Patent US3933781A successfully refreshed from Google Patents.
US3933781A
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Process for the preparation of α-L-aspartyl-L-phenylalanine alkyl esters
Assignee: Monsanto Co
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Filing: 1973-11-05
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Granted: 1976-01-20
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Expires: 1993-11-05
Abstract
Abstract A process for the preparation of alpha -L-aspartyl-L-phenylalanine alkyl esters wherein L-phenylalanine is reacted with N-protected-L-aspartic anhydride, the resulting product is treated to yield alpha -L-aspartyl-L-phenylalanine which is esterified with an alkanol to yield an alpha -L-aspartyl-L-phenylalanine alkyl ester which is recovered.
Inventors
- 👤 Gerald L. Bachman
- 👤 Marvin L. Oftedahl
- 👤 Billy D. Vineyard
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 23:14
CPC Classifications
C; C07; C07K; C07K5/00; C07K5/04; C07K5/06; C07K5/06104; C07K5/06113; C07K5/06121; C07K5/0613; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/55; Y10; Y10S; Y10S530/00; Y10S530/801
Claims Analysis
Total Claims: 18
Claim 1
Independent Claim
69 words
A process comprising reacting an N-protected-L-aspartic anhydride with L-phenylalanine to form N-protected-α-L-aspartyl-L-phenylalanine wherein the N-protecting group is selected from the group consisting of formyl, acetyl, benzoyl, substituted and unsubstituted carbobenzoxy, t-butoxycarbonyl and the hydrohalide salts, removing the protecting group from the N-protected-α-L-aspartyl-L-phenylalanine to form α-L-aspartyl-L-phenylalanine and esterifying the α-L-aspartyl-L-phenylalanine with an alkanol having from 1 to 3 carbon atoms to form the corresponding α-L-aspartyl-L-phenylalanine alkyl ester which is recovered.
Claim 2
Dependent Claim
69 words
A process comprising reacting an N-protected-L-aspartic anhydride with L-phenylalanine to form N-protected-α-L-aspartyl-L-phenylalanine wherein the N-protecting group is selected from the group consisting of formyl, acetyl, benzoyl, substituted and unsubstituted carbobenzoxy, t-butoxycarbonyl and the hydrohalide salts, removing the protecting group from the N-protected-α-L-aspartyl-L-phenylalanine to form α-L-aspartyl-L-phenylalanine and esterifying the α-L-aspartyl-L-phenylalanine with an alkanol having from 1 to 3 carbon atoms to form the corresponding α-L-aspartyl-L-phenylalanine alkyl ester which is recovered.
Claim 3
Dependent Claim
13 words
A process according to claim 1 wherein the N-protected-L-aspartic anhydride is N-formly-L-aspartic anhydride.
Claim 4
Dependent Claim
21 words
A process according to claim 2 wherein the N-formyl-L-aspartic anhydride is reacted with L-phenylalanine in the presence of glacial acetic acid.
Claim 5
Dependent Claim
16 words
A process according to claim 2 wherein the formyl group is removed from N-formyl-α-L-aspartyl-L-phenylalanine by hydrolysis.
Claim 6
Dependent Claim
23 words
A process according to claim 4 wherein the hydrolysis is carried out by treating the N-formyl-α-L-aspartyl-L-phenylalanine with an aqueous solution of hydrogen chloride.
Claim 7
Dependent Claim
17 words
A process according to claim 1 wherein the esterification is conducted in the presence of hydrogen chloride.
Claim 8
Dependent Claim
20 words
A process according to claim 1 wherein the α-L-aspartyl-L-phenylalanine alkyl ester is recovered in the form of an acid salt.
Claim 9
Dependent Claim
13 words
A process according to claim 7 wherein the acid salt is hydrochloride salt.
Claim 10
Dependent Claim
11 words
A process according to claim 1 wherein the alkanol is methanol.
Claim 11
Dependent Claim
17 words
A process according to claim 9 wherein the esterification is conducted in the presence of hydrogen chloride.
Claim 12
Dependent Claim
20 words
A process according to claim 10 wherein the α-L-aspartyl-L-phenylalanine methyl ester is removed in the form of a hydrochloride salt.
Claim 13
Dependent Claim
54 words
A process comprising reacting N-formyl-aspartic anhydride with l-phenylalanine in glacial acetic acid to form N-formyl-α-L-aspartyl-L-phenylalanine, removing the formyl group from N-formyl-α-L-aspartyl-L-phenylalanine by hydrolysis with an aqueous solution of hydrogen chloride and esterifying the resulting α-L-aspartyl-L-phenylalanine with methanol in the presence of hydrogen chloride to form α-L-aspartyl-L-phenylalanine methyl ester and recovering the α-L-asparatyl-L-phenylalanine methyl ester.
Claim 14
Dependent Claim
54 words
A process comprising reacting N-formyl-aspartic anhydride with l-phenylalanine in glacial acetic acid to form N-formyl-α-L-aspartyl-L-phenylalanine, removing the formyl group from N-formyl-α-L-aspartyl-L-phenylalanine by hydrolysis with an aqueous solution of hydrogen chloride and esterifying the resulting α-L-aspartyl-L-phenylalanine with methanol in the presence of hydrogen chloride to form α-L-aspartyl-L-phenylalanine methyl ester and recovering the α-L-asparatyl-L-phenylalanine methyl ester.
Claim 15
Dependent Claim
2 words
N-protected- α-L-aspartyl-L-phenylalanine.
Claim 16
Dependent Claim
2 words
N-protected- α-L-aspartyl-L-phenylalanine.
Claim 17
Dependent Claim
1 words
N-formyl-α-L-aspartyl-L-phenylalanine.
Claim 18
Dependent Claim
1 words
N-formyl-α-L-aspartyl-L-phenylalanine.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-01-19 | 1979-07-21 | 1980-01-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-01-19 | 1983-07-21 | 1984-01-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-01-19 | 1987-07-21 | 1988-01-20 | $7700.00 | Window Closed / Lapsed |