U.S. patent application number 15/430786 was filed with the patent office on 2017-07-20 for processes for preparing (r)-1-(5-chloro-[1,1`-biphenyl]-2-yl)-2,2,2-trifluoroethanol and 1-(5-chloro-[1,1`-biphenyl]-2-yl)-2,2,2-trifluoroethanone.
The applicant listed for this patent is Karos Pharmaceuticals, Inc.. Invention is credited to Stephane De Lombaert, Daniel R. Goldberg.
Application Number | 20170204041 15/430786 |
Document ID | / |
Family ID | 56849552 |
Filed Date | 2017-07-20 |
United States Patent
Application |
20170204041 |
Kind Code |
A1 |
De Lombaert; Stephane ; et
al. |
July 20, 2017 |
PROCESSES FOR PREPARING
(R)-1-(5-CHLORO-[1,1`-BIPHENYL]-2-YL)-2,2,2-TRIFLUOROETHANOL AND
1-(5-CHLORO-[1,1`-BIPHENYL]-2-YL)-2,2,2-TRIFLUOROETHANONE
Abstract
The present invention relates to processes for the preparation
of (R)-1-(5-chloro-[1,1'-biphenyl]-2-yl)-2,2,2-trifluoroethanol,
1-(5-chloro-[1,1'-biphenyl]-2-yl)-2,2,2-trifluoroethanone, and
intermediates thereof, which are useful in the preparation of
inhibitors of TPH1 for the treatment of, for example,
gastrointestinal, cardiovascular, pulmonary, inflammatory,
metabolic, low bone mass diseases, serotonin syndrome, and
cancer.
Inventors: |
De Lombaert; Stephane;
(Brisbane, CA) ; Goldberg; Daniel R.; (Seattle,
WA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Karos Pharmaceuticals, Inc. |
New Haven |
CT |
US |
|
|
Family ID: |
56849552 |
Appl. No.: |
15/430786 |
Filed: |
February 13, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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15059627 |
Mar 3, 2016 |
9611201 |
|
|
15430786 |
|
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62128652 |
Mar 5, 2015 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C07C 259/10 20130101;
C07C 29/32 20130101; C07C 49/80 20130101; C07C 29/143 20130101;
C07B 2200/07 20130101; C07C 45/455 20130101; C07C 29/32 20130101;
C07C 33/46 20130101; C07C 29/143 20130101; C07C 33/46 20130101;
C07C 45/455 20130101; C07C 49/80 20130101 |
International
Class: |
C07C 49/80 20060101
C07C049/80 |
Claims
1-81. (canceled)
82. A compound which is a compound of Formula B: ##STR00026##
83. A compound which is a compound of Formula 1-3: ##STR00027##
wherein X is I.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to processes for the
preparation of
(R)-1-(5-chloro-[1,1'-biphenyl]-2-yl)-2,2,2-trifluoroethanol,
1-(5-chloro-[1,1'-biphenyl]-2-yl)-2,2,2-trifluoroethanone, and
intermediates thereof, which are useful in the synthesis of
inhibitors of TPH1 for the treatment of, for example,
gastrointestinal, cardiovascular, pulmonary, inflammatory,
metabolic, low bone mass diseases, serotonin syndrome, and
cancer.
BACKGROUND OF THE INVENTION
[0002] Two vertebrate isoforms of TPH, namely TPH1 and TPH2, have
been identified. TPH1 is primarily expressed in the pineal gland
and non-neuronal tissues, such as enterochromaffin (EC) cells
located in the gastrointestinal (GI) tract. TPH2 (the dominant form
in the brain) is expressed exclusively in neuronal cells, such as
dorsal raphe or myenteric plexus cells. TPH catalyzes the
hydroxylation of tryptophan in the biosynthesis of 5-HT. Thus, the
pharmacological effects of 5-HT can be modulated by agents
affecting TPH.
[0003] TPH1 inhibitors are known in the art. Spirocyclic compounds
disclosed in U.S. Ser. No. 14/477,948, filed Sep. 5, 2014, can
inhibit TPH1 and were found to reduce peripheral serotonin levels
in animal models. The preparation of these compounds can include
the coupling of an alcohol with a chloro-substituted heteroaromatic
compound in the presence of base to yield an ether intermediate
that can be used to make the final TPH1 inhibitor product. A
particular chiral alcohol useful in the synthesis of TPH1
inhibitors is
(R)-1-(5-chloro-[1,1'-biphenyl]-2-yl)-2,2,2-trifluoroethanol (see
Formula A below). According to U.S. Ser. No. 14/477,948, this
chiral alcohol is made by the coupling of phenyl boronic acid with
(R)-1-(2-bromo-4-chlorophenyl)-2,2,2-trifluoroethanol. Alternative
processes for the preparation of the compound of Formula A are
provided herein.
SUMMARY OF THE INVENTION
[0004] The present invention provides processes for preparing
(R)-1-(5-chloro-[1,1'-biphenyl]-2-yl)-2,2,2-trifluoroethanol
(Formula A) and
1-(5-chloro-[1,1'-biphenyl]-2-yl)-2,2,2-trifluoroethanone (Formula
B):
##STR00001##
as described herein.
DETAILED DESCRIPTION
[0005] The present invention provides processes for preparing
(R)-1-(5-chloro-[1,1'-biphenyl]-2-yl)-2,2,2-trifluoroethanol
(Formula A) and
1-(5-chloro-[1,1'-biphenyl]-2-yl)-2,2,2-trifluoroethanone (Formula
B) as set out, for example, in Scheme I, wherein X is selected from
Br and I.
##STR00002##
[0006] In some embodiments, the invention relates to a process for
preparing a compound of Formula A:
##STR00003##
comprising, reacting a compound of Formula 1-4:
##STR00004##
wherein X is selected from Br and I, with phenylboronic acid to
produce the compound of Formula A.
[0007] In some aspects of these embodiments, X is I. In other
aspects of these embodiments, X is Br.
[0008] In some aspects of these embodiments, the reacting can be
carried out under Suzuki coupling conditions such as in the
presence of a Pd catalyst, for example, Pd.sub.2(dppf)Cl.sub.2. In
further aspects of these embodiments, the reacting can be carried
out in the presence of a solvent comprising, for example, dioxane
and/or aqueous sodium carbonate. In further aspects of these
embodiments, to facilitate the reacting, the coupling can be
carried out at elevated temperature such as from 80 to 100.degree.
C. or at about 90.degree. C.
[0009] In some embodiments, the compound of Formula 1-4:
##STR00005##
[0010] wherein X is selected from Br and I,
[0011] is prepared by reducing a compound of Formula 1-3:
##STR00006##
[0012] in the presence of a chiral catalyst.
[0013] In some aspects of these embodiments, X is I. In other
aspects of these embodiments, X is Br.
[0014] In some aspects of these embodiments, the chiral catalyst
comprises iridium such as the Ir catalyst that can be prepared by
combining dichloro(pentamethylcyclopentadienyl)iridium(III) dimer
with (1R,
2R)-(-)-N-(4-toluenesulfonyl)-1,2-diphenylethylenediamine. In some
aspects of these embodiments, the reduction is carried out at
elevated temperature such as at about 30-50.degree. C. or at about
40.degree. C. In further aspects of these embodiments, the
reduction is carried out in the presence of formate as a reductant.
The formate can be in the form of salt such as a potassium salt or
sodium salt. In further aspects of these embodiments, the reduction
is carried out in the presence of a solvent which, for example, can
comprise acetonitrile.
[0015] In some embodiments, the compound of Formula 1-3:
##STR00007##
[0016] wherein X is selected from Br and I,
[0017] is prepared by combining a compound of Formula 1-2:
##STR00008##
[0018] with trifluoromethyltrimethylsilane (TMSCF.sub.3).
[0019] In some aspects of these embodiments, X is I. In other
aspects of these embodiments, X is Br.
[0020] In some aspects of these embodiments, the combining is
carried out in the presence of CsF. In further aspects of these
embodiments, the combining is carried out at a reduced temperature
such as at about -10 to 10.degree. C., or at about 0.degree. C. In
further aspects of these embodiments, the combining is carried out
in the presence of a solvent optionally comprising, for example, an
aromatic solvent like toluene. In further aspects of these
embodiments, the combining further comprises the step of adding
tetra-n-butylammonium fluoride (TBAF), for example, after the
compound of Formula 1-2 is combined with TMSCF.sub.3.
[0021] In some embodiments, the compound of Formula 1-2:
##STR00009##
[0022] wherein X is selected from Br and I,
[0023] is prepared by coupling a compound of Formula 1-1:
##STR00010##
[0024] with N,O-dimethylhydroxylamine hydrochloride.
[0025] In some aspects of these embodiments, X is I. In other
aspects of these embodiments, X is Br.
[0026] In some aspects of these embodiments, the coupling is
carried out in the presence of a tertiary amine such as
triethylamine (TEA). In further aspects of these embodiments, the
coupling is carried out in the presence of a peptide coupling
reagent such as
(1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium
3-oxid hexafluorophosphate) (HATU). In further aspects of these
embodiments, the coupling is carried out using oxalyl chloride. In
further aspects of these embodiments, the coupling is carried out
in the presence of a solvent optionally comprising, for example,
dimethylformamide (DMF), or, for example, dichloromethane
(CH.sub.2Cl.sub.2).
[0027] In some embodiments, the invention relates to a process for
preparing a compound of Formula B:
##STR00011##
wherein X is selected from Br and I, comprising reacting a compound
of Formula 1-3:
##STR00012##
with phenylboronic acid to produce the compound of Formula B;
[0028] In some aspects of these embodiments, X is I. In other
aspects of these embodiments, X is Br.
[0029] In some aspects of these embodiments, the reacting can be
carried out under Suzuki coupling conditions such as in the
presence of a Pd catalyst, for example, Pd.sub.2(dppf)Cl.sub.2. In
further aspects of these embodiments, the reacting can be carried
out in the presence of a solvent comprising, for example, dioxane
and/or aqueous sodium carbonate. In further aspects of these
embodiments, to facilitate the reacting, the coupling can be
carried out at elevated temperature such as from 80 to 100.degree.
C. or at about 90.degree. C.
[0030] In some embodiments, the invention relates to a process for
preparing a compound of Formula A:
##STR00013##
[0031] comprising reducing a compound of Formula B:
##STR00014##
[0032] in the presence of a chiral catalyst.
[0033] In some aspects of these embodiments, the chiral catalyst
comprises iridium such as the Ir catalyst that can be prepared by
combining dichloro(pentamethylcyclopentadienyl)iridium(III) dimer
with (1R,
2R)-(-)-N-(4-toluenesulfonyl)-1,2-diphenylethylenediamine. In
further aspects of these embodiments, the reduction is carried out
at elevated temperature such as at about 30-50.degree. C. or at
about 40.degree. C. In further aspects of these embodiments, the
reduction is carried out in the presence of formate as a reductant.
The formate can be in the form of salt such as a potassium salt or
sodium salt. In further aspects of these embodiments, the reduction
is carried out in the presence of a solvent which, for example, can
comprise acetonitrile.
[0034] In some embodiments, the present invention is directed to a
compound of Formula A prepared by a process described herein.
[0035] In some embodiments, the invention is directed to a compound
of Formula B:
##STR00015##
[0036] In some embodiments, the invention is directed to a compound
of Formula B prepared by a process described herein.
[0037] In some embodiments, the invention is directed toward a
compound of Formula 1-4:
##STR00016##
[0038] wherein X is selected from Br and I.
[0039] In some aspects of these embodiments, X is I. In other
aspects of these embodiments, X is Br.
[0040] In some embodiments, the invention is directed to a compound
of Formula 1-4 prepared by a process described herein.
[0041] In some embodiments, the invention is directed toward a
compound of Formula 1-3:
##STR00017##
[0042] wherein X is selected from Br and I.
[0043] In some aspects of these embodiments, X is I. In other
aspects of these embodiments, X is Br.
[0044] In some embodiments, the invention is directed to a compound
of Formula 1-3 prepared by a process described herein.
[0045] In some embodiments, the invention is directed toward a
compound of Formula 1-2:
##STR00018##
[0046] wherein X is selected from Br and I.
[0047] In some aspects of these embodiments, X is I. In other
aspects of these embodiments, X is Br.
[0048] In some embodiments, the invention is directed to a compound
of Formula 1-2 prepared by a process described herein.
[0049] It is appreciated that certain features of the invention,
which are, for clarity, described in the context of separate
embodiments, can also be provided in combination in a single
embodiment. Conversely, various features of the invention which
are, for brevity, described in the context of a single embodiment,
can also be provided separately or in any suitable subcombination.
While certain of the processes steps are illustrated in Scheme I
above, it is intended that the individual process steps may be
claimed individually or in any combination. It is not intended that
the processes be limited to an overall process having each and
every step depicted in Scheme I.
[0050] The term "compound," as used herein, is meant to include all
stereoisomers, geometric isomers, tautomers, and isotopes of the
structures depicted. Compounds herein identified by name or
structure as one particular tautomeric form are intended to include
other tautomeric forms unless otherwise specified. Compounds herein
identified by name or structure without specifying the particular
configuration of a stereocenter are meant to encompass all the
possible configurations at the stereocenter. For example, if a
particular stereocenter in a compound of the invention could be R
or S, but the name or structure of the compound does not designate
which it is, than the stereocenter can be either R or S.
[0051] The term "compound," as used herein, is further meant to
include all isotopes of atoms occurring in the structures depicted.
Isotopes include those atoms having the same atomic number but
different mass numbers. For example, isotopes of hydrogen include
tritium and deuterium.
[0052] In some embodiments, the compounds disclosed herein are
substantially isolated. By "substantially isolated" is meant that
the compound is at least partially or substantially separated from
the environment in which it was formed or detected. Partial
separation can include, for example, a composition enriched in the
compounds of the invention. Substantial separation can include
compositions containing at least about 50%, at least about 60%, at
least about 70%, at least about 80%, at least about 90%, at least
about 95%, at least about 97%, or at least about 99% by weight of
the compounds of the invention, or salt thereof.
[0053] As used herein, the phrase "elevated temperature" refers to
a temperature higher than about room temperature (20-26.degree.
C.).
[0054] As used herein, the phrase "reduced temperature" refers to a
temperature lower than about room temperature.
[0055] As used herein, the phrase "Suzuki coupling conditions"
refers to reaction conditions that result in the formation of a
carbon-carbon bond between aromatic moieties, one of which includes
a halogen substituent and the other which includes a boronic acid
or boronate substituent, where the reaction is carried out in the
presence of a Pd(0) catalyst.
[0056] As used herein, the phrase "chiral catalyst" is a substance
that pushes a reaction to favor one stereoisomer over another. In
some embodiments, the chiral catalyst is a chiral coordination
complex, such as a chiral coordination complex of iridium.
[0057] The present application also includes salts of the compounds
described herein. In some embodiments, the salts are
pharmaceutically acceptable salts which are conventional non-toxic
salts of the parent compound formed, for example, from non-toxic
inorganic or organic acids. Lists of suitable salts are found in
Remington's Pharmaceutical Sciences, 17.sup.th ed., Mack Publishing
Company, Easton, Pa., 1985, p. 1418 and Journal of Pharmaceutical
Science, 66, 2 (1977), each of which is incorporated herein by
reference in its entirety. The phrase "pharmaceutically acceptable"
is employed herein to refer to those compounds, materials,
compositions, and/or dosage forms which are, within the scope of
sound medical judgment, suitable for use in contact with the
tissues of human beings and animals without excessive toxicity,
irritation, allergic response, or other problem or complication,
commensurate with a reasonable benefit/risk ratio.
[0058] The processes described herein can be monitored according to
any suitable method known in the art. For example, product
formation can be monitored by spectroscopic means, such as nuclear
magnetic resonance spectroscopy (e.g., .sup.1H or .sup.13C),
infrared spectroscopy, spectrophotometry (e.g., UV-visible), or
mass spectrometry; or by chromatography such as high performance
liquid chromatography (HPLC) or thin layer chromatography. The
compounds obtained by the reactions can be purified by any suitable
method known in the art. For example, chromatography (medium
pressure) on a suitable adsorbent (e.g., silica gel, alumina and
the like), HPLC, or preparative thin layer chromatography;
distillation; sublimation, trituration, or recrystallization. The
purity of the compounds, in general, are determined by physical
methods such as measuring the melting point (in case of a solid),
obtaining a NMR spectrum, or performing a HPLC separation. If the
melting point decreases, if unwanted signals in the NMR spectrum
are decreased, or if extraneous peaks in an HPLC trace are removed,
the compound can be said to have been purified. In some
embodiments, the compounds are substantially purified.
[0059] Preparation of compounds can involve the protection and
deprotection of various chemical groups. The need for protection
and deprotection, and the selection of appropriate protecting
groups can be readily determined by one skilled in the art. The
chemistry of protecting groups can be found, for example, in Wuts
and Greene, Greene's Protective Groups in Organic Synthesis,
4.sup.th Ed., John Wiley & Sons: New York, 2006, which is
incorporated herein by reference in its entirety.
[0060] The reactions of the processes described herein can be
carried out in suitable solvents which can be readily selected by
one of skill in the art of organic synthesis. Suitable solvents can
be substantially non-reactive with the starting materials
(reactants), the intermediates, or products at the temperatures at
which the reactions are carried out, i.e., temperatures which can
range from the solvent's freezing temperature to the solvent's
boiling temperature. A given reaction can be carried out in one
solvent or a mixture of more than one solvent. Depending on the
reaction step, suitable solvent(s) for that particular reaction
step can be selected. Example solvents include water, alkanes (such
as pentanes, hexanes, heptanes, cyclohexane, etc., or a mixture
thereof), aromatic solvents (such as benzene, toluene, xylene,
etc.), alcohols (such as methanol, ethanol, isopropanol, etc.),
ethers (such as dialkylethers, methyl tent-butyl ether (MTBE),
tetrahydrofuran (THF), dioxane, etc.), esters (such as ethyl
acetate, butyl acetate, etc.), halogenated hydrocarbon solvents
(such as dichloromethane (DCM), chloroform, dichloroethane,
tetrachloroethane), dimethylformamide (DMF), dimethylsulfoxide
(DMSO), acetone, acetonitrile (ACN), hexamethylphosphoramide (HMPA)
and N-methyl pyrrolidone (NMP). Such solvents can be used in either
their wet or anhydrous forms.
EXAMPLES
[0061] The invention will be described in greater detail by way of
specific examples. The following examples are offered for
illustrative purposes, and are not intended to limit the invention
in any manner. Those of skill in the art will readily recognize a
variety of non-critical parameters which can be changed or modified
to yield essentially the same results.
[0062] .sup.1H NMR Spectra were acquired on a Varian Mercury Plus
400 MHz spectrometer. For typical .sup.1H NMR spectra, the pulse
angle was 45 degrees, 8 scans were summed and the spectral width
was 16 ppm (-2 ppm to 14 ppm). Typically, a total of about 32768
complex points were collected during the 5.1 second acquisition
time, and the recycle delay was set to 1 second. Spectra were
collected at 25.degree. C. .sup.1H NMR Spectra were typically
processed with 0.3 Hz line broadening and zero-filling to about
131072 points prior to Fourier transformation. Chemical shifts were
expressed in ppm relative to tetramethylsilane. The following
abbreviations are used herein: br=broad signal, s=singlet,
d=doublet, dd=double doublet, ddd=double double doublet, dt=double
triplet, t=triplet, td=triple doublet, tt=triple triplet q=quartet,
m=multiplet.
[0063] Liquid chromatography--mass spectrometry (LCMS) experiments
to determine retention times and associated mass ions were
performed using an Agilent Zorbax Bonus RP (reverse phase) column,
2.1.times.50 mm, 3.5 .mu.m particle size, at a temperature of
50.degree. C. and at a flow rate of 0.8 mL/min, 2 .mu.L injection,
mobile phase: (A) water with 0.1% formic acid and 1% acetonitrile,
mobile phase (B) MeOH with 0.1% formic acid; retention time given
in minutes. Method details: (I) ran on a Binary Pump G1312Bwith
UV/Vis diode array detector G1315C and Agilent 6130 mass
spectrometer in positive and negative ion electrospray mode with
UV-detection at 220 and 254 nm with a gradient of 50-95% (B) in a
2.5 min linear gradient (II) hold for 0.5 min at 95% (B) (III)
decrease from 95-5% (B) in a 0.1 min linear gradient (IV) hold for
0.29 min at 5% (B).
Example 1
Preparation of
(R)-1-(5-chloro-[1,1'-biphenyl]-2-yl)-2,2,2-trifluoroethanol
(Formula A)
##STR00019##
[0065] The compound of Formula A was prepared as described below
(see also Scheme I above) using synthetic intermediates 1-1, 1-2,
1-3, and 1-4.
Step 1: 4-chloro-2-iodo-N-methoxy-N-methylbenzamide (1-2, X=I)
##STR00020##
[0066] To a solution of 4-chloro-2-iodobenzoic acid (1-1, X=I)
(CAS#:13421-13-1; Aldrich, SKU: 560146) (3 g, 10.62 mmol) and
N,O-dimethylhydroxylamine hydrochloride (CAS#: 6638-79-5; Sigma
Aldrich, SKU: D163708) (1.2 g, 12.31 mmol) in dimethylformamide
(DMF) (30 mL), was added dropwise triethyl amine (TEA) (7.4 mL,
53.14 mmol), followed by the addition of
(1-[bis(dimethylamino)methylene]-1H-1,2,3-triazolo[4,5-b]pyridinium
3-oxid hexafluorophosphate) (HATU) (6.1 g, 16.05 mmol). The
reaction mixture was stirred at RT for 16 h and then diluted with
CH.sub.2Cl.sub.2 and H20, and the aqueous layer was extracted with
CH.sub.2Cl.sub.2 (4.times.20 mL). The combined organic layers were
washed with brine, dried over Na.sub.2SO.sub.4, filtered,
concentrated in vacuo and purified by silica gel chromatography
(ethyl acetate/hexanes 1:4) to afford the title compound as a white
solid (3.2 g. LCMS (MH+): 325.9. .sup.1H NMR (400 MHz,
CDCl.sub.3-d): .delta.3.11-3.38 (m, 3H), 3.47-3.90 (m, 3H), 7.20
(d, J=8 Hz,1H), 7.37 (d, J=2 Hz, 1H), 7.84 (s,1H).
Step 2: 1-(4-chloro-2-iodophenyl)-2,2,2-trifluoroethanone (1-3,
X=I)
##STR00021##
[0067] To a solution of 4-chloro-2-iodo-N-methoxy-N-methylbenzamide
(1-2, X =I) (Prepared in Step 1: 1.9 g, 5.84 mmol) and CsF (222 mg,
1.46 mmol) in toluene (5 mL), was added dropwise
trifluoromethyltrimethylsilane (TMSCF3) (2.2 mL, 14.88 mmol) at
0.degree. C. The reaction mixture was then warmed to RT and stirred
at that temperature for 20 h. Then, water (6 mL) and
tetra-n-butylammonium fluoride (TBAF) (6 mL, 1 M in THF) were added
to the reaction mixture, and the reaction mixture was heated to
50.degree. C. for 2 h. The reaction mixture was then cooled to RT
and extracted with ethyl acetate (3.times.20 mL). The combined
organic layers were washed with brine, dried over Na.sub.2SO.sub.4,
filtered, concentrated in vacuo and purified by silica gel
chromatography (100% hexanes) to provide the title compound as a
yellow oil (1.39 g). LCMS (MH+): 334.9. .sup.1H NMR (400 MHz,
CDCl.sub.3-d): .delta.7.51 (dd, J=10, 6 Hz,1H), 7.37 (dd, J=10, 7
Hz, 1H), 7.84 (d, J=2 Hz,1H).
Step 3: (R)-1-(4-chloro-2-iodophenyl)-2,2,2-trifluoroethanol
(1-4)
##STR00022##
[0068] To a solution of
1-(4-chloro-2-iodophenyl)-2,2,2-trifluoroethanone (1-3, X=I)
(Prepared in Step 2; 4.0 g, 11.9 mmol) in CH.sub.3CN (20 mL) was
added chiral iridium catalyst (20 mL of a 0.1 mM aqueous solution,
prepared by mixing
dichloro(pentamethylcyclopentadienyl)iridium(III) dimer (CAS#:
12354-84-6, 4.0 mg, 0.005 mmol) and (1R,
2R)-(-)-N-(4-toluenesulfonyl)-1,2-diphenylethylenediamine (CAS#
144222-34-4, Strem Chemicals catalogue #07-2371, 3.6 mg, 0.009
mmol) in water (40 mL) and heating the resultant mixture to
40.degree. C. for 3 h). The reaction mixture was then charged with
potassium formate (HCOOK) (5.03 g, 59.80 mmol), and heated at
40.degree. C. for 12 h. Then the reaction mixture was cooled to RT
and diluted with ethyl acetate and saturated aqueous solution of
NaCl. Layers were separated and the aqueous layer was extracted
with ethyl acetate (4.times.30 mL). The combined organic layers
were washed with brine, dried over Na.sub.2SO.sub.4, filtered, and
concentrated in vacuo to afford the title compound as a yellow
solid (4.1 g, crude) that was used in the following steps without
further purification. LCMS (MH+): 336.9. .sup.1H NMR (400 MHz,
CDCl.sub.3-d): .delta.3.5 (bs, 1H), 5.10 (dd, J=10 Hz, 6 Hz, 1H),
7.29 (dd, J=10, 6 Hz,1H), 7.45 (dd, J=10, 7 Hz,1H),7.71 (d, J=2
Hz,1H).
[0069] Confirmation of the (R) configuration was confirmed by
Mosher Ester analysis. To a solution of
(R)-1-(4-chloro-2-iodophenyl)-2,2,2-trifluoroethanol (50 mg, 0.15
mmol) in tetrahydrofuran (THF) (1 mL, anhydrous) was added
4-dimethylaminopyridine (23 mg, 0.19 mmol) and
(R)-(-)-.alpha.-methoxy-.alpha.-(trifluoromethyl)phenylacetyl
chloride (36 .mu.L, 0.19 mmol). The resulting mixture was stirred
at room temperature for 1 h then filtered. The filtrate was
concentrated and purified by preparative thin layer chromatography
(TLC) (ethyl actate:hexanes/1:40) to afford
(R)-(R)-1-(4-chloro-2-iodophenyl)-2,2,2-trifluoroethyl
3,3,3-trifluoro-2-methoxy-2-phenylpropanoate (50 mg, 0.09 mmol, 98%
e.e. which was confirmed by .sup.1H NMR).
Step 4:
(R)-1-(5-chloro-[1,1'-biphenyl]-2-yl)-2,2,2-trifluoroethanol
(Formula A)
[0070] A solution of
(R)-1-(4-chloro-2-iodophenyl)-2,2,2-trifluoroethanol (1-4) (3.1 g,
9.21 mmol), phenylboronic acid (CAS#: 98-80-6; Sigma Aldrich, SKU
P20009) (1.2 g, 10.2 mmol), and Pd(dppf)Cl.sub.2 (CAS#72287-26-4;
Sigma Aldrich SKU: 697230) (337 mg, 0.46 mmol) in dioxane (30.0 mL)
and Na.sub.2CO.sub.3 (10.0 mL, 2.0 M aqueous solution) was purged
with Na three times, and the resultant reaction mixture was heated
to 90.degree. C. for 2 h. The reaction mixture was then cooled to
RT and diluted with CH.sub.2Cl.sub.2 and water. Layers were
separated and the aqueous layer was extracted with CH.sub.2Cl.sub.2
(3.times.50 mL). The combined organic layers were washed with
brine, dried over Na.sub.2SO.sub.4, filtered, and purified by
silica gel chromatography (ethyl actate/hexanes 1/10) to afford the
title compound as a white solid (2.4 g over 2 steps). .sup.1H NMR
(400 MHz, CDCl.sub.3-d): .delta.3.51 (m, 1H), 5.08-5.13 (q, J=20, 7
Hz,1H),7.26-7.30 (m,4H), 7.42-7.46 (m, 3H), 7.70 (d,J=8 Hz,1H). The
(R) configuration of the title product was confirmed by Mosher
Ester analysis (98% e.e.) as described above for the product of
Step 1: (R)-1-(4-chloro-2-iodophenyl)-2,2,2-trifluoroethanol.
Example 2
Preparation of
1-(5-chloro-[1,1'-biphenyl]-2-yl)-2,2,2-trifluoroethanone (Formula
B)
##STR00023##
[0072] The compound of Formula B was prepared as described below
(see also Scheme I above) using synthetic intermediates 1-1, 1-2,
and 1-3.
Step 1: 4-chloro-2-iodo-N-methoxy-N-methylbenzamide (1-2, X=I)
##STR00024##
[0073] To a solution of 4-chloro-2-iodobenzoic acid (1-1, X=I) (296
g, 1.1 mol) in CH.sub.2Cl.sub.2 (3 L) and DMF (2 mL) was added
oxalyl dichloride (266.1 g, 2.1 mol) dropwise at 0.degree. C. over
a period of 1 h. The resultant reaction mixture was stirred at
0.degree. C. for 2 h and then concentrated in vacuo. The residue
was dissolved in CH.sub.2Cl.sub.2 and concentrated twice. Then the
residue was dissolved in CH.sub.2Cl.sub.2 (1 L) and cooled to
0.degree. C., followed by the dropwise addition of a mixture of
N,O-dimethylhydroxylamine hydrochloride (Sigma Aldrich, SKU:
D163708; 112.4 g, 1.15 mol) in CH.sub.2Cl.sub.2 (1 L) and triethyl
amine (1 L, 3.15 mol) at 0.degree. C. over a period of 1 h. The
reaction mixture was then warmed to RT and stirred at that
temperature for 16 h. After this time, the mixture was diluted with
H.sub.2O and the aqueous layer was extracted with CH.sub.2Cl.sub.2.
The combined organic layers were washed with brine, dried over
Na.sub.2SO.sub.4, filtered, concentrated in vacuo and purified by
silica gel chromatography (ethyl acetate/hexanes 1/4) to afford the
title compound (320 g) as a white solid LCMS (MH+): 325.9. .sup.1H
NMR (400 MHz, CDCl.sub.3-d): .delta.3.11-3.38 (m, 3H), 3.47-3.90
(m, 3H), 7.20 (d, J=8 Hz, 1H), 7.37 (d, J=2 Hz, 1H), 7.84 (s,
1H).
Step 2: 1-(5-chloro-[1,1'-biphenyl]-2-yl)-2,2,2-trifluoroethanone
(Formula B)
[0074] A solution of
1-(4-chloro-2-iodophenyl)-2,2,2-trifluoroethanone (1-3, X=I,
prepared in Example 1, Step 2) (145 g, 0.43 mol), phenylboronic
acid (CAS#: 98-80-6; Sigma Aldrich, SKU P20009; 55.5 g, 0.455 mol)
and Pd(dppf)C12 (CAS#72287-26-4; Sigma Aldrich SKU: 697230; 9.5 g,
0.013 mol) in dioxane (1450 mL) and Na.sub.2CO.sub.3 (435 mL, 2.0 M
aqueous solution) was purged with Na and stirred at 90.degree. C.
for 2 h. After this time, the reaction mixture was cooled to RT and
then diluted with H.sub.2O. Layers were separated and the aqueous
layer was extracted with ethyl acetate and the combined organic
layers were washed with brine, dried over Na.sub.2SO.sub.4,
filtered, concentrated in vacuo and purified by silica gel
chromatography (100% hexanes) to afford the title compound (115 g)
as a white solid. LCMS (MH+): 284.66. .sup.1H NMR (400 MHz,
CDCl.sub.3-d): .delta.7.23-7.27 (m, 2H), 7.42-7.44 (m, 3H),
7.47-7.49 (m, 2H), 7.67-7.70 (m,1H)
Example 3
Preparation of
(R)-1-(5-chloro-[1,1'-biphenyl]-2-yl)-2,2,2-trifluoroethanol
(Formula A)
##STR00025##
[0076] The compound of Formula A was prepared as described below
(see also Scheme I above) using the compound of Formula B as
synthetic starting material.
[0077] To a 22 L 3-necked reactor, fitted with a mechanical
stirrer, a temperature probe, and a N.sub.2 inlet, were charged
sequentially dichloro(pentamethyl cyclopentadienyl)iridium (III)
dimer ([Cp*IrCl2]2, 1.52 g, 1.90 mmol, CAS: 12354-84-6),
(1R,2R)-(-)-(4-toluenesulfonyl)-1,2-diphenylethylenediamine (1.52
g, 4.15 mmol, CAS: 144222-34-4, Strem Chemicals catalogue #07-2371)
and water (8 L) at RT. The resulting reaction mixture was heated to
40.degree. C. for 3 h to provide a homogeneous orange solution. To
this active catalyst solution at the current temperature
(40.degree. C.), was added potassium formate (1476 g, 17.55 mol),
and a solution of
1-(2-phenyl-4-chlorophenyl)-2,2,2-trifluoroethanone (compound of
Formula B prepared in Example 2) (1000 g, 3.51 mol) in CH.sub.3CN
(8 L). The reaction mixture was then stirred at 40.degree. C. for 2
h and then cooled to RT and the layers were separated. The aqueous
layer was extracted with MTBE (2.times.3 L) and the combined
organic layers were dried over Na.sub.2SO.sub.4, filtered, and
concentrated in vacuo to provide
(R)-1-(2-phenyl-4-chlorophenyl)-2,2,2-trifluoroethanol (1006 g) as
a thick yellow oil used without further purification.
[0078] Various modifications of the invention, in addition to those
described herein, will be apparent to those skilled in the art from
the foregoing description. Such modifications are also intended to
fall within the scope of the appended claims. Each reference,
including all patent, patent applications, and publications, cited
in the present application is incorporated herein by reference in
its entirety.
* * * * *