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US3976680A
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Production of an ester of one enantiomer of an α-amino acid in the form of a salt with an optically active acid
Assignee: Glaxo Laboratories Ltd
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Filing: 1973-02-23
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Granted: 1976-08-24
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Expires: 1993-02-23
Abstract
Abstract A process for the production of an ester of one enantiomer of an α-amino acid in the form of a salt with an optically active acid, which comprises reacting an ester of the opposite enantiomer of said α-amino acid (which may be in admixture with an ester of the desired enantiomer) with said optically active acid and an aldehyde or ketone, whereby an ester of the desired enantiomer separates out in the form of the said salt. The free α-amino acid and/or its salts may be obtained by hydrolysis of the ester thus formed. Optically active α-amino acids and their esters are of use in the synthesis of physiologically active compounds e.g. antibiotics of the penicillin and cephalosporin types. The present invention provides a relatively cheap, high yield process for the production of esters of optically active α-amino acids and for the production of optically active α-amino acids thereform. Certain novel compounds are disclosed.
Inventors
- 👤 John Colin Clark
- 👤 Joseph Elks
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 14:58
CPC Classifications
C; C07; C07B; C07B53/00; C07B57/00; C07C; C07C227/00; C07C227/30; C07C227/32; C07C227/34
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
77 words
A process for the production of an ester of one enantiomer of an α-amino acid in the form of a salt with an optically active acid, which comprises reacting an ester of the opposite enantiomer of said α-amino acid, which may be in admixture with an ester of the desired enantiomer, with said optically active acid and an aldehyde or ketone, whereby an ester of the desired enantiomer separates out in the form of the said salt.
Claim 2
Dependent Claim
77 words
A process for the production of an ester of one enantiomer of an α-amino acid in the form of a salt with an optically active acid, which comprises reacting an ester of the opposite enantiomer of said α-amino acid, which may be in admixture with an ester of the desired enantiomer, with said optically active acid and an aldehyde or ketone, whereby an ester of the desired enantiomer separates out in the form of the said salt.
Claim 3
Dependent Claim
64 words
A process as claimed in claim 1 wherein the said ester of one enantiomer of an α-amino acid is represented by the formula: ##STR14## wherein R represents an unsubstituted or substituted alkyl group with 1 - 6 carbon atoms, an unsubstituted or substituted cycloalkyl group with 5 or 6 carbon atoms, an aralkyl group, or an aryl group; and Ar represents an aryl group.
Claim 4
Dependent Claim
30 words
A process as claimed in claim 2 wherein a compound of formula IV is used in which Ar represents a m-hydroxyphenyl, m- methoxyphenyl, p-chlorophenyl or a m- or p-tolyl group.
Claim 5
Dependent Claim
68 words
A process as claimed in claim 2 wherein the aldehyde or ketone is represented by the formula: R.sup.2 --CO--R.sup.3 III wherein R 2 and R 3 , which may be the same or different, each represents a hydrogen atom or an optically substituted aliphatic, araliphatic, aromatic or heterocyclic group; or R 2 and R 3 together with the carbonyl group to which they are bonded represent a cycloalkanone.
Claim 6
Dependent Claim
29 words
A process as claimed in claim 4 in which the compound of formula III used is acetaldehyde, benzaldehyde, anisaldehyde, p-nitrobenzaldehyde, acetophenone, methyl ethyl ketone, methyl isobutyl ketone or acetone.
Claim 7
Dependent Claim
16 words
A process as claimed in claim 5 wherein the said optically active acid is (+)-tartaric acid.
Claim 8
Dependent Claim
18 words
A process as claimed in claim 6 in which the compound of formula IV used is methyl DL-phenylglycinate.
Claim 9
Dependent Claim
36 words
A process as claimed in claim 7 in which the DL-ester is reacted in the presence of (+)-tartaric acid with benzaldehyde or acetone in ethanol as solvent whereby methyl D-phenylglycinate is obtained as the (+)-hemitartaric salt.
Claim 10
Dependent Claim
17 words
A process as claimed in claim 6 in which the compound of formula IV is ethyl DL-phenylglycinate.
Claim 11
Dependent Claim
38 words
A process as claimed in claim 9 in which the DL-ester is reacted in the presence of (+)-tartaric acid with benzaldehyde or acetone in ethanol or methanol as solvent whereby ethyl D-phenylglycinate is obtained as the (+)-hemitartrate salt.
Claim 12
Dependent Claim
18 words
A process as claimed in claim 6 in which the compound of formula IV used is methyl DL-p-hydroxyphenylglycinate.
Claim 13
Dependent Claim
37 words
A process as claimed in claim 11 in which the DL-ester is reacted in the presence of (+)-tartaric acid with benzaldehyde in acetonitrile or in methanol/benzene as solvent whereby methyl D-p-hydroxyphenylglycinate is obtained as the (+)-hemitartrate salt.
Claim 14
Dependent Claim
18 words
A process as claimed in claim 6 in which the compound of formula IV used is ethyl DL-p-hydroxyphenylglycinate.
Claim 15
Dependent Claim
42 words
A process as claimed in claim 13 in which the DL-ester is reacted in the presence of (+)-tartaric acid with benzaldehyde in methanol/methylene chloride as solvent or with acetone in methanol as solvent whereby ethyl D-p-hydroxyphenylglycinate is obtained as the (+)-hemitartrate salt.
Claim 16
Dependent Claim
71 words
A process as claimed in claim 2 wherein the ester of the enantiomer of the α-amino acid, which may be in the form of a salt with the optically active acid, thus obtained is hydrolysed in an aqueous solution of a strong acid, optionally after preliminary conversion of said salt to the free base, whereby the desired enantiomer of the α-amino acid is obtained in the form of a salt thereof.
Claim 17
Dependent Claim
68 words
A process as claimed in claim 2 wherein the ester of the enantiomer of the α-amino acid, which may be in the form of a salt with the optically active acid, thus obtained is hydrolysed in an aqueous solution of a strong base, optionally after conversion of the said salt to the free base, whereby the desired enantiomer of the α-amino acid or a salt thereof is obtained.
Claim 18
Dependent Claim
67 words
A process as claimed in claim 1 wherein the said ester of one enantiomer of an α-amino acid is represented by the formula: ##STR15## wherein R 1 is optionally substituted alkyl, aralkyl, or cycloalkyl group and R represents an unsubstituted or substituted alkyl group with 1-6 carbon atoms, an unsubstituted or substituted cycloalkyl group with 5 or 6 carbon atoms, an aralkyl group or an aryl group.
Claim 19
Dependent Claim
20 words
A process as claimed in claim 1 wherein the said ester is an ester of a naturally occurring α-amino acid.
References Cited (Backward Citations)
US3887606A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-08-24 | 1980-02-23 | 1980-08-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-08-24 | 1984-02-23 | 1984-08-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-08-24 | 1988-02-23 | 1988-08-24 | $7700.00 | Window Closed / Lapsed |