76, 135.46,
150.89, 153.58, 157.68, 174.32. Anal. calcd. for
C.sub.28H.sub.32O.sub.6: C, 72.39; H, 6.94. Found: C, 72.37; H,
7.13.
Example 10
4-[{2-(2-Methoxynaphthalen-6-yl)propanoyloxy}methyl]phenyl
2-(trimethylsilyl)ethyl carbonate
##STR00022##
[0098] White solid, 64% yield, mp 58-59.degree. C., R.sub.f=0.49
(80% hexane: 20% ethyl acetate).
[0099] .sup.1H NMR (CDCl.sub.3) .delta. 0.06 (s, 9H, 3.times.Me),
1.12 (t, 2H, J=8.70 Hz, CH.sub.2), 1.56 (d, 3H, J=7.16 Hz,
CH.sub.3), 3.87 (q, 1H, J=7.16 Hz, CH), 3.90 (s, 3H, OMe), 4.32 (t,
2H, J=8.68 Hz, CH.sub.2), 5.08 (q, 2H, J=12.54 Hz, CH.sub.2), 7.07
(brd, 2H, J=8.52 Hz, ArH), 7.10 (d, 1H, J=2.39 Hz, Ar), 7.12 (dd,
1H, J=2.51, 8.88 Hz, ArH), 7.22 (brd, 2H, J=8.44 Hz, ArH), 7.37
(dd, 1H, J=1.78, 8.50 Hz, ArH), 7.62 (brs, 1H, ArH), 7.66 (d, 1H,
J=8.78 Hz, ArH), 7.68 (d, 1H, J=8.40 Hz, ArH)
[0100] .sup.13C NMR (CDCl.sub.3) .delta. -1.55, 17.54, 18.45,
45.46, 55.30, 65.73, 67.42, 105.66, 118.98, 121.13, 125.98, 126.22,
127.16, 128.94, 129.14, 129.28, 133.72, 135.48, 150.92, 153.55,
157.69, 174.33. Anal. calcd. for C.sub.27H.sub.32O.sub.6Si: C,
67.47; H, 6.71. Found: C, 67.91; H, 7.03
Example 11
Preparation of
4-[{2-(2-Methoxynaphthalen-6-yl)propanoyloxy}methyl]phenyl
3-methylbutyl carbonate
[0101] This target compound was prepared by the same three general
steps as discussed under Example 5 above.
Step 2--Synthesis of 4-Formylphenyl 3-Methylbutyl Carbonate
##STR00023##
[0103] From 3-methylbutyl chloroformate and p-hydroxybenzaldehyde
following the general method described under Example 5 this
aldehyde carbonate was obtained in 67% yield as a viscous oil.
[0104] .sup.1H NMR (CDCl.sub.3) .delta. 0.96 (d, 6H, J=7.41 Hz,
2.times.Me), 1.71 (m, H, J=7.40 Hz, J=7.38, CH), 1.62 (m, 2H,
J=7.38 Hz, CH.sub.2), 4.29 (t, 2H, J=7.38 Hz, CH.sub.2), 7.34 (d,
2H, J=6.90 Hz, ArH), 7.90 (d, 2H, J=6.90 Hz, ArH), and 9.97 ppm (s,
1H, CHO).
[0105] .sup.13C NMR (CDCl.sub.3) .delta. 22.38, 24.81, 38.17,
67.95, 121.7, 131.2, 134.1, 152.9, 155.6, 190.7.
Step 3--Synthesis of 4-(Hydroxymethyl)phenyl 3-Methylbutyl
Carbonate
##STR00024##
[0107] Following the general method described in Step 3 under
Example 5 this target benzyl alcohol was obtained in 77% yield.
[0108] .sup.1H NMR (CDCl.sub.3) .delta. 0.95 (d, 6H, J=7.40 Hz,
2.times.Me), 1.74 (m, H, J=7.40 Hz, J=7.38, CH), 1.63 (m, 2H,
J=7.38 Hz, CH.sub.2), 4.25 (m, two overlapping methylenes, 4H, two
CH.sub.2), 4.65 (s, 1H, OH), 7.14 (d, 2H, J=6.80 Hz, ArH), and 7.34
ppm (d, 2H, J=6.80 Hz, ArH).
Step 4--Synthesis of
4-[{2-(2-Methoxynaphthalen-6-yl)propanoyloxy}methyl]phenyl
3-methylbutyl carbonate
##STR00025##
[0110] This 4-(hydroxymethyl)phenyl 3-methylbutyl carbonate,
prepared in Step 3 (above) was reacted with (S)-naproxen acid
chloride as described in the General Procedure for Synthesis of the
NSAID Carbonates [Method A]. A 29% yield of Example 11 was prepared
as a clear oil.
[0111] .sup.1H NMR (CDCl.sub.3) .delta. 0.96 (d, 6H, J=7.40 Hz,
2.times.Me), 1.57 (d, 3H, J=7.16 Hz, Me), 2.00 (m, 2H, CH.sub.2),
3.95 (two overlapping and m, 2H, J=7.14 Hz, two CH), 3.98 (s, 3H,
OMe), 4.59 (t, 2H, J=7.48 Hz, CH.sub.2), 5.08 (q, 2H, J=12.6 Hz,
benzylic CH.sub.2), 7.08 to 7.89 (m, 10H, ArH).
Example 12
4-[[2-{1-(4''-Chlorobenzoyl)-2-methyl-5-methoxy-1H-indol-3-yl}ethanoyl]met-
hyl]phenyl 3,3-dimethylbutyl carbonate
##STR00026##
[0113] Yellow liquid, 55% yield, R.sub.f=0.5 (75% hexane: 25% ethyl
acetate)
[0114] .sup.1H NMR (CDCl.sub.3) .delta. 0.96 (s, 9H, 3.times.Me),
1.67 (t, 2H, J=7.56 Hz, CH.sub.2), 2.33 (s, 3H, CH.sub.3), 3.67 (s,
2H, CH.sub.2), 3.72 (s, 3H, OMe), 4.29 (t, 2H, J=7.46 Hz,
OCH.sub.2), 5.09 (s, 2H, OCH.sub.2), 6.64 (dd, 1H, J=2.52, 9.01 Hz,
ArH), 6.87 (d, 1H, J=9.0 Hz, ArH), 6.92 (d, 1H, J=2.48 Hz, ArH),
7.11 (dd, 2H, J=1.9, 6.59 Hz, ArH), 7.27 (d, 2H, J=8.59 Hz, ArH),
7.41 (dd, J=1.82, 6.70 Hz, 2H, ArH), 7.60 (dd, 2H, J=1.87, 6.64 Hz,
ArH).
[0115] .sup.13C NMR (CDCl.sub.3) .delta. 13.09, 29.32, 29.42,
30.09, 41.42, 55.33, 65.71, 66.44, 101.04, 111.58, 112.18, 114.73,
120.94, 128.84, 129.10, 130.32, 130.58, 130.91, 133.32, 133.73,
135.63, 138.87, 150.81, 153.30, 155.86, 167.88, 170.22.
[0116] Anal. calcd. for C.sub.33H.sub.34ClNO.sub.7: C, 66.94; H,
5.79; N, 2.37. Found C, 66.64; H, 5.97; N, 2.42.
Example 13
4-[[2-{1-(4'-Chlorobenzoyl)-2-methyl-5-methoxy-1H-indol-3-yl}ethanoyl]meth-
yl]phenyl 2-(trimethylsilyl)ethyl carbonate
##STR00027##
[0118] Yellow liquid, 59% yield, R.sub.f=0.55 (75% hexane: 25%
ethyl acetate).
[0119] .sup.1H NMR (CDCl.sub.3) .delta. 0.07 (s, 9H, 3.times.Me),
1.13 (t, 2H, J=8.66 Hz, CH.sub.2), 2.35 (s, 3H, CH.sub.3), 3.69 (s,
2H, CH.sub.2), 3.75 (s, 3H, OMe), 4.34 (t, 2H, J=8.65 Hz,
CH.sub.2), 5.10 (s, 2H, CH.sub.2), 6.65 (dd, 1H, J=2.53, 9.0 Hz,
ArH), 6.87 (d, 1H, J=9.03 Hz, ArH), 6.91 (d, 1H, J=2.49 Hz, ArH),
7.12 (dd, 2H, J=1.91, 8.58 Hz, ArH), 7.29 (d, 2H, J=8.57 Hz, ArH),
7.44 (dd, 2H, J=1.84, 8.86 Hz, ArH), 7.63 (dd, 2H, J=1.89, 8.89 Hz,
ArH).
[0120] .sup.13C NMR (CDCl.sub.3) .delta. -1.62, 13.25, 17.45,
30.29, 55.55, 65.93, 67.38, 101.17, 111.75, 112.31, 114.88, 121.15,
129.02, 129.28, 130.46, 130.73, 131.07, 133.38, 133.85, 135.84,
139.13, 150.99, 153.44, 156.00, 168.14, 170.44.
[0121] Anal. calcd. for C.sub.32H.sub.34ClNO.sub.7Si: C, 63.20; H,
5.64; N, 2.30. Found: C, 63.06; H, 5.67; N, 2.30.
Example by METHOD B
[0122] These 4-(hydroxymethyl)phenyl carbonates [5, 6, and 5
desmethyl] of the two types shown below can also be coupled to the
NSAID carboxylic acids without first converting those acids to
their acid chlorides (as described in Method A). Other types of in
situ "activation" of the NSAID carboxyl are also satisfactory
syntheses of the target carbonates. Carbonyldiimidazole,
carbodiimides, or Mitsunobu conditions can catalyze the coupling of
the 4-(hydroxymethyl)phenyl carbonates to the NSAID acids (as
described in Method B). Yields tended to be lower from Method B
compared to those obtained from the acid chlorides. A typical
example (Example 14) follows.
##STR00028##
Example 14
Preparation of [o-(2,6-dichloroanilino)phenyl]acetyl
3,3-dimethylbutyl carbonate
##STR00029##
[0124] Diclofenac (0.83 mmol, 0.25 g) and 1,1'-carbonyldiimidazole
(1.0 mmol, 0.16 g) were combined in dry CH.sub.2Cl.sub.2 (3 mL) and
agitated with a magnetic stirrer for 30 min.
4-(Hydroxymethyl)phenyl 3,3-dimethylbutyl carbonate (1.43 mmol,
0.32 g) in CH.sub.2Cl.sub.2 (2 mL) was added dropwise and the
reaction was refluxed at 57.degree. C. for 16 hr. Distilled water
(30 mL) was added and the aqueous layer was extracted with
CH.sub.2Cl.sub.2 (2.times.30 mL), washed with brine (60 mL) and
dried over anhydrous magnesium sulfate. The solvent was evaporated
to yield a crude yellow oil which was purified using column
chromatography on silica gel with 85% hexane: 15% ethyl acetate as
the eluent to yield 0.23 g of product as a clear oil.
[0125] Clear viscous oil, 53%, R.sub.f=0.47 (90% hexane: 10% ethyl
acetate).
[0126] .sup.1H NMR (500 MHz, CDCl.sub.3): .delta. 7.31 (d, 2H,
J=8.06 Hz), 7.23 (dd, 4H, J=8.67, 100.3 Hz), 7.21 (dd, 1H, J=1.43,
7.50 Hz), 7.13 (dt, 1H, J=1.53, 6.82 Hz), 6.95 (m, 2H), 6.84 (bs,
1H), 6.54 (d, 1H, J=8.03 Hz), 5.14 (s, 2H), 4.29 (t, 2H, J=7.54
Hz), 3.84 (s, 2H), 1.66 (t, 2H, J=7.62 Hz), 0.95 (s, 9H). Anal.
Calcd. for C.sub.28H.sub.29Cl.sub.2NO.sub.5: C, 63.40; H, 5.51; N,
2.64. Found: C, 63.22; H, 5.45; N, 2.63.
Example 15
Preparation of [o-(2,6-dichloroanilino)phenyl]acetyl
2-(trimethylsilyl)ethyl carbonate
[0127] Following the procedure described for Example 14 but with
the substitution of 4-(hydroxymethyl)phenyl 2-(trimethylsilyl)ethyl
carbonate instead of the 4-(hydroxymethyl)phenyl 3,3-dimethylbutyl
carbonate the title compound was prepared in 37% yield. Physical
properties for the product appear below.
##STR00030##
[0128] Diclofenac (0.60 mmol, 0.18 g) and CDI (0.66 mmol, 0.11 g)
were combined in dry CH.sub.2Cl.sub.2 (2 mL) and left stirring at
room temperature for 30 min. 4-(Hydroxymethyl)phenyl
2-(trimethylsilyl)ethyl carbonate (0.6 mmol, 0.16 g) in
CH.sub.2Cl.sub.2 (2 mL) was added drop wise. The solution was
stirred at room temperature for 3 days. Distilled water (30 mL) was
added and the aqueous layer was extracted with CH.sub.2Cl.sub.2
(2.times.30 mL), washed with brine (60 mL) and dried over anhydrous
magnesium sulfate. The solvent was evaporated to yield crude yellow
oil which was purified using column chromatography with 80% hexane:
20% ethyl acetate as the eluent to yield 0.12 g of the product as a
clear oil.
[0129] Yield 37%, R.sub.f=0.58 (90% hexane: 10% ethyl acetate).
[0130] .sup.1H NMR (500 MHz, CDCl.sub.3): .delta. 7.31 (d, 2H,
J=8.07 Hz), 7.23 (dd, 4H, J=8.62, 101 Hz), 7.21 (dd, 1H, J=1.43,
7.54 Hz), 7.11 (dt, 1H, J=7.56 Hz), 6.95 (m, 2H), 6.84 (bs, 1H),
6.53 (d, 1H, J=8.02 Hz), 5.14 (s, 2H), 4.32 (t, 2H, J=8.40 Hz),
3.83 (s, 2H), 1.12 (t, 2H, J=8.94 Hz), 0.05 (s, 9H).
Example by METHOD C
[0131] Method A and Method B construct the target by synthetic
sequences which build the final molecule through the key
intermediacy of either a 4-(hydroxymethyl)phenyl 3,3-dimethylbutyl
carbonate (5) or a 4-(hydroxymethyl)phenyl 2-(trimethylsilyl)ethyl
carbonate (6). In both methods the NSAID acid is coupled to the
benzylic hydroxyl in an ultimate step as an acid chloride (Method
A) or as an in situ activated carboxylic acid (Method B). As a
third alternative (Method C), one can take advantage of an initial
selective esterification of an aliphatic carbinol in the presence
of a phenol. In this fashion one can construct the NSAID ester to
the hydroxymethylphenol in an initial step and react the remaining
phenolic --OH to a chloroformate in a second step. In general, the
overall yields by this method are inferior to those of Methods A or
B. Example 16 demonstrates the Method C pathway.
Example 16
Preparation of 4-[{2-(4-isobutylphenyl)propanoyloxy}methyl]phenyl
2-(trimethylammonium)ethyl carbonate iodide salt
[0132] Although choline chloroformate [2-(trimethylammonium)ethyl
chloroformate chloride salt] is readily available, we were unable
to condense it with p-hydroxybenzaldehyde as described above in
Step 2 under examples 5 or 6 and to obtain more than modest yields
of the carbonate. Furthermore, the salt-like character of the
trimethylammonium moiety thwarted a smooth hydride reduction of the
formyl function to the requisite benzyl alcohol, in satisfactory
yields. An alternative approach to this compound was required.
[0133] Resort was made to the observation of Appendino [G.
Appendino, A. Minassi, N. Daddario, F. Bianchi, and G. C. Tron,
Organic Letters, 2002, 4 (22), 3839-3841] that a Mitsunobu reaction
can selectively esterify the benzyl hydroxyl leaving the phenolic
hydroxyl untouched in p-hydroxymethylphenol.
Step 1--We applied Appendino's general procedure to the selective
condensation of the aliphatic hydroxyl in p-hydroxymethylphenol
with the carboxyl of 2-(4-isobutylphenyl)propionic acid (ibuprofen)
with triphenylphosphine (TPP) and diisopropyl azodicarboxylate
(DIAD) in anhydrous tetrahydrofuran (THF)
##STR00031##
[0135] To a pre-cooled (0.degree. C.) solution of 0.19 g of
p-hydroxybenzyl alcohol (1.5 mmol) and 0.31 g (1.5 mmol) of
2-(4-isobutylphenyl)propionic acid (ibuprofen) in dry THF (3.5 mL)
were added 0.39 g TPP (1.5 mmol) and 295 .mu.L DIAD (1.5 mmol). The
reaction was slowly warmed to room temperature and left stirring
under nitrogen atmosphere for 48 hr. Within 24 hr the reaction
solution turned from yellow to red-orange to brown. The THF was
evaporated to yield 0.94 g of a brown liquid. The liquid was
re-dissolved in ethyl acetate, washed with saturated sodium
bicarbonate, dried over anhydrous magnesium sulfate and
chromatographed on a silica gel column with 60% hexane: 40% ethyl
acetate to provide 42% of the benzyl ester. TLC with 80% hexane:
20% ethyl acetate indicated a single product spot and the absence
of TPP, DIAD, or ibuprofen.
[0136] .sup.1H NMR confirmed the structure of this phenol and the
material was used directly in the next synthetic step.
[0137] Yield 42% product, R.sub.f=0.21 (80% hexane: 20% ethyl
acetate).
[0138] .sup.1H NMR, (CDCl.sub.3) .delta. 7.31 (d, 2H, J=8.5 Hz,
meta-position to phenol), 7.27 (d, 2H, J=8.0 Hz, meta-position to
isobutyl group), 7.12 (d, 2H, J=8.0 Hz, ortho-position to isobutyl
group), 6.92 (d, 2H, J=8.5 Hz, ortho-position to phenol), 4.63 (s,
2H, --OCH.sub.2--Ar), 3.91 (q, 1H, J=7.0 Hz,
--CH--(CH.sub.3)--CO--), 2.45 (d, 2H, J=7.0 Hz,
(CH.sub.3).sub.2CH--CH.sub.2--Ar), 1.84 (septet, 1H, J=6.75 Hz,
(CH.sub.3).sub.2CH--), 1.58 (d, 3H, J=7.0 Hz,
Ar--CH(CH.sub.3)--CO--) and 0.89 ppm (d, 6H, J=6.5 Hz,
(CH.sub.3).sub.2--CH--).
Step 2--Synthesis of Phenol Chloroformate, Coupling to
N,N-Dimethylaminoethanol and Methylation Procedure
##STR00032##
[0140] In a one-pot, three-step reaction, the phenol was
chloroformylated, reacted with dimethylaminoethanol, and
subsequently methylated. A 10 mL round bottom flask was charged
with a stirring bar and 0.162 g of PVP (polyvinyl pyridine, 8.8
meq/g, 1.43 meq). The flask was placed under high vacuum for 45
min. The flask was filled with N.sub.2 and fitted with a rubber
septum. Dry CH.sub.2Cl.sub.2 (800 .mu.L) was introduced, and the
resulting mixture was slowly stirred. A solution of phosgene in
toluene (20% wt., d=0.94 g/mL, 0.188 g phosgene/mL solution, 899
.mu.L) was added. The flask was placed under a positive N.sub.2
pressure and immersed in an ice bath. From Step 1 above, the
ibuprofen benzyl ester of phenol (312.14 g/mol, 1.43 mmol, 445 mg)
in 800 .mu.L of dry CH.sub.2Cl.sub.2 was added drop wise to the
cold and gently stirred mixture. The ice bath
was removed after ten min. and the mixture was allowed to stir to
room temperature overnight. The mixture was diluted with 4 mL of
dry CH.sub.2Cl.sub.2 and purged with a stream of N.sub.2. The resin
was removed by filtration through a flitted glass filter. The
filtrate was then degassed using an aspirator fitted with an
in-line drying tube. The solution was diluted to 10 mL with dry
CH.sub.2Cl.sub.2, placed under a nitrogen atmosphere and immersed
in an ice bath. 2-(Dimethylamino)ethanol (d=0.886 g/mL, 89.14
g/mol, 1.50 mmol), 133.5 mg, 151 .mu.L) was added drop wise (neat)
to the cold stirred solution. The ice bath was removed after 5 min.
and the mixture was allowed to stir overnight. The reaction flask
was again chilled in an ice bath and NEt.sub.3 (1 eq, 144 mg, 199
.mu.L) was added. The reaction was allowed to continue overnight.
The solvent was removed under reduced pressure, the crude residue
dissolved in CH.sub.2Cl.sub.2 and the solution applied to a silica
gel column with 96% CH.sub.2Cl.sub.2: 4% methanol as the moving
phase. The appropriate fractions were combined and concentrated to
an oil. This oil, the intermediate
4-[{2-(4-isobutylphenyl)propanoyloxy}methyl]phenyl
2-(dimethylammonium)ethyl carbonate, proved to be unstable
decomposing on standing to a fully water-soluble solid. Because of
its instability this intermediate was redissolved immediately in
ether (10 mL) and stirred vigorously while methyl iodide (500
.mu.L) was added. The mixture was stirred overnight, and the
product was collected by centrifugation at 10,000 G for 10 min. The
pellet was rinsed with fresh ether and centrifuged again. The ether
was drawn off, and the product dried under a stream of N.sub.2,
then under high vacuum. The yield was 123.9 mg or 22%.,
mp=106-110.degree. C. decomposition with gas evolution.
[0141] .sup.1H NMR (CD.sub.3CN): .delta. 7.42-7.40 (m, 2H,
meta-position on phenol), 7.30-7.29 (m, 2H, ortho to isobutyl
substituent), 7.19-7.17 (m, 2H, meta to isobutyl substituent),
7.03-7.01 (m, 2H, ortho-position on phenol), 5.16 (s, 2H,
Ar--CH.sub.2--O--CO--), 4.51-4.48 (m, 2H, --O--CH.sub.2CH.sub.2--),
3.989 (q, 1H, J=7.0 Hz, --CH(CH.sub.3)--CO--), 3.61-3.59 (m, 2H,
--CH.sub.2--N.sup.+Me.sub.3), 3.09 (s, 9H, --N(CH.sub.3).sub.3),
2.476 (d, 2H J=7.0 Hz, (CH.sub.3).sub.2CH--CH.sub.2--Ar), 1.862
(septet, 1H, J=7.0 Hz, (CH.sub.3)CH--CH.sub.2--), 1.533 (d, 3H,
J=7.0 Hz, --CH--CH.sub.3) and 0.886 (d, 6H, J=7.0 Hz,
(CH.sub.3).sub.2--CH--).
[0142] Mass spec. calcd. for C.sub.26H.sub.36NO.sub.5:
m/z=442.2593; observed, 442.2592.
Method D
[0143] Previous work from these laboratories has described the
synthesis of p-chloromethylphenyl carbonates which mimic a
choline-like recognition feature (ref). We have shown that under
some conditions a nucleophilic displacement by a carboxylate anion
can generate a satisfactory yield of the NSAID-releasing agents
revealed herein. An S.sub.N1-like pathway (carbonium ion promoted
by silver ion) was unsuccessful but an S.sub.N2-like pathway
(nucleophilic displacement mechanism) gave excellent yields. The
generation of a carboxylate anion under low-polarity, anhydrous
conditions with a toluene-soluble organic base makes this
displacement possible. The anhydrous base DBU used in generation of
carboxylic acid anions to promote S.sub.N2 reactions on alkyl
halides has been shown to extend to NSAIDs (N. Ono, T. Yamada, T.
Saito, K. Tanaka, and A. Kaji, Bull. Chem. Soc. Jpn. 1978, 51(8),
2401-2404).
Example 17
4-[{2-(2-Methoxynaphthalen-6-yl)propanoyloxy}methyl]phenyl
2-(trimethylsilyl)ethyl carbonate. Procedure for Reaction of Silver
Salt of Naproxen with 4-(Chloromethyl)phenyl
2-(Trimethylsilyl)ethyl Carbonate
##STR00033##
[0145] To 3.0 mL of DMF in which was dissolved 0.023 g (1.0 mmol)
of 2-(2-methoxynaphthalene-6-yl)propanoic acid (naproxen), was
added 0.017 g (1.0 mmol) of solid AgNO.sub.3. Gentle stirring for 4
hr at room temperature produced a solution. To this was added 0.029
g (1.0 mmol) of 4-(chloromethyl)phenyl 2-(trimethylsilyl)ethyl
carbonate in 0.5 mL of DMF. Stirring was continued for additional 5
hr during which time aliquots were drawn from reaction mixture,
added to water-ethyl acetate heterogeneous solution, and stirred
for 1 min. The ethyl acetate layer of each such aliquot was used
for TLC on silica gel plates which were conducted with a mobile
phase of 20% ethyl acetate: 80% hexane. Intense new spots were
observed at R.sub.f 0.85, 0.75, and 0.15 with only the faintest
hint (less than 5%) of authentic title product (R.sub.f=0.55). This
target compound was prepared in satisfactory yield by Method A (see
Example 10) but was clearly available only in trace amounts by this
variant of Method D.
Example 18
4-[{2-(2,6-Dichlorophenylamino)phenylethanoyl}methyl]phenyl
2-(Trimethylsilyl)ethyl Carbonate
##STR00034##
[0147] DBU (0.3 mmol, 0.05 g, 45 .mu.L) was added to a solution of
diclofenac (0.3 mmol, 0.09 g) in dry toluene (3 mL). The initially
cloudy solution became clear but a white solid began to precipitate
after 15 min of stirring at room temperature. To this was added
drop wise a second solution of 0.36 mmol, 0.10 g, of the benzyl
chloride analog in 3 mL of anhydrous toluene. The mixture was
refluxed for 5 hr under argon atmosphere. After 30 min of
refluxing, the solution turned yellow. Distilled water (20 mL) was
added to the oily reaction mixture and the organic phase was
extracted with methylene chloride (3.times.20 mL), washed with
water and dried over anhydrous magnesium sulfate. The solvent was
evaporated to yield crude yellow oil which was purified using
silica gel column chromatography with 80% hexane: 20% ethyl acetate
as the eluent to yield 0.10 g (61%) of clear oil product.
[0148] Clear oil, 61% yield, R.sub.f=0.58 (90% hexane: 10% ethyl
acetate).
[0149] .sup.1H NMR (500 MHz, CDCl.sub.3): .delta. 7.31 (d, 2H,
J=8.07 Hz), 7.23 (dd, 4H, J=8.62, 101 Hz), 7.21 (dd, 1H, J=1.43,
7.54 Hz), 7.11 (dt, 1H, J=7.56 Hz), 6.95 (m, 2H), 6.84 (bs, 1H),
6.53 (d, 1H, J=8.02 Hz), 5.14 (s, 2H), 4.32 (t, 2H, J=8.40 Hz),
3.83 (s, 2H), 1.12 (t, 2H, J=8.94 Hz), 0.05 (s, 9H).
General Procedure for Synthesis of the NSAID Esters (n=0; X.dbd.C,
Si) (Method E)
[0150] While inclusion of the p-hydroxybenzyl alcohol linker (for
those molecules in which n=1 in Formula 1 and as described in
Examples 7 to 18 herein) adds lipophilicity to the molecule and
provides two sites of hydrolytic scission, a simpler construct
where n=0 in Formula 1 also serves as a pro-drug controlled release
platform. Herein we describe molecules of that set (specific
examples 19 to 29).
##STR00035##
[0151] The appropriate NSAID (3.0 mmol), aliphatic alcohol (6 mmol)
and DMAP (0.30 mmol) were combined in dry CH.sub.2Cl.sub.2 (6 mL)
under nitrogen atmosphere. The solution was cooled to 0.degree. C.
and EDC (3.3 mmol) in CH.sub.2Cl.sub.2 (2 mL) was added. The
solution was slowly warmed up to room temperature and left stirring
overnight. Distilled water (80 mL) was added and the product was
extracted with CH.sub.2Cl.sub.2 (2.times.80 mL), washed with
saturated NaHCO.sub.3 and brine (160 mL each) and dried over
MgSO.sub.4. Products were purified by passing crude material
through a silica gel column using MeOH:CH.sub.2Cl.sub.2 (0.3-1.0%
MeOH) as the eluent.
Example 19
Preparation of 3,3-Dimethylbutyl
2-(1-(4-chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl)acetate
##STR00036##
[0153] Yellow oil, 96% yield; R.sub.f=0.68 (75% hexane:25% ethyl
acetate).
[0154] .sup.1H NMR (CDCl.sub.3): .delta. 0.89 (s, 9H), 1.51-1.55
(t, 2H, J=7.50 Hz), 2.36 (s, 3H), 3.63 (s, 2H), 3.82 (s, 3H),
4.12-4.16 (t, 2H, J=7.35 Hz), 6.63-6.66 (dd, 1H, J=2.55, 9.00 Hz),
6.83-6.86 (d, 1H, J=8.95 Hz), 6.93-6.95 (d, 1H, J=2.50 Hz),
7.44-7.46 (m, 2H), 7.62-7.65 (m, 2H).
[0155] Calc. for C.sub.25H.sub.28ClNO.sub.4 (441.95): C, 67.94; H,
6.39; N, 3.17. Found: C, 68.25; H, 6.48; N, 3.15.
Example 20
Preparation of (S)-3,3-Dimethylbutyl
2-(6-methoxynaphthalen-2-yl)propanoate
##STR00037##
[0157] White solid, 94% yield; MP=92-94.degree. C.; R.sub.f=0.75
(75% hexane:25% ethyl acetate).
[0158] .sup.1H NMR (CDCl.sub.3): .delta. 0.85 (s, 9H), 1.46-1.50
(t, 2H, J=7.45 Hz), 1.55 (d, 3H, J=7.15 Hz), 3.78-3.82 (m, 1H),
3.89 (s, 3H), 4.07-4.13 (m, 2H), 7.07-7.13 (m, 2H), 7.37-7.39 (dd,
1H, J=1.85, 8.45 Hz), 7.63-7.70 (m, 3H).
[0159] Calc. for C.sub.20H.sub.26O.sub.3 (314.42): C, 76.40; H,
8.33. Found: C, 76.74; H, 8.14.
Example 21
Preparation of 3,3-Dimethylbutyl
2-(2-(2,6-dichlorophenylamino)phenyl)acetate
##STR00038##
[0161] Clear oil, 55% yield; R.sub.f=0.83 (75% hexane:25% ethyl
acetate).
[0162] .sup.1H NMR (CDCl.sub.3): .delta. 0.90 (s, 9H), 1.56-1.60
(t, 2H, J=7.60 Hz), 3.77 (s, 2H), 4.16-4.20 (t, 2H, J=7.50 Hz),
6.52-6.54 (m, 1H), 6.91-6.98 (m, 3H), 7.08-7.12 (td, 1H, J=1.34,
7.18 Hz), 7.19-7.21 (m, 1H), 7.31-7.34 (d, 2H, J=8.05 Hz).
[0163] Calc. for C.sub.20H.sub.23NO.sub.2Cl (380.31): C, 63.16; H,
6.10; N, 3.68. Found: C, 63.24; H, 5.95; N, 3.74.
Example 22
Preparation of 3,3-Dimethylbutyl 2-(4-isobutylphenyl)propanoate
##STR00039##
[0165] Clear liquid, 83% yield; R.sub.f=0.95 (75% hexane: 25% ethyl
acetate).
[0166] .sup.1H NMR (CDCl.sub.3): .delta. 0.85 (s, 9H), 0.86-0.88
(d, 6H, J=6.60 Hz), 1.45-1.47 (d, 3H, J=4.95 Hz), 1.46-1.53 (m,
2H), 1.80-1.84 (m, 1H), 2.41-2.43 (d, 2H, J=7.20 Hz), 3.62-3.65 (m,
1H), 4.06-4.12 (m, 2H), 7.05-7.08 (d, 2H, J=8.10 Hz), 7.16-7.18 (d,
2H, J=8.05 Hz).
[0167] Calc. for C.sub.19H.sub.30O.sub.2 (290.44): C, 78.57; H,
10.41. Found: C, 78.06; H, 10.22. (For 0.1 mol H.sub.2O: C, 78.03;
H, 10.38).
Example 23
Preparation of 2-(Trimethylsilyl)ethyl
2-(1-(4-Chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl)acetate
##STR00040##
[0169] Yellow oil, 97% yield; R.sub.f=0.64 (75% hexane:25% ethyl
acetate).
[0170] .sup.1H NMR (CDCl.sub.3): .delta. 0.00 (9H), 0.94-0.99 (m,
2H), 2.36 (s, 3H), 3.62 (s, 2H), 3.82 (s, 3H), 4.15-4.19 (m, 2H),
6.63-6.66 (dd, 1H, J=2.55, 9.00 Hz), 6.83-6.86 (d, 1H, J=8.95 Hz),
6.94-6.95 (d, 1H, J=2.50 Hz), 7.43-7.47 (m, 2H), 7.63-7.66 (m,
2H).
[0171] Calc. for C.sub.24H.sub.28NO.sub.4ClSi (458.03): C, 62.94;
H, 6.16; N, 3.06. Found: C, 63.07; H, 6.19; N, 3.05.
Example 24
Preparation of 2-(Trimethylsilyl)ethyl
2-(2-(2,6-dichlorophenylamino)phenyl)acetate
##STR00041##
[0173] Clear oil, 79% yield; R.sub.f=0.94 (75% hexane:25% ethyl
acetate).
[0174] .sup.1H NMR (CDCl.sub.3): .delta. 0.00 (s, 9H), 0.96-1.00
(m, 2H), 3.74 (s, 2H), 4.17-4.19 (m, 2H), 6.49-6.51 (m, 1H),
6.88-6.96 (m, 3H), 7.05-7.09 (m, 1H), 7.17-7.19 (m, 1H), 7.29-7.31
(d, 2H, J=8.05 Hz).
[0175] Calc. for C.sub.19H.sub.23NO.sub.2Cl.sub.2Si (396.39): C,
57.57; H, 5.85; N, 3.53. Found: C, 57.73; H, 5.91; N, 3.51.
Example 25
Preparation of (S)-2-(Trimethylsilyl)ethyl
2-(6-methoxynaphthalen-2-yl)propanoate
##STR00042##
[0177] White solid, 80% yield; MP=81.5-82.5.degree. C.;
R.sub.f=0.90 (75% hexane:25% ethyl acetate).
[0178] .sup.1H NMR (CDCl.sub.3): .delta. 0.00 (s, 9H), 0.87-0.97
(m, 2H), 1.54-1.56 (d, 3H, J=7.20 Hz), 3.74-3.83 (m, 1H), 3.89 (s,
3H), 4.08-4.16 (m, 2H), 7.09-7.14 (m, 2H), 7.38-7.41 (dd, 1H,
J=1.65, 8.48 Hz), 7.64-7.70 (m, 3H).
[0179] Calc. for C.sub.19H.sub.26O.sub.3Si (330.50): C, 69.05; H,
7.93. Found: C, 69.18; H, 7.75.
Example 26
Preparation of 2-(Trimethylsilyl)ethyl
2-(4-isobutylphenyl)propanoate
##STR00043##
[0181] Clear liquid, 65% yield; R.sub.f=0.96 (75% hexane: 25% ethyl
acetate).
[0182] .sup.1H NMR (CDCl.sub.3): .delta. 0.00 (s, 9H), 0.86-0.90
(d, 6H, J=6.60 Hz), 0.88-0.96 (m, 2H), 1.44-1.47 (d, 3H, J=7.15
Hz), 1.79-1.85 (m, 1H), 2.41-2.43 (d, 2H, J=7.15 Hz), 3.61-3.66 (m,
1H), 4.06-4.16 (m, 2H), 7.05-7.08 (d, 2H, J=8.00 Hz), 7.16-7.19 (d,
2H, J=8.10 Hz).
[0183] Calc. for C.sub.18H.sub.30O.sub.2Si (306.52): C, 70.53; H,
9.86. Found: C, 70.53; H, 9.72.
General Procedure for Synthesis of the NSAID Esters (n=0;
X.dbd.N.sup.+ in Formula 1) (Method F)
Step 1--General Procedure for Preparation of N,N-Dimethylamino
Ethanol Lithium Salt
##STR00044##
[0185] Procedure derived from Schumann et al. Tetrahedron Lett.
2002, 43, 3507-3511. N,N-Dimethylaminoethanol (24 mmol, 2.40 mL)
was dissolved in dry hexane (17 mL) under nitrogen atmosphere. The
solution was cooled to 0.degree. C. and n-butyl lithium (24 mmol,
15.1 mL [1.6 M in n-hexane] was added dropwise. The solution was
slowly warmed up to room temperature and left stirring overnight.
The solvent was evaporated and the crude product was recrystallized
from hexane to yield yellow powder (1.35 g, 59%).
[0186] Procedures for following two synthetic steps were derived
from Venuti and Young Pharm. Res. 1989, 6, 867-873. (Procedure also
included in EU Patent 0,289,262, Feb. 11, 1988.) It should be noted
that all derivatives of this class (n=0, X.dbd.N.sup.+) are known
compounds.
Step 2--General Procedure for Preparation of NSAID
N,N-Dimethylaminoethyl Esters
##STR00045##
[0188] The appropriate NSAID (4 mmol) was suspended in dry
CH.sub.2Cl.sub.2 (15 mL). Triethylamine (4 mmol, 560 .mu.L) was
then added dropwise followed by 2-chloro-1-methyl-pyridinium iodide
(4 mmol, 1.02 g). The mixture was left stirring at room temperature
for 6 hr to allow for complete activation of the acid. The lithium
salt of N,N-dimethylaminoethanol (4 mmol, 0.40 g) was then added
and the resulting mixture was left stirring at room temperature for
2 days. 70 mL CH.sub.2Cl.sub.2 was added to the reaction mixture
and the organic phase was washed with distilled water several
times. A substantially pure product was isolated which was carried
onto the next step without further purification.
Step 3--Methylation of NSAID N,N-Dimethylaminoethyl Esters
##STR00046##
[0190] Methylation was carried out in an appropriate solvent
(CH.sub.2Cl.sub.2, acetone, THF or diethyl ether) using excess
CH.sub.3I (2 mL). The reaction was left stirring at room
temperature overnight. Upon return, if an observable precipitate
had not formed, an equal volume of ether was added and the pure
product precipitated out of solution. The precipitate was filtered
and washed with a small amount of cold ether.
Example 27
Preparation of
2-[[2-[1-(4-Chlorobenzoyl)-5-methoxy-2-methyl-1H-indol-3-yl]acetyl]oxy]-N-
,N,N-trimethyl-ethanaminium Iodide
##STR00047##
[0192] Yellow solid, 47% yield; MP=206-208.degree. C.
[0193] .sup.1H NMR (500 MHz, MeOD): .delta. 2.33 (s, 3H), 3.08 (s,
9H), 3.65-3.68 (m, 2H), 3.79 (s, 3H), 3.84 (s, 2H), 4.53-4.56 (m,
2H), 6.66-6.70 (dd, 1H, J=2.50, 9.05 Hz), 6.85-6.89 (d, 1H, J=9.00
Hz), 7.00-7.01 (d, 1H, J=2.50 Hz), 7.54-7.58 (m, 2H), 7.64-7.67 (m,
2H).
[0194] Calc. for C.sub.24H.sub.28N.sub.2O.sub.4ClI (570.85): C,
50.50; H, 4.94; N, 4.91. Found: C, 49.92; H, 4.93; N, 4.87. (with
0.15 mol H.sub.2O: C, 50.25; H, 4.97; N, 4.88).
Example 28
Preparation of
2-[2-(6-Methoxy-2-naphthalenyl)-1-oxopropoxy]-N,N,N-trimethyl-ethanaminiu-
m Iodide
##STR00048##
[0196] White solid, 44% yield; MP=202-204.degree. C.
[0197] .sup.1H NMR (500 MHz, MeOD): .delta. 1.55-1.57 (d, 3H,
J=7.15 Hz), 2.93 (s, 9H), 3.3.50-3.67 (m, 2H), 3.88 (s, 3H),
3.90-3.97 (m, 1H), 4.40-4.60 (m, 2H), 7.10-7.13 (dd, 1H, J=2.50,
8.93 Hz), 7.19-7.20 (d, 1H, J=2.45 Hz), 7.35-7.39 (dd, 1H, J=1.85,
8.50 Hz), 7.68-7.75 (m, 3H).
[0198] Calc. for C.sub.19H.sub.26NO.sub.3I (443.32): C, 51.48; H,
5.91; N, 3.16. Found: C, 51.54; H, 5.96; N, 3.07.
Example 29
Preparation of
N,N,N-Trimethyl-2-[2-[4-(2-methylpropyl)phenyl]-1-oxopropoxy]-ethanaminiu-
m Iodide
##STR00049##
[0200] White solid, 18% yield; MP=113-114.degree. C.
[0201] .sup.1H NMR (MeOD): .delta. 0.86-0.88 (d, 6H, J=5.10 Hz),
1.45-1.49 (d, 3H, J=7.15 Hz), 1.78-1.83 (m, 1H), 2.42-2.44 (d, 2H,
J=7.15 Hz), 3.00 (s, 9H), 3.55-3.83 (m, 2H), 4.08 (s, 1H),
4.37-4.56 (m, 2H), 7.09-7.12 (m, 2H), 7.18-7.23 (m, 2H).
[0202] Calc. for C.sub.18H.sub.30NO.sub.2I (419.34): C, 51.56; H,
7.21; N, 3.34. Found: C, 49.41; H, 7.09; N, 3.59. (with 0.75 mol
H.sub.2O: C, 49.94; H, 7.33; N, 3.24).
AChE inhibition: Experimental
[0203] Acetyl cholinesterase Inhibition Methodology
[0204] Acetyl cholinesterase (Type V-S from Electrophorus
electricus), acetyl thiocholine iodide (ACM),
5,5'-dithiobis(2-nitrobenzoic acid) (DTNB) and tacrine
hydrochloride were obtained from Sigma-Aldrich (Saint Louis, Mo.).
Methanol for the preparation of stock solutions was obtained from
EMD Chemicals. Cholinesterase inhibition was assayed
spectrophotometrically at 412 nm according to the method of Ellman
(Biochem. Phamacol. 1961, 7: 88-95). Assays were performed in
polystyrene 96-well plates (Corning 96-well flat transparent) and a
conventional micro-plate reader was employed (Tecan's Infinite 200
multimode). The assay procedures were as follow: 200 .mu.L of 0.5
mM DTNB in 100 mM sodium phosphate buffer (pH 8), 30 .mu.L of
inhibitor stock solution prepared in methanol, 50 .mu.L of 3 mM
AChI and 20 .mu.L of 1.25 u/mL AChE prepared respectively in
phosphate buffer 100 mM pH 8 and 20 mM pH 7. Immediately after the
enzyme was added the signal was measured at 30 s intervals over 5
min at 25.degree. C. Percentage inhibition was calculated relative
to a control sample (methanol). The background signal was measured
in control wells containing all the reagents except AChE. IC.sub.50
values were obtained from a minimum of eight concentrations in
duplicate and by fitting the experimental data with a dose-response
curve using a curve fitting software (Prism Version 5.00, GraphPad
Software, San Diego, Calif.). IC.sub.50 values from 0.51 to 2.29
.mu.M were measured for the NSAID ester-carbonates of the
trimethylsilyl and the t-butyl choline analogs (viz Examples 7-15)
and of 77.7 .mu.M for the true choline species (Example 16). The
best inhibitor in the NSAID ester-carbonate set (see Table 1) has
an IC.sub.50 only ten-times higher than that of the clinical
standard AChE inhibitor, tacrine hydrochloride. The NSAID esters
(examples 19-29) inhibited AChE on the micromolar to milimolar
scale (see Table 2), they were found less active than their
ester-carbonate analog (i.e., the molecules containing the
p-functionalized benzyl alcohol, examples 7-18) by at least a
factor of 4. The most potent NSAID ester (Example 24) inhibited
AChE at 2.66 .mu.M, a value within the range of other known
inhibitors. As in the ester-carbonate series, the true choline
analogues (i.e., those with N.sup.+) of the NSAID ester series
(Examples 27, 28 and 29) were less potent inhibitors with IC.sub.50
values ranging from 0.23 to 3.4 mM.
Acetylcholinesterase Inactivation and Reactivation
[0205] Inactivated enzyme was obtained by incubating 20 units of
enzyme in 1 mL phosphate buffer (20 mM, pH 7) with 55 .mu.L of the
inhibitor. Stock solution of inhibitors were prepared in methanol
and the final concentration of inhibitor was 52 .mu.M. A control
incubation (methanol) was run with the enzyme in absence of the
inhibitor. After 30 minutes of incubation at 25.degree. C., an
aliquot of 500 .mu.L was applied to a standardized Sephadex G-25
Medium (PD MiniTrap.TM.) and eluted with 100 mM sodium phosphate
buffer (pH 7) containing 0.1% triton 100.times. in order to
maintain enzyme activity. Protein content was assayed using a micro
BCA Protein Assay kit (ThermoScientific). Recovery of enzyme
activity suggesting reversible inhibition was demonstrated by the
Ellman's method previously described (results shown in Table
3).
Kinetic Inhibition Studies
[0206] To determine the type of inhibition of AChE, kinetic
inhibition studies were performed and the results plotted by the
Lineweaver-Burk method (H. U. Bergmeyer and K. Gawehn, "Principles
of Enzymatic Analysis," Verlag Chemie, NY, 1978, pp. 36-40). The
kinetics were generated by using a fixed amount of enzyme (0.025
units) and varying both amounts of substrate (1000 to 50 .mu.M
final concentrations) and inhibitor (1 to 100 .mu.M final
concentration). Experiments were carried out in duplicate or
triplicate with the analysis performed by the Ellman method
previously described. FIG. 2 displays the results from Example 9
and Example 22.
[0207] Single or multiple intersection points located in quadrant
III or abscissa of the five double-reciprocal rate lines marks
these reactions as reversible non-competitive inhibition (V.
Leskovac, "Comprehensive Enzyme Kinetics", Kluwer Academic/Plenum
Publishers, NY, 2003, pp. 99-102). This precise type
non-competitive inhibition has also been observed in other AChE
inhibitor families including decamethonium and the semi-synthetic
steroidal alkaloids from Buxus balearica. (T. Sauvaitre, M.
Barlier, D. Herlem et al., J. Med. Chem. 2007, 50: 5311-5323).
Similar behavior was observed for other NSAID ester and
ester-carbonate pro-drugs. These findings reinforce the claim of
reversibility supported by the recovery of enzyme activity from
inhibited enzyme following Sephadex chromatography.
Chemical Hydrolysis Studies
[0208] Hydrolysis of the inhibitors was carried out at 37.degree.
C. under constant stirring. Pro-drug was added to an aqueous
potassium carbonate (10 eq) solution containing 20% DMSO v/v for a
final concentration in prodrug of 0.5 mg/mL. Aliquots of the
reaction were withdrawn periodically and diluted by 2 with
acetonitrile prior HPLC analysis. Samples were injected onto a C18
reverse phase column (Agilent Eclipse C18 4.6.times.150 mm,
35.degree. C., 20 .mu.L injection, UV detection at 230 and 267 nm,
flow rate 0.5 ml/min, post time 5 min). A gradient method was run
with mobile phase A: 0.1% TFA in water and B: Acetonitrile, method
0 to 2 minutes: 80% A, 2 to 15 minutes: 80% to 15%, 15 to 25: 15%,
25 to 30 minutes: 15% to 80%. Authentic standards of the parent
pro-drugs, the NSAID, and the 4-hydroxybenzyl alcohol were obtained
and used for comparison. For a typical chromatograph obtained with
the pro-drug Example 9 and after 2 hr see FIG. 1. The release of
both the NSAID Naproxen and the 4-hydroxybenzylalcohol suggested
both cleavages at the ester and carbonate bond.
Aqueous Hydrolysis Studies
[0209] Hydrolysis rates in aqueous solution were determined in
saline phosphate buffer (PBS, pH 7.4). Methanol (up to 50%) was
used as a co-solvent to effect solution and to prevent
precipitation over time. After vortexing, pro-drug solutions
(.about.50-75 .mu.M) were incubated at 37.degree. C. At regular
intervals, samples of the reaction mixture were withdrawn, diluted
by two with acetonitrile and analyzed by HPLC (see description
below). Remaining pro-drug and NSAID released were monitored by
single determination. Half-life times (hr) in aqueous solutions
were determined by plotting the semi-log of either pro-drug
disappearance or of drug released (FIG. 3). Half-life values for
several example molecules are included in Table 4. Hydrolysis of
the parent drug and subsequent release of the NSAID was observed
under physiological pH 7.4. HPLC method--Agilent Eclipse XDB-C18
column (5 .mu.m, 4.6.times.150 mm); mobile phase: water (A) and
acetonitrile (B) containing 0.1% TFA; flow rate: 1.5 mL/min;
gradient increase from A/B:80/20 to 30/70 over 10 min, to 10/90
over 15 min, return to initial condition in 5 min, post-time run 5
min; injection: 25 .mu.L detector wavelength 210 nm.
Plasma Hydrolysis Studies
[0210] The rate of hydrolysis for pro-drugs was determined at
37.degree. C. in fresh human plasma diluted to 80% with PBS (pH
7.4). Human plasma was obtained from the pooled, heparininised
blood of healthy donors and was frozen and stored at -80.degree. C.
prior to use. Test compounds (20 .mu.L, 1 mM in DMSO) were added to
pre-heated plasma (960 .mu.L) and mixed gently at 300 rpm. DMSO
reached 2% volume content. At suitable intervals, aliquots of 100
.mu.L were withdrawn and 200 .mu.L of cold precipitation buffer
(90/10 acetonitrile/water with 0.1% formic acid) were added to
precipitate proteins from the serum. The resulting mixture was
filtered through a Mini-Uniprep.TM. filter (Whatman, PVDF membrane,
0.45 .mu.m) and the filtrate was analyzed by HPLC (, see
description below). Remaining pro-drug and NSAID released was
monitored by single determination at 230 or 277 nm. Half-life times
for example compounds in plasma are shown in Table 4. All prodrugs
tested show NSAID-release with half-lives not exceeding 8 hr. For a
typical chromatograph obtained with Example 14 after 12.5 hr
incubation see FIG. 3. HPLC method--Agilent high resolution XDB-C18
column (1.8 .mu.m, 4.6.times.50 mm); mobile phase: water (A) and
methanol (B) containing 0.1% formic acid; flow rate: 0.8 mL/min;
gradient increase from A/B:70/30 to 30/70 over 8 min, 30/70 to
10/90 over 4 min, 10/90 to 5/95 over 4 min, 5/95 to 70/30 over 4
min, post-time 5 min; injection: 25 .mu.L; UV detection 230 and 277
nm.
TABLE-US-00001 TABLE 1 Anticholinesterase activity of NSAID
carbonates (n = 1, X = C, Si, N.sup.+). NSAID series Example # X
IC.sub.50 (.mu.M) Ibuprofen 7 C 1.93 .+-. 0.64 8 Si 1.19 .+-. 0.20
16 N.sup.+ 77.7 .+-. 0.8 Naproxen 9 C 1.74 .+-. 1.01 10 Si 0.83
.+-. 0.15 Indomethacin 12 C 2.29 .+-. 0.94 13 Si 0.72 .+-. 0.13
Diclofenac 14 C 0.51 .+-. 0.02 15 Si 1.36 .+-. 0.13 Reference
Tacrine HCl -- 0.055* .+-. 0.005 *Literature value for tacrine HCl
IC.sub.50 0.039 .mu.M (J. Med. Chem. 2001, 44, 2707-2718).
TABLE-US-00002 TABLE 2 Anticholinesterase activity of NSAID esters
(n = 0, X = C, Si, N.sup.+). NSAID Series Example # X IC.sub.50
(.mu.M) Ibuprofen 22 C 24.57 .+-. 14.5 26 Si 25.67 .+-. 4.85 29
N.sup.+ 3376 .+-. 2650 Naproxen 20 C 19.65 .+-. 1.70 25 Si 13.88
.+-. 0.26 28 N.sup.+ 907.4 .+-. 387 Indomethacin 19 C 9.75 .+-.
0.89 23 Si 3.32 .+-. 0.36 27 N.sup.+ 230.3 .+-. 32.3 Diclofenac 21
C 2.69 .+-. 0.15 24 Si 2.66 .+-. 0.25
TABLE-US-00003 TABLE 3 AChE Activity Recovery After Inactivation
Inhibitor % Enzyme Activity.sup.a none.sup.b 100 Example 7 109
Example 9 95 Example 14 95 Example 21 95 Example 20 113 Tacrine HCl
95 .sup.aEnzyme activity was assayed after 30 min incubation with
52 .mu.M inhibitor which deactivated the enzyme. Subsequent
chromatography over Sephadex gel resulted in near-complete
restoration of activity. .sup.bControl without inhibitor
present.
TABLE-US-00004 TABLE 4 Half-Lives of NSAID Prodrugs in PBS and
Plasma at 37.degree. C. Example # t.sub.1/2 (hr).sup.a t.sub.1/2
(hr).sup.b 7 20.4 3.33 9 nd 2.23 12 nd 7.80 14 6.95 5.93 21 105 nd
.sup.aIn PBS (pH 7.4) Buffer. .sup.bIn diluted human plasma. nd:
Half-life not determined.
Anti-Inflammatory Results
Experimental Method
[0211] The mouse ear vesicant model (MEVM) was used to assess the
anti-inflammatory activity of dual action therapeutics. In this
assay, sulfur mustard or a sulfur mustard analog is applied
topically to the ears of female CD-1 mice (24-25 days old) in 20
.mu.L of dichloromethane or acetone to generate an inflammatory
response. This is evident by the appearance of edema in the mouse
ears. Edema was measured by increases in the wet weight of ear
punch biopsies. Control mice received dichloromethane or acetone
without the mustard. To evaluate drugs, ears were pretreated with
20 .mu.L of vehicle control (dichloromethane or acetone) or 20
.mu.L of test compounds 20 min prior to treatment with the sulfur
mustard. For our studies, 2-chloroethyl ethyl sulfide, a model
sulfur mustard vesicant was used. Then, five hr later, all mice
were sacrificed. The ear punches (6 mm in diameter) were taken and
weighed. Data was analyzed as percent inhibition of
vesicant-induced edema.
[0212] As an alternative, the TPA
(12-O-tetradecanoylphorbol-13-acetate)-induced ear edema assay was
carried out to examine anti-inflammatory activity of dual
functional therapeutics in a skin inflammation model. The female
CD-1 mice (24-25 days old) were topically treated with 20 .mu.l, of
acetone or dual functional therapeutic in 20 .mu.L of acetone at 20
min before topical application of 20 .mu.L of acetone or TPA (1
nmol) in 20 .mu.L of acetone. Then, five hr later, all mice were
sacrificed and ear punches (6 mm in diameter) were taken and
weighed.
Results
[0213] Comparable results were observed from either inflammatory
challenge method and Table 5 displays sample findings. Suppression
percentages varied from 38 to 95% across the set of compounds.
TABLE-US-00005 TABLE 5 Anti-Inflammatory Results from MEVM Example
# Suppression of CEES 7 52% 12 54% 13 85% 14 93% 25 55% 26 50% 29
38%
ABBREVIATIONS
[0214] AChE acetylcholine esterase AChI acetylthiocholine iodide
CDI 1,1'-carbonyldiimidazole DBU 1,8-diazabicyclo[5.4.0]undec-7-ene
DCC dicyclohexylcarbodiimide DIAD diisopropyl azodicarboxylate DMAP
4-(dimethylamino)pyridine
DMF N,N-dimethylformamide
[0215] DTNB 5,5'-dithiobis(2-nitrobenzoic acid) EDC,
1-[3-(dimethylamino)propyl]-3-ethylcarbodimide methiodide NSAID
non-steroidal anti-inflammatory agent MEVM mouse ear vesicant model
PVP polyvinylpyridine R.sub.f Retention factor; ratio of distance
migrated on TLC by a compound over the [0216] distance to the
solvent front RPM revolutions per minute THF tetrahydrofuran TLC
thin layer chromatography on silica coated glass plates TPA
12-O-tetradecanoylphorbol-13-acetate TPP triphenylphosphine
* * * * *