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US4401820A
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Process for racemizing optically active α-amino acids or a salt thereof
Assignee: Tanabe Pharma Corp
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Filing: 1982-01-05
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Granted: 1983-08-30
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Expires: 2002-01-05
Abstract
Abstract DL- alpha -amino acids or a salt thereof can be obtained by racemizing an optically active alpha -amino acid or a salt thereof in the presence of an aliphatic acid and an aldehyde.
Inventors
- 👤 Ichiro Chibata
- 👤 Shigeki Yamada
- 👤 Chikara Hongo
- 👤 Ryuzo Yoshioka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 22:46
CPC Classifications
C; C07; C07C; C07C227/00; C07C227/36; C07B; C07B55/00; C07C227/38; C07C227/44; C07C229/00; C07C229/02; C07C229/04; C07C229/06; C07C229/08
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
148 words
A process for producing a DL-α-amino acid or a salt thereof which comprises racemizing an optically active α-amino acid or a salt thereof at a temperature of 20° to 120° C. in the presence of 2 to 50 g of an aliphatic acid per g of said optically active acid or salt, said aliphatic acid having the formula R.sup.1 --COOH (I) wherein R 1 is hydrogen or alkyl having 1 to 4 carbon atoms, and 0.001 to 0.5 mole of an aldehyde per mole of said optically active acid or salt, said aldehyde having the formula: R.sup.2 --CHO (II) wherein R 2 is hydrogen; alkyl having 1 to 6 carbon atoms; alkenyl having 2 to 4 carbon atoms; phenyl; phenyl having at least one substituent selected from the class consisting of hydroxy, nitro, amino and alkoxy having 1 to 4 carbon atoms; phenylvinyl; oxygen-containing heteromonocyclic group; and hydroxynaphthyl.
Claim 2
Dependent Claim
148 words
A process for producing a DL-α-amino acid or a salt thereof which comprises racemizing an optically active α-amino acid or a salt thereof at a temperature of 20° to 120° C. in the presence of 2 to 50 g of an aliphatic acid per g of said optically active acid or salt, said aliphatic acid having the formula R.sup.1 --COOH (I) wherein R 1 is hydrogen or alkyl having 1 to 4 carbon atoms, and 0.001 to 0.5 mole of an aldehyde per mole of said optically active acid or salt, said aldehyde having the formula: R.sup.2 --CHO (II) wherein R 2 is hydrogen; alkyl having 1 to 6 carbon atoms; alkenyl having 2 to 4 carbon atoms; phenyl; phenyl having at least one substituent selected from the class consisting of hydroxy, nitro, amino and alkoxy having 1 to 4 carbon atoms; phenylvinyl; oxygen-containing heteromonocyclic group; and hydroxynaphthyl.
Claim 3
Dependent Claim
45 words
The process according to claim 1, wherein the optically active α-amino acid is selected from the group consisting of alanine, valine, leucine, isoleucine, serine, threonine, cystine, cysteine, methionine, tryptophan, phenylalanine, tyrosine, 3-(3,4-dihydroxyphenyl)alanine, phenylglycine, p-hydroxyphenylglycine, arginine, lysine, ornithine, histidine, aspartic acid, glutamic acid, proline and hydroxyproline.
Claim 4
Dependent Claim
74 words
The process according to claim 1, wherein the aliphatic acid is a compound of the formula (I) in which R 1 is hydrogen or alkyl of one to 3 carbon atoms, and the aldehyde is a compound of the formula (II) in which R 2 is hydrogen; alkyl of one to 6 carbon atoms; vinyl, phenyl; phenyl having at least one substituent selected from the class consisting of hydroxy, nitro and methoxy; or furyl.
Claim 5
Dependent Claim
39 words
The process according to claim 1, 2 or 3 wherein the aliphatic acid is formic acid, acetic acid or propionic acid, and the aldehyde is formaldehyde, acetoaldehyde, propionaldehyde, n-butyraldehyde, n-heptylaldehyde, acrolein, benzaldehyde, salicylaldehyde, p-hydroxybenzaldehyde, p-anisaldehyde, o-nitrobenzaldehyde, 5-nitrosalicylaldehyde or furfural.
Claim 6
Dependent Claim
25 words
The process according to claim 4, wherein the aliphatic acid is acetic acid or propionic acid, and the aldehyde is propionaldehyde, n-butyradehyde, benzaldehyde or salicylaldehyde.
Claim 7
Dependent Claim
21 words
The process according to claim 1, 2 or 3, wherein the racemization reaction is carried out at 40° to 100° C.
Claim 8
Dependent Claim
21 words
The process according to claim 1, 2 or 3, wherein the racemization reaction is carried out at 60° to 100° C.
Claim 9
Dependent Claim
31 words
The process according to claim 1, 2 or 3, wherein 0.005 to 0.2 mole of the aldehyde per mole of the optically active α-amino acid or a salt thereof is used.
Claim 10
Dependent Claim
31 words
The process according to claim 1, 2 or 3, wherein 0.01 to 0.2 mole of the aldehyde per mole of the optically active α-amino acid or a salt thereof is used.
Claim 11
Dependent Claim
31 words
The process according to claim 1, 2 or 3, wherein the racemization reaction of the optically active α-amino acid salt is carried out in the presence of a free DL-α-amino acid.
Claim 12
Dependent Claim
27 words
The process according to claim 10, wherein 0.001 to 0.8 mole of the free DL-α-amino acid per mole of the optically active α-amino acid salt is used.
References Cited (Backward Citations)
US2071327A
Cited
US3458568A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-08-29 | 1987-02-28 | 1987-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-08-29 | 1991-02-28 | 1991-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-08-29 | 1995-02-28 | 1995-08-30 | $7700.00 | Window Closed / Lapsed |