US4082911A
Expired / Lapsed
US
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Process for the preparation of nucleosides
Assignee: Bayer Pharma AG
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Filing: 1976-02-23
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Granted: 1978-04-04
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Expires: 1996-02-23
Abstract
Abstract The use of trialkylsilyl ester catalysts in place of Lewis acid or Friedel-Crafts catalysts in nucleoside synthesis gives increased yields and a simplified working-up process for recovering the nucleoside product.
Inventors
- 👤 Helmut Vorbruggen
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 21:16
CPC Classifications
C; C07; C07H; C07H19/00; C07H19/02; C07H19/04
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
104 words
In a process for preparing a nucleoside by catalytically condensing a silylated organic base convertible to a nucleoside with a 1-O-acyl, 1-O-alkyl or 1-halo derivative of a masked sugar convertible to a nucleoside to form a nucleoside of said base and said sugar, the improvement which comprises: employing a catalyst for said condensation consisting essentially of a trialkylsilyl ester of an esterifiable mineral acid or of a strong sulfonic acid, each alkyl being of 1-6 carbon atoms and said acid having a --H o constant of at least 12.00, whereby a nucleoside of said base is formed containing principally the β-derivative of said sugar.
Claim 2
Dependent Claim
104 words
In a process for preparing a nucleoside by catalytically condensing a silylated organic base convertible to a nucleoside with a 1-O-acyl, 1-O-alkyl or 1-halo derivative of a masked sugar convertible to a nucleoside to form a nucleoside of said base and said sugar, the improvement which comprises: employing a catalyst for said condensation consisting essentially of a trialkylsilyl ester of an esterifiable mineral acid or of a strong sulfonic acid, each alkyl being of 1-6 carbon atoms and said acid having a --H o constant of at least 12.00, whereby a nucleoside of said base is formed containing principally the β-derivative of said sugar.
Claim 3
Dependent Claim
30 words
A process according to claim 1, further comprising hydrolyzing residual catalyst in the resultant reaction mixture to form a corresponding salt and hexamethyldisiloxane and removing said hexamethyldisiloxane therefrom by evaporation.
Claim 4
Dependent Claim
25 words
A process according to claim 2, wherein hydrolysis is effected by shaking with bicarbonate solution and said evaporation is effected with evaporation of residual solvent.
Claim 5
Dependent Claim
13 words
A process according to claim 1, wherein said catalyst is a trimethylsilyl ester.
Claim 6
Dependent Claim
33 words
A process according to claim 1, wherein said catalyst is (CH 3 ) 3 --SiO--ClO 3 , (CH 3 ) 3 --SiO--SO 2 CF 3 or (CH 3 ) 3 SiOSO 2 F.
Claim 7
Dependent Claim
26 words
A process according to claim 1, wherein the silylated organic base is silylated uracil, cytosine, 6-azauracil, 2-thio-6-azauracil, thymine, N-acetyladenine, guanine, lumazine, imidazole, pyrazine, thiazole or triazole.
Claim 8
Dependent Claim
18 words
A process according to claim 1, wherein the masked sugar is fully masked ribose, deoxyribose, arabinose or glucose.
Claim 9
Dependent Claim
25 words
A process according to claim 6, wherein the masked sugar is fully masked ribose, deoxyribose, arabinose or glucose and said catalyst is a trimethylsilyl ester.
Claim 10
Dependent Claim
33 words
A process according to claim 8, wherein said catalyst is (CH 3 ) 3 --SiO--ClO 3 , (CH 3 ) 3 --SiO--SO 2 CF 3 or (CH 3 ) 3 SiOSO 2 F.
Claim 11
Dependent Claim
30 words
A process according to claim 9, further comprising hydrolyzing residual catalyst in the resultant reaction mixture to form a corresponding salt and hexamethyldisiloxane and removing said hexamethyldisiloxane therefrom by evaporation.
Claim 12
Dependent Claim
25 words
A process according to claim 10, wherein hydrolysis is effected by shaking with bicarbonate solution and said evaporation is effected with evaporation of residual solvent.
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) | 1981-04-03 | 1981-10-03 | 1982-04-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-04-03 | 1985-10-03 | 1986-04-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-04-03 | 1989-10-03 | 1990-04-04 | $7700.00 | Window Closed / Lapsed |