US4233456A
Expired / Lapsed
US
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Process for the manufacture of optically active, optionally substituted 2-amino-2-phenylacetic acid
Assignee: Honeywell Riedel de Haen AG
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Filing: 1978-08-28
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Granted: 1980-11-11
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Expires: 1998-08-28
Abstract
Abstract Optically active 2-amino-2-phenylacetic acid of the formula ##STR1## in which R 1 , R 2 and R 3 , which are identical or different, denote hydrogen, halogen, hydroxy, alkyl, acyl, or alkoxy, is prepared by asymmetrical transformation of a corresponding DL-aminophenylacetonitrile with L(+)-tartaric acid. To this end the corresponding DL-2-amino-2-phenyl-acetonitrile is reacted with approximately equimolar amounts of L(+)-tartaric acid in the presence of at least one alkanol having from 1 to 5 carbon atoms and/or at least one carbonyl compound at a temperature of from 0° to 50° C. and the mixture is stirred for 2 to 120 hours at the indicated temperature. The crystallized transformation product is separated, hydrolyzed by treatment with an acid and the desired product is isolated.
Inventors
- 👤 Horst Schmand
- 👤 Wolfgang Dannenberg
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 07:25
CPC Classifications
C; C07; C07C; C07C255/00
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
131 words
A process for the manufacture of an optically active optionally substituted 2-amino-2-phenylacetic acid of the formula ##STR5## wherein R 1 , R 2 and R 3 , which are identical or not all the same, are hydrogen, halogen, hydroxy, alkyl, acyl or alkoxy, which consists essentially of reacting a DL-2-amino-2 -phenyl-acetonitrile of the formula ##STR6## with an approximately equimolar amount of L(+)-tartaric acid in the presence of at least one alkanol of from 1 to 5 carbon atoms at a temperature of from 0° to 50° C.; stirring the reaction mixture for 2 to 120 hours at a temperature of from 0° to 50° C., thereby bringing about asymmetrical transformation; separating the crystallized transformation product; hydrolyzing same by a treatment with an acid; and isolating the optically active 2-amino-2-phenylacetic acid form.
Claim 2
Dependent Claim
131 words
A process for the manufacture of an optically active optionally substituted 2-amino-2-phenylacetic acid of the formula ##STR5## wherein R 1 , R 2 and R 3 , which are identical or not all the same, are hydrogen, halogen, hydroxy, alkyl, acyl or alkoxy, which consists essentially of reacting a DL-2-amino-2 -phenyl-acetonitrile of the formula ##STR6## with an approximately equimolar amount of L(+)-tartaric acid in the presence of at least one alkanol of from 1 to 5 carbon atoms at a temperature of from 0° to 50° C.; stirring the reaction mixture for 2 to 120 hours at a temperature of from 0° to 50° C., thereby bringing about asymmetrical transformation; separating the crystallized transformation product; hydrolyzing same by a treatment with an acid; and isolating the optically active 2-amino-2-phenylacetic acid form.
Claim 3
Dependent Claim
14 words
The process as defined in claim 1, wherein D(-)-2-amino-2-phenylacetic acid is prepared from DL-2-amino-2-phenylacetontrile.
Claim 4
Dependent Claim
14 words
The process as defined in claim 1, wherein D(-)-2-amino-2-(4-methoxyphenyl)-acetic acid is prepared from DL-2-amino-2-(4-methoxyphenyl)-acetonitrile.
Claim 5
Dependent Claim
18 words
The process as defined in claim 1, wherein hydrochloric acid of 20% strength is used for the hydrolysis.
Claim 6
Dependent Claim
12 words
The process as defined in claim 1, wherein the alkanol is methanol.
Claim 7
Dependent Claim
27 words
The process as defined in claim 1, wherein an amount of from 0.2 to 1 liter of the alkanol is introduced for each mol of the DL-2-amino-2-phenyl-acetonitrile.
Claim 8
Dependent Claim
21 words
The process as defined in claim 6, wherein an amount of from 0.4 to 0.5 liter of the alkanol is introduced.
Claim 9
Dependent Claim
44 words
The process as defined in claim 1, wherein the DL-2-amino-2-phenyl-acetonitrile is reacted with an equimolar amount of L(+)-tartaric acid in an alkanol, and the hemitartrate salt formed as an intermediate is isolated and transformed in an alkanol of from 1 to 5 carbon atoms.
Claim 10
Dependent Claim
21 words
The process as defined in claim 1, wherein the yield of 2-amino-2-phenylacetic acid is greater than 50% calculated on the DL-2-amino-2-phenyl-acetonitrile.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1983-11-11 | 1984-05-12 | 1984-11-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-11-11 | 1988-05-12 | 1988-11-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-11-11 | 1992-05-12 | 1992-11-11 | $7700.00 | Window Closed / Lapsed |