US3856848A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing a protected arginine
Assignee: Eli Lilly and Co
•
Filing: 1973-12-26
•
Granted: 1974-12-24
•
Expires: 1993-12-26
Abstract
Abstract An N , NG, NG-trisubstituted arginine is prepared by treating arginine with a benzyl carbonate or a p-methoxy-benzyl carbonate in the presence of a silylating agent and an amide solvent, and treating the resulting product with a lithium salt of an acid having a pK of from about 4 to about 6 and in the presence of an alcohol.
Inventors
- 👤 E Smithwick
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-29 08:21
CPC Classifications
C; C07; C07C; C07C277/00; C07C277/08
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
10 words
A PROCESS FOR PREPARING A PROTECTED ARGININE OF THE FORMULA
Claim 2
Dependent Claim
10 words
A PROCESS FOR PREPARING A PROTECTED ARGININE OF THE FORMULA
Claim 3
Dependent Claim
27 words
Process of claim 1, in which the arginine is treated with the carbonate and the silylating amide at a temperature of from about 60*C. to about 65*C.
Claim 4
Dependent Claim
13 words
Process of claim 2, in which R2 is pentachlorophenyl and R4 is hydrogen.
Claim 5
Dependent Claim
13 words
Process of claim 3, in which the silylating amide is N-trimethylsilylacetamide or N,O-bis-trimethylsilylacetamide.
Claim 6
Dependent Claim
11 words
Process of claim 4, in which the silylating amide is N-trimethylsilylacetamide.
Claim 7
Dependent Claim
12 words
Process of claim 5, in which the lithium salt is lithium acetate.
Claim 8
Dependent Claim
34 words
Process of claim 6, in which R3OH is methanol or ethanol, and the reaction mixture containing the lithium acetate and the alcohol is treated at a temperature of from about 60*C. to about 80*C.
Claim 9
Dependent Claim
23 words
Process of claim 7, in which Ra is hydrogen, and the product is N ,NG,NG-tribenzyloxycarbonyl-L-arginine produced in the form of its lithium salt.
References Cited (Backward Citations)
US3388113A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-12-23 | 1978-06-24 | 1978-12-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-12-23 | 1982-06-24 | 1982-12-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-12-23 | 1986-06-24 | 1986-12-24 | $7700.00 | Window Closed / Lapsed |