U.S. patent number 3,903,071 [Application Number 05/362,700] was granted by the patent office on 1975-09-02 for mycophenolic acid derivatives.
This patent grant is currently assigned to Eli Lilly and Company. Invention is credited to Richard E. Holmes.
United States Patent |
3,903,071 |
Holmes |
September 2, 1975 |
Mycophenolic acid derivatives
Abstract
Mycophenolic acid aldose derivatives which are useful in
affecting the growth of transplanted tumor cells in mice and rats,
and in the treatment of psoriasis and gout, and intermediates
useful in the preparation thereof.
Inventors: |
Holmes; Richard E.
(Indianapolis, IN) |
Assignee: |
Eli Lilly and Company
(Indianapolis, IN)
|
Family
ID: |
23427173 |
Appl.
No.: |
05/362,700 |
Filed: |
May 22, 1973 |
Current U.S.
Class: |
536/18.1;
514/863 |
Current CPC
Class: |
C07H
17/04 (20130101); Y10S 514/863 (20130101) |
Current International
Class: |
C07H
17/04 (20060101); C07H 17/00 (20060101); C07H
009/00 () |
Field of
Search: |
;260/21R,21AB |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Brown; Johnnie R.
Attorney, Agent or Firm: Harrison; Nancy J. Page; Kathleen
R. S. Smith; Everet F.
Claims
I claim:
1. A compound of the formula: ##EQU2## wherein R represents OH,
loweralkoxy of 1 to 5 carbon atoms, or amido; and R' represents
a. .beta.-D-glucopyranosyl,
b. .beta.-D-galactopyranosyl,
c. .beta.-D-allopyranosyl,
d. .beta.-D-gulopyranosyl,
e. .beta.-D-ribofuranosyl,
f. .beta.-D-ribopyranosyl, or
g. .beta.-D-xylopyranosyl;
or, when R is loweralkoxy as defined, R' can additionally represent
any of the (a) through (g) moieties peracylated with C.sub.2
-C.sub.4 -alkanoyl or benzoyl;
and the pharmaceutically acceptable, alkali-metal or
alkaline-earth-metal salts derived from those compounds wherein R
is OH.
2. A compound of claim 1 wherein R' represents (a) through (g).
3. A compound of claim 2 wherein R' is .beta.-D-glucopyranosyl.
4. The compound of claim 3 which is ethyl
6-[4-(.beta.-D-glucopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-me
thyl-4-hexenoate.
5. The compound of claim 3 which is methyl
6-[4-(.beta.-D-glucopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-me
thyl-4-hexenoate.
6. The compound of claim 3 which is
6-[4-(.beta.-D-glucopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-me
thyl-4-hexenoic acid.
7. A compound of claim 2 wherein R' is
.beta.-D-galactopyranosyl.
8. A compound of claim 1 wherein R is loweralkoxy and R' is any of
the (a) through (g) moieties peracylated with C.sub.2 -C.sub.4
-alkanoyl or benzoyl.
Description
BACKGROUND OF THE INVENTION
Psoriasis is a common chronic skin disease of undetermined cause.
Characteristic features of psoriasis are persistent patches of
redness covered with scales. The disease is in part determined by a
genetically dominant trait. While it is absent at birth, it can
begin at any age from childhood to extreme old age. Psoriasis does
not, however, appear to be a communicable disease; there are no
known causative factors for it in the environment.
In the involved patches, the cells of the epidermis grow and
multiply up to seven times faster than do normal epidermis
cells.
No known therapeutic method assures a cure. Agents currently used
in the treatment of psoriasis include ultraviolet light, coal tar,
ammoniated mercury, anthralin, and topical corticosteroids.
Methotrexate has been used to treat psoriasis by systemic
administration, but such treatment method is accompanied by severe
side effects. Antimetabolite drugs such as aminopterin,
thioguanine, and azaribine have also been used in treating this
disease.
Although psoriasis seldom affects the general health of the
patient, the disease can be debilitating. Psychlogical effects,
secondary infections, itching and arthritic manifestations are
among the troublesome symptoms encountered. There is, therefore, a
continuing need for improved agents in the treatment of this
disease.
Another frequently debilitating disease is gout. Gout is caused by
uric acid crystal deposits in tissues, particularly in the
cartilage of joints, bone and kidney. These uric acid crystal
deposits are a result of an increase in circulating uric acid, a
condition known as hyperuricemia. The therapeutic agents currently
used in the treatment of hyperuricemia are generally accompanied by
undesirable side effects, such as gastrointestinal spasm,
bone-marrow depression, and skin reactions. Improved agents which
reduce serum uric acid levels without causing undesirable side
effects are, therefore, in demand.
Mycophenolic acid, from which the compounds of the present
invention are prepared, is a well-known natural product. First
isolated in 1896, mycophenolic acid is known to exhibit antifungal,
antibacterial, antiviral, and antitumor properties [see U.S. Pat.
No. 3,705,894; French Pat. No. 2,010,136; South African Pat. No.
6,903,147 (Derwent No. 28275R)]. Mycophenolic acid is also useful
in the treatment of psoriasis and hyperuricemia [see U.S. Pat. No.
3,705,946; Netherlands Pat. No. 7,116,238 (Derwent No. 37140T)].
Mycophenolic acid glucuronide, the natural metabolite of
mycophenolic acid, has also been reported to have antitumor
activity [see French Pat. No. 2,100,653 (Derwent No. 41305T); J.
Antibiotics 23 (8) 408-413 (1970)].
SUMMARY OF THE INVENTION
The present invention is directed to novel mycophenolic acid
derivatives having the following formula: ##EQU1## wherein R
represents OH, loweralkoxy of 1 to 5 carbon atoms, or amido; and R'
represents
A. .beta.-D-glucopyranosyl,
b. .beta.-D-galactopyranosyl,
c. .beta.-D-allopyranosyl,
d. .beta.-D-gulopyranosyl,
e. .beta.-D-ribofuranosyl,
f. .beta.-D-ribopyranosyl, or
g. .beta.-D-xylopyranosyl;
or, when R is loweralkoxy as defined, R' can additionally represent
any of the (a) through (g) moieties peracylated with C.sub.2
-C.sub.4 -alkanoyl or benzoyl;
and the pharmaceutically-acceptable, alkali-metal or
alkaline-earth-metal salts derived from those compounds wherein R
is OH.
The compounds of Formula I wherein R' represents (a) through (g)
are useful in affecting the growth of transplanted tumor cells in
mice and rats, and in the treatment of psoriasis and gout. The
compounds of Formula I wherein R' represents a peracylated (a)
through (g) moiety as defined are useful intermediates.
DETAILED DESCRIPTION OF THE INVENTION
The scope of compounds in accordance with the present invention is
as defined hereinabove. In the moieties defined herein as
loweralkoxy, the alkyl portion can be a straight- or branched-chain
alkyl group. In the intermediate compounds, peracylation refers to
complete acylation of hydroxyl groups in the respective R'
moiety.
In the case of salts, an alkali-metal or alkaline-earth metal may
be chosen to form a salt with special advantages, such as ready
solubility, ease of crystallization and the like; but in any event,
the salt formed must be pharmaceutically acceptable. Representative
and suitable salts include the sodium, potassium, lithium,
magnesium and calcium salts.
The compounds of the present invention are not readily prepared by
conventional methods for the formation of glycosides. For example,
the Koenigs-Knorr synthetic method (H. Krauch and W. Kunz, "Organic
Name Reactions," John Wiley and Sons, New York, N.Y., 1964, p. 314)
was used to prepare the naturally-occurring .beta.-D-glucuronide
metabolite [K. Ando, S. Suzuki, and M. Arita, J. Antibiotics 23
(8), 408-413 (1970)]. The Koenigs-Knorr method waw not found to be
useful, however, in the preparation of the novel compounds of the
present invention.
The compounds of the present invention are prepared by reacting a
per-O-acylglycosyl halide with a mycophenolic acid ester in the
presence of a non-nucleophilic base.
The mycophenolic acid ester derivatives useful in the preparation
of the present compounds are known in the art [see, for example, J.
Med. Chem. 14, 305 (1971)].
The appropriate per-O-acylglycosyl halides used to prepare the
compounds of the present invention are also known in the art. For a
review of the chemistry of these compounds, see Advan. Carbohyd.
Chem. 10, 207-256 (1955). The per-O-acetylglycosyl halides are most
frequently used. However, other acylglycosyl halides, for example,
the other per-(C.sub.2 -C.sub.4 -alkanoyl)glycosyl halides and the
per-O-benzoylglycosyl halides, are also useful. Of the various
useful halides, the bromides and chlorides are most commonly
employed, since iodides decompose easily and fluorides are less
reactive.
Non-nucleophilic bases, such as hindered amines or quinoline, which
do not interact with the per-O-acylglycosyl halide but which do
take up the liberated hydrogen halide, are suitable for use in the
reaction.
Good results are typically achieved with this reaction when the
number of moles of per-O-acylglycosyl halide is either equivalent
to or up to about three times the number of moles of mycophenolic
ester used.
Conveniently, the reaction is carried out in the presence of a
polar aprotic solvent such as, for example, dimethylformamide. The
reactants are heated to temperatures in the range of about
50.degree. to about 100.degree.C. and preferably in the range of
about 75.degree. to about 80.degree.C. Under these conditions, the
reaction is usually complete in about 25 to about 48 hours.
In a typical workup, the amine hydrohalide formed during the course
of the above-described reaction is separated by precipitation in a
solvent such as xylene or toluene, cooling for several hours.
Xylene is especially suitable because it forms a
conveniently-removed azeotrope with dimethylformamide.
The filtrate from the above-described precipitation is evaporated
under vacuum, and the residue is dissolved in a solvent such as,
for example, diethyl ether. If necessary, undissolved solids are
again separated, and the ether filtrate is evaporated under vacuum
to give compounds of Formula I wherein R' is a peracylated (a)
through (g) moiety. In general, these compounds are useful as
intermediates without further purification at this point.
The acyl groups of the R' moiety are cleaved by treatment with
base. A saturated solution of ammonia in alcohol is generally
useful for deacylating the sugar moiety without affecting the ester
function of the mycophenolic acid moiety.
The reaction mixture resulting from the deacylation step is treated
further to remove excess per-O-acylglycosyl halide. In a preferred
manner, the solvent is removed, and the residue is dissolved in
water. This solution is extracted with an organic solvent, such as
chloroform. The unreacted per-O-acylglycosyl halide is separated in
the aqueous phase to give in the organic phase a compound of
Formula I wherein R is alkoxy. The compound is separated and
characterized by well-known procedures. From this alkoxy
derivative, other corresponding Formula I alkoxy derivatives are
conveniently prepared by routine ester-exchange techniques.
The compounds of Formula I wherein R is OH are prepared by standard
procedures for hydrolysis and cleavage of esters [see J. Amer.
Chem. Soc. 55, 4079 (1933)] from the corresponding esters obtained
as described hereinabove.
The compounds of Formula I wherein R is OH can be further reacted
to obtain the corresponding, specified alkali-metal and
alkaline-earth-metal salts. In such further reaction the
above-mentioned acid is reacted slowly with a stoichiometric amount
of a suitable base, generally without heating, to obtain the
corresponding salt. These reactions are of a type well known in the
art, and the particular steps employed to prepare such salts are
carried out in accordance with these well-known procedures.
The compounds of Formula I wherein R is NH.sub.2 are prepared by
reacting the corresponding compound wherein R is alkoxy, especially
those wherein R is methoxy, with ammonia in methanol for about
three days or more. The product is recovered by standard
procedures.
Those compounds of Formula I wherein R' is .beta.-D-glucopyranosyl
or tetraacetyl-.beta.-D-glucopyranosyl are preferred compounds. The
starting tetra-O-acetyl-.alpha.-D-glucosyl halide used in the
preparation of these compounds is more readily available and, in
addition, is less expensive. Thus, the resulting Formula I
glucopyranosides are superior, having the advantages of greater
availability and lowered cost.
The novel compounds of Formula I wherein R' represents (a) through
(g) are useful in affecting the growth of transplanted tumor cells
in mice and rats.
Standardized procedures were used to test various of the Formula I
compounds. These procedures are described by I. S. Johnson et al.
in Cancer Res. 20, 1016 (1960). More recently, M. J. Sweeney et al.
evaluated the antitumor activity of mycophenolic acid by these
methods [see Cancer Res. 32, 1795 (1972)].
METHOD
Solid tumor fragments are implanted subcutaneously by trocar in the
axillary region of mice and rats. Animals receive daily
intraperitoneal doses of test compounds for seven to ten days after
implantation. Control groups of tumor-bearing mice or rats receive
daily doses of vehicle only. Therapy against the rapidly growing
tumors begins 24 hours after implantation. Treatment of X5563
plasma cell myeloma is delayed for 3 to 5 days after implantation.
The inhibition of tumor growth is determined by comparing the
average tumor diameter of the treated group (T) with that of the
control group (C) and expressing the result as percentage
inhibition.
Leukemias are initiated by an intraperitoneal injection of a cell
suspension of spleen homogenate. Beginning 24 hours after
inoculation and continuing for 8 to 10 days, test compounds are
administered by intraperitoneal injection. Response is determined
by comparing the average life-span of the treated groups (T) with
that of control groups (C), and activity is expressed as percentage
prolongation of life.
The following abbreviations are used to describe the tumor systems
tested:
Host.sup.a ______________________________________ MLS Mecca
lymphosarcoma AKR Ca-755 Adenocarcinoma 755 C57BL/6 GLS Gardner
lymphosarcoma C3H L1210 L1210 lymphocytic leukemia DBA/2 Walker 256
Walker carcinosarcoma 256 SD.sup.b rat X5563 X5563 plasma cell
myeloma C3H S-91 S-91 melanoma DBA/1
______________________________________ .sup.a Mouse strain
designations conform to the listing of The Committee on
Standardized Genetic Nomenclature for Mice (Staats, J.
"Standardized Nomenclature for Inbred Strains of Mice: Fourth
Listing" Cancer Res. 28: 391-420 (1968) .sup.b Sprague-Dawley
Table I illustrates the usefulness of the compounds defined above
as antitumor agents against Mecca lymphosarcoma.
TABLE I ______________________________________ Antitumor Activity
Against Mecca Lymphosarcoma Formula I Compound Dose.sup.a Av. Tumor
Inhibi- (mg/kg .times. Diameter tion of R' R' no. days) T/C (mm)
Tumor Growth ______________________________________ .beta.-D-gluco-
OC.sub.2 H.sub.5 100 .times. 7 12.2/23.5 48 pyranosyl
.beta.-D-gluco- OC.sub.2 H.sub.5 100 .times. 7 0/16.1 100 pyranosyl
.beta.-D-gluco- OC.sub.2 H.sub.5 150 .times. 9 9.6/26.4 64
pyranosyl .beta.-D-gluco- OC.sub.2 H.sub.5 150 .times. 7 0/16.1 100
pyranosyl .beta.-D-gluco- OCH.sub.3 145 .times. 9 8.4/26.4 68
pyranosyl .beta.-D-gluco- OCH.sub.3 150 .times. 8 14.2/24.4 42
pyranosyl .beta.-D-galacto- OC.sub.2 H.sub.5 100 .times. 7
16.7/23.5 29 pyranosyl ______________________________________
.sup.a Doses were given once daily for the specified number of
days.
Table II illustrates the usefulness of various Formula I compounds
wherein R' is .beta.-D-glucopyranosyl against a variety of tumor
systems.
TABLE II ______________________________________ Comparison of
Antitumor Activities Dose.sup.a Av. Tumor % (mg/kg Diameter
Inhibition R System .times. days) T/C (mm) of Growth
______________________________________ OCH.sub.3 Ca-755 145 .times.
9 9.3/18.2 49 OC.sub.2 H.sub.5 Ca-755 150 .times. 9 10.3/18.2 44
OC.sub.2 H.sub.5 Ca-755 100 .times. 3) 10.7/20.8 49 150 .times. 7)
OCH.sub.3 GLS 145 .times. 9 17.9/29.4 39 OC.sub.2 H.sub.5 GLS 150
.times. 9 15.6/29.4 47 OCH.sub.3 Walker 150 .times. 8 0/27.0 100
256 OCH.sub.3 S-91 150 .times. 8 13.5/15.8 15 OCH.sub.3 X5563 150
.times. 8 12.1/17.6 31 OC.sub.2 H.sub.5 X5563 100 .times. 3)
12.2/17.2 29 150 .times. 7) ______________________________________
.sup.a Doses were given once daily for the specified number of
days.
Table III further illustrates the antitumor activity of two Formula
I compounds wherein R' is .beta.-D-glucopyranosyl against two
leukemia systems.
TABLE III ______________________________________ Comparison of
Antileukemic Activities Dose (mg/kg .times. Av. Life Prolongation R
System days) T/C of Life ______________________________________
OCH.sub.3 C1498 150 .times. 10 19.1/14.5 32 OC.sub.2 H.sub.5 L1210
150 .times. 10 18.0/15.4 16
______________________________________
When used as antitumor agents, in mice and rats the compounds of
Formula I wherein R' represents (a) thorugh (g) may be administered
either orally or parenterally. Although the dosage administered
will vary according to factors such as the tumor system involved,
the compound being used, the severity of the disease and the like,
the above-specified Formula I compounds are typically effective as
antitumor agents when given in the range of about 40 mg/kg to about
300 mg/kg.
It is known that mycophenolic acid is converted in vivo to its less
toxic glucuronide derivative. In the novel compounds of this
invention, a carbohydrate moiety blocks the phenolic group of
mycophenolic acid and thereby blocks such glucuronide formation.
Initial studies of bile and urine from animals receiving a typical
Formula I compound, methyl
6-[4-(.beta.-D-glucopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-me
thyl-4-hexenoate, did not reveal a detectable amount of either
mycophenolic acid or mycophenolic acid glucuronide. This would
indicate that the carbohydrate moiety may not undergo hydrolysis in
the liver. Understanding the unique mechanism by which the
compounds of the present invention exhibit antitumor activity in
mice and rats will serve to clarify the mechanism of action of
mycophenolic acid.
In another aspect, the compounds of Formula I wherein R' represents
(a) through (g) are useful in the treatment of psoriasis. When used
in carrying out this embodiment, a specified Formula I compound can
be administered to a human suffering from psoriasis orally,
parenterally or topically. When administered topically, an amount
of specified Formula I compound effective for treating psoriasis is
applied directly to the psoriatic lesion. For oral use, a specified
Formula I compound is administered orally in tablets or capsules or
in a liquid solution or suspension. A preferred mode for oral
administration is via gelatin capsules. A typical formulation in
capsules is as follows: 9.4 kg of specified Formula I compound is
thoroughly mixed with 4.7 kg of starch, and the mixture is loaded
into empty telescoping gelatin capsules. Each capsule contains the
following ingredients:
400 mg specified Formula I compound
200 mg starch
For topical use it is preferable to formulate the compounds of the
present invention, for example, as ointments or solutions.
A typical ointment useful in applying a specified Formula I
compound to a psoriatic lesion contains the following ingredients
per gram of ointment:
Specified Formula I compound 50 mg Polyethylene glycol 300 (N.F.)
600 mg Polyethylene glycol 4000 (U.S.). 350 mg
A typical solution contains the following ingredients per gram of
solution:
Specified Formula I compound 50 mg Polyethylene glycol 300 (N.F.)
950 mg
For topical administration, a specified compound of Formula I,
formulated as indicated above, is applied to a psoriatic lesion at
a rate varying from 3 mcg per square cm of skin surface per day up
to 300 mcg per square cm of skin surface per day until the
psoriatic process is checked. The typical formulation can be
applied daily for 14 days using a continuous occlusive dressing.
The concentration of specified Formula I compound in the
formulation can vary from about 0.05 percent to about 5 percent;
with these concentrations a dose of 0.01 ml of, for example,
ointment per square cm of skin surface readily supplies the
necessary amount of specified Formula I compound. The daily topical
dose of specified Formula I compound for a 70-kg person should not
exceed about 1.5 g.
For oral administration, a daily dosage of from about 1 to about 10
g of specified Formula I compound given in divided doses, for
example, 3 to 4 times per day, can be employed, using any of the
commonly accepted oral dosage forms.
In yet another aspect the compounds of Formula I wherein R'
represents (a) through (g) are useful in the treatment of
hyperuricemia. To achieve a uric acid-lowering effect, from about
200 to about 5000 mg/kg/day of a specified Formula I compound is
administered either orally or parenterally to a human with an
elevated serum uric acid level. Although any specified Formula I
compound may be employed for oral administration, the alkali-metal
salts of the Formula I compounds wherein R is OH are customarily
employed for parenteral administration. Of the alkali-metal salts,
the sodium and potassium salts are especially useful.
When preparing specified Formula I compounds for parenteral
administration, it is convenient to formulate the agent into
ampoules. For example, an ampoule can be prepared containing 220 mg
of sodium
6-[4-(.beta.-D-glucopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-me
thyl-4-hexenoate, 5 mg of phenol and 2 ml of water. Similarly,
ampoules containing 620 mg of sodium
6-[4-(.beta.-D-glucopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-me
thyl-4-hexenoate, 0.4 ml of ethanol, 0.042 mg of benzyl alcohol, 10
mg of phenol, 14 mg of monobasic potassium phosphate, 10 mg of
sodium citrate and 4 ml of water can be used. The pH of this
solution is adjusted, if necessary, to about pH 7 by addition of
acid or base, as required prior to placing in ampoules.
For oral administration, it is preferable to administer the
compounds in telescoping gelatin capsules. For example, capsules
can be prepared, each containing 260 mg of
6-[4-(.beta.-D-glucopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-me
thyl-4-hexenoic acid and up to 700 mg of talc, silica gel, starch,
or microcrystalline cellulose singly or in combination, up to 20 mg
of magnesium stearate and up to 50 mg of stearic acid.
The preparation of compounds of the present invention is further
illustrated by the following specific examples:
EXAMPLE 1
Ethyl
6-[4-(2,3,4,6-tetra-O-acetyl-.beta.-D-glucopyranosyl)-6-methoxy-7-methyl-3
-oxo-5-phthalanyl]-4-methyl-4-hexanoate
2,3,4,6-Tetra-O-acetyl-.alpha.,D-glucopyranosyl bromide (10.2 g)
was added to a solution of the ethyl ester of mycophenolic acid
(17.4 g) and N-ethyldiisopropylamine (10 g) in dimethylformamide
(80 ml); the mixture was stirred and heated at
85.degree.-90.degree.C. in an oil bath. After 2 hours, more
2,3,4,6-tetra-O-acetyl-.alpha.,D-glucopyranosyl bromide (10.2 g)
was added; this mixture was stirred and heated for five hours. At
this time a third portion of
2,3,4,6-tetra-O-acetyl-.alpha.,D-glucopyranosyl bromide (10 g) and
more N-ethyldiisopropylamine (5 g) were added; this mixture was
stirred and heated for 18 hours. At this point a fourth portion of
2,3,4,6-tetra-O-acetyl-.alpha.,D-glucopyranosyl bromide (10 g) was
added; this mixture was stirred and heated for another 4 hours. The
reaction mixture thus obtained was poured into 1 liter of xylene,
and the resulting solution was chilled in a refrigerator for 1
hour. A precipitate formed and was separated by filtration, washing
with xylene. The combined filtrates were evaporated under vacuum,
and the residue thus obtained was taken into diethyl ether (about
800 ml). The undissolved solids were removed by filtration, and the
diethyl ether filtrate was evaporated under vacuum to give ethyl
6-[4-(2,3,4,6-tetra-O-acetyl-.beta.-D-glucopyranosyl)-6-methoxy-7-methyl-3
-oxo-5-phthalanyl]-4-methyl-4-hexenoate: nmr indicated the presence
of four acetyl peaks at .delta. 2.1-2.2 ppm.
EXAMPLE 2
Ethyl
6-[4-(.beta.-D-glucopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-me
thyl-4-hexenoate
Ethyl
6-[4-(2,3,4,6-tetra-O-acetyl-.beta.-D-glucopyranosyl)-6-methoxy-7-methyl-3
-oxo-5-phthalanyl]-4-methyl-4-hexenoate obtained as described in
Example 1 was dissolved in 150 ml of ethanol, and this solution was
added to a chilled (ca. -30.degree.C.) solution of ethanol (250
ml)-ammonia (added to give a total volume of about 500 ml). The
resulting solution was allowed to return to room temperature and
then was stirred for 24 hours. The solvents were evaporated under
vacuum. The residue was dissolved in water (250 ml), and this
solution was extracted twice with chloroform (300-ml portions). The
chloroform extract was dried (Na.sub.2 SO.sub.4) and evaporated in
vacuo. The residue was recrystallized twice from ethanol to give
13.6 g of ethyl
6-[4-(.beta.-D-glucopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-me
thyl-4-hexenoate, m.p. 56.degree.-59.degree.C.
Analysis.
Calculated for C.sub.25 H.sub.34 O.sub.11 (percent): C, 58.81; H,
6.71; O, 34.47. Found (percent): C, 58.77; H, 6.59; O, 34.40.
EXAMPLE 3
Methyl
6-[4-(.beta.-D-glucopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-me
thyl-4-hexenoate
Ethyl
6-[4-(.beta.-D-glucopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-me
thyl-4-hexenoate (8 g) was added to a solution of
N-ethyldiisopropylamine (5 g) in methanol (200 ml). The resulting
solution was heated under reflux under nitrogen for 48 hours. The
solvent was then removed in vacuo. The residue thus obtained was
recrystallized from methanol-benzene to give 4.8 g of methyl
6-[4-(.beta.-D-glucopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-me
thyl-4-hexenoate, m.p. 70.degree.-73.degree.C.
Analysis.
Calculated for C.sub.24 H.sub.32 O.sub.11 (percent): C, 58.05; H,
6.50; O, 35.45. Found (percent): C, 58.05; H, 6.42; O, 35.64.
EXAMPLE 4
6-[4-(.beta.-D-glucopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-met
hyl-4-hexenoic acid N-Ethyldiisopropylamine N-Ethylidisopropylamine
(8 ml) and water (10 ml) were added to a solution of ethyl
6-[4-(.beta.-D-glucopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-me
thyl-4-hexenoate (3 g) in methanol (60 ml). The resulting solution
was heated under reflux for 132 hours. Additional
N-ethyldiisopropylamine (2 ml) was added, and refluxing was
continued for 48 more hours. The solvents were evaporated in vacuo,
and the residue thus obtained was dissolved in water (50 ml). This
aqueous solution was adjusted to about pH 7.6 with dilute sodium
hydroxide and then was extracted three times with chloroform (25-ml
portions). The resulting aqueous solution was adjusted to about pH
4.5 with dilute hydrochloric acid and then was extracted twice with
diethyl ether (25-ml portions) and 12 times with chloroform (25-ml
portions). The 12 chloroform extracts were combined, dried
(Na.sub.2 SO.sub.4) and evaporated in vacuo. The residue thus
obtained was crystallized from ethyl acetate-benzene to give 550 mg
of 6
-[4-(.beta.-D-glucopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-met
hyl-4-hexenoic acid, m.p. 179.degree.-181.degree.C.
Analysis.
Calculated for C.sub.23 H.sub.30 O.sub.11 (percent): C, 57.25; H,
6.26; O, 36.47. Found (percent): C, 57.09; H, 6.44; O, 36.44.
EXAMPLE 5
Ethyl
6-[4-(2,3,4,6-tetra-O-acetyl-.beta.-D-galactopyranosyl)-6-methoxy-7-methyl
-3-oxo-5-phthalanyl]-4-methyl-4-hexenoate
2,3,4,6-Tetra-O-acetyl-.alpha.,D-galactopyranosyl bromide (6.7 g)
was added slowly to a solution of the ethyl ester of mycophenolic
acid (6 g) and N-ethyldiisopropylamine (4 g) in dimethylformamide
(20 ml); the mixture was stirred and heated at
75.degree.-80.degree.C. in an oil bath for 48 hours. The reaction
mixture then was added to 200 ml of xylene, and the resulting
solution was refrigerated for 3 hours. A precipitate formed and was
separated by filtration. The filtrate was evaporated in vacuo to
give ethyl
6-[4-(2,3,4,6-tetra-O-acetyl-.beta.-D-galactopyranosyl)-6-methoxy-7-methyl
-3-oxo-5-phthalanyl]-4-methyl hexenoate.
EXAMPLE 6
Ethyl
6-[4-(.beta.-D-galactopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-
methyl-4-hexenoate
Ethyl
6-[4-(2,3,4,6-tetra-O-acetyl-.beta.-D-galactopyranosyl)-6-methoxy-7-methyl
-3-oxo-5-phthalanyl]-4-methyl hexenoate, obtained as described in
Example 5, was dissolved in a chilled (about -30.degree.C.)
solution of ethanol (200 ml) - ammonia (dissolved to give a total
volume of about 400 ml). The resulting solution was allowed to
return to room temperature and then was stirred for 18 hours. The
solvents were removed under vacuum. Water (100 ml) and chloroform
(100 ml) were added to the residue thus obtained. The chloroform
layer was separated. The aqueous layer was extracted further with
chloroform (three 75-ml portions). The combined chloroform extracts
were dried (Na.sub.2 SO.sub.4) and evaporated in vacuo. Water (250
ml) and diethyl ether (150 ml) were added to this residue. The
aqueous layer was separated, was washed twice more with diethyl
ether (150-ml portions), and was evaporated under vacuum. The
resulting residue was crystallized from ethanol to give 1.6 g of
ethyl
6-[4-(.beta.-D-galactopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-
methyl-4-hexenoate, m.p. 64.degree.-68.degree.C.
Analysis.
Calculated for C.sub.25 H.sub.34 O.sub.11 (percent): C, 58.81; H,
6.71; O, 34.47. Found (percent): C, 58.55; H, 6.91; O, 34.75.
EXAMPLE 7
Methyl
6-[4-(.beta.-D-galactopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-
methyl-4-hexenoate
Ethyl
6-[4-(.beta.-D-galactopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-
methyl-4-hexenoate (610 mg) was added to a solution of methanol (20
ml) and N-ethyldiisopropylamine (1 ml). The resulting solution was
heated under reflux for 48 hours. The solvent was evaporated in
vacuo, and the residue thus obtained was crystallized from ethanol
to give 362 mg of methyl
6-[4-(.beta.-D-galactopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-
methyl-4-hexenoate, m.p. 141.degree.-142.degree.C.
Analysis.
Calculated for C.sub.24 H.sub.32 O.sub.11 (percent): C, 58.05; H,
6.50; O, 34.45. Found (percent): C, 57.77; H, 6.58; O, 35.15.
EXAMPLES 8 to 21
Other representative compounds of the present invention, prepared
using the methods described and exemplified hereinabove,
include:
n-Pentyl
6-[4-(.beta.-D-ribofuranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-met
hyl-4-hexenoate
Sodium
6-[4-(.beta.-D-allopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-met
hyl-4-hexenoate
6-[4-(.beta.-D-Gulopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-meth
yl-4-hexenoic acid
Isopropyl
6-[4-(.beta.-D-xylopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-met
hyl-4-hexenoate
6-[4-(.beta.-D-Glucopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-met
hyl-4-hexenamide
Lithium
6-[4-(.beta.-D-ribopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-met
hyl-4-hexenoate
Calcium
6-[4-(.beta.-D-glucopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-me
thyl- 4-hexenoate
Potassium
6-[4-(.beta.-D-galactopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-
methyl-4-hexenoate
Magnesium
6-[4-(.beta.-D-glucopyranosyl)-6-methoxy-7-methyl-3-oxo-5-phthalanyl]-4-me
thyl-4-hexenoate
n-Pentyl
6-[4-(2,3,5-tri-O-benzoyl-.beta.-D-ribofuranosyl)-6-methoxy-7-methyl-3-oxo
-5-phthalanyl]-4-methyl-4-hexenoate
Ethyl
6-[4-(2,3,4,6-tetra-O-propionyl-.beta.-D-allopyranosyl)-6-methoxy-7-methyl
-3-oxo-5-phthalanyl]-4-methyl-4-hexenoate
Methyl
6-[4-(2,3,4-tri-O-benzoyl-.beta.-D-xylopyranosyl)-6-methoxy-7-methyl-3-oxo
-5-phthalanyl]-4-methyl-4-hexenoate
Isopropyl
6-[4-(2,3,4-tri-O-benzoyl-.beta.-D-ribopyranosyl)-6-methoxy-7-methyl-3-oxo
-5-phthalanyl]-4-methyl-4-hexenoate
Ethyl
6-[4-(2,3,4,6-tetra-O-acetyl-.beta.-D-gulopyranosyl)-6-methoxy-7-methyl-3-
oxo-5-phthalanyl]-4-methyl-4-hexenoate.
* * * * *