Patent US4022963A successfully refreshed from Google Patents.
US4022963A
Expired / Lapsed
US
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Acetylation process for nucleoside compounds
Assignee: Individual
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Filing: 1975-02-24
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Granted: 1977-05-10
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Expires: 1995-02-24
Abstract
Abstract A method of acetylation of all the hydroxyl groups in the sugar portion of nucleosides which comprises adding acetic acid to a nucleoside to be acetylated in a vessel provided with a reflux condenser, and heating the mixture in the absence of a catalyst until refluxing begins, adding an excess over the stoichiometric amount of acetic anhydride. Continued heating of the mixture is maintained until the reaction is complete and is followed by stripping off acetic acid and any excess acetic anhydride, and the recovery of the acetylated nucleoside product.
Inventors
- 👤 Daniel H. Deutsch
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 06:52
CPC Classifications
C; C07; C07H; C07H19/00; C07H19/02; C07H19/04; C07H19/06
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
101 words
A method of acetylation of all hydroxyl groups in the sugar portion of nucleosides comprising: adding acetic acid to a nucleoside to be acetylated selected from the group consisting essentially of 6-azauridine, thymidine, uridine, and uracil beta-D-arabinofuranoside; heating the mixture in the absence of pyridine and further in the absence of any catalyst until reflux begins; adding an excess of acetic anhydride to the mixture; continue heating the resulting mixture until acetylation of the hydroxyl groups on the sugar moiety is essentially complete; and stripping acetic acid and any excess acetic anhydride off the mixture, and recovering the acetylated nucleoside product.
Claim 2
Independent Claim
101 words
A method of acetylation of all hydroxyl groups in the sugar portion of nucleosides comprising: adding acetic acid to a nucleoside to be acetylated selected from the group consisting essentially of 6-azauridine, thymidine, uridine, and uracil beta-D-arabinofuranoside; heating the mixture in the absence of pyridine and further in the absence of any catalyst until reflux begins; adding an excess of acetic anhydride to the mixture; continue heating the resulting mixture until acetylation of the hydroxyl groups on the sugar moiety is essentially complete; and stripping acetic acid and any excess acetic anhydride off the mixture, and recovering the acetylated nucleoside product.
Claim 3
Dependent Claim
21 words
The method of claim 1 where said acetic anhydride is added at a rate sufficient to cause the mixture to reflux.
Claim 4
Dependent Claim
18 words
The method of claim 1 wherein said heating step is continued after the addition of said acetic anhydride.
Claim 5
Dependent Claim
27 words
The method of claim 1 wherein the amount of said acetic acid added is between 1 and 15 parts of acetic acid for each part of nucleoside.
Claim 6
Dependent Claim
23 words
The method of claim 1 wherein the excess of said acetic anhydride is between 2 and 30 weight percent above that stoichiometrically required.
Claim 7
Dependent Claim
10 words
The method of claim 1 wherein said nucleoside is 6-azauridine.
Claim 8
Dependent Claim
10 words
The method of claim 1 wherein said nucleoside is thymidine.
Claim 9
Dependent Claim
10 words
The method of claim 1 wherein said nucleoside is uridine.
Claim 10
Dependent Claim
11 words
The method of claim 1 wherein said nucleoside is uracil beta-D-arabinofuranoside.
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) | 1980-05-09 | 1980-11-08 | 1981-05-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-05-09 | 1984-11-08 | 1985-05-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-05-09 | 1988-11-08 | 1989-05-10 | $7700.00 | Window Closed / Lapsed |