Patent US4395547A successfully refreshed from Google Patents.
US4395547A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for preparing 1-substituted-6-n-propyl-8-methylimidazo[1,5-d]-as-triazin-4(3H)-ones
Assignee: Wyeth Holdings LLC
•
Filing: 1982-02-10
•
Granted: 1983-07-26
•
Expires: 2002-02-10
Abstract
Abstract This disclosure describes a novel process for the preparation of 1-(lower alkyl)substituted derivatives of 6-n-propyl-8-alkylimidazo[1,5-d]-as-triazin-4(3H)-ones which are useful as anti-asthmatic agents.
Inventors
- 👤 Sivaraman Raghu
- 👤 James S. Farina
- 👤 Steven L. Peake
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 13:05
CPC Classifications
C; C07; C07D; C07D233/00; C07D233/54; C07D233/64; A; A61; A61P; A61P11/00; A61P43/00; C07D487/00; C07D487/02; C07D487/04
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
89 words
The process of preparing compounds of the formula: ##STR3## wherein R is methyl, ethyl or n-propyl, R' is methyl, ethyl or phenyl, R" is alkyl, aromatic or heterocyclic which comprises condensing a ketone of the formula: ##STR4## wherein R, R' and R" are as hereinabove defined with a lower alkyl carbazate ester in an inert solvent at 80°-135° for several hours whereby a lower alkyl 3-[1-(2-n-propyl-4-methyl-5-imidazolyl)alkylidene]carbazate of the formula: ##STR5## is obtained; and cyclizing the so obtained imidazolylalkylidene carbazate ester in diphenyl ether at 150°-250° C. for 15-45 minutes.
Claim 2
Dependent Claim
89 words
The process of preparing compounds of the formula: ##STR3## wherein R is methyl, ethyl or n-propyl, R' is methyl, ethyl or phenyl, R" is alkyl, aromatic or heterocyclic which comprises condensing a ketone of the formula: ##STR4## wherein R, R' and R" are as hereinabove defined with a lower alkyl carbazate ester in an inert solvent at 80°-135° for several hours whereby a lower alkyl 3-[1-(2-n-propyl-4-methyl-5-imidazolyl)alkylidene]carbazate of the formula: ##STR5## is obtained; and cyclizing the so obtained imidazolylalkylidene carbazate ester in diphenyl ether at 150°-250° C. for 15-45 minutes.
References Cited (Backward Citations)
US3840537A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1986-07-25 | 1987-01-24 | 1987-07-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-07-25 | 1991-01-24 | 1991-07-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-07-25 | 1995-01-24 | 1995-07-26 | $7700.00 | Window Closed / Lapsed |