Patent US3835138A successfully refreshed from Google Patents.
US3835138A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Bronchodilator 5,6-dihydro-tetrazolo(1,5-c) quinazolines
Assignee: Dow Chemical Co
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Filing: 1972-10-13
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Granted: 1974-09-10
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Expires: 1992-10-13
Abstract
Abstract Tetrazoloquinazoline compounds such as 5,6-dihydro-5-ethyl-8,9dimethoxy-5-methyl-tetrazolo(1,5-c)-quinazoline are prepared by the reaction of a 5-(2-aminophenyl)tetrazole with a ketone or aldehyde. The compounds are useful as bronchodilator agents.
Inventors
- 👤 E Wagner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 15:21
CPC Classifications
C; C07; C07D; C07D487/00; C07D487/02; C07D487/04; C07D487/10; C07D491/00; C07D491/12; C07D491/14
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
12 words
A compound of claim 1 wherein R1 and R2 both represent methoxy.
Claim 2
Dependent Claim
9 words
A compound of claim 2 wherein R3 represents hydrogen.
Claim 3
Dependent Claim
9 words
A compound of claim 2 wherein R4 represents methyl.
Claim 4
Dependent Claim
19 words
A compound of claim 1 wherein R1 and R2 both represent methoxy, R3 represents methyl and R4 represents ethyl.
Claim 5
Dependent Claim
14 words
A compound of claim 1 wherein R1, R2, R3 and R4 all represent hydrogen.
References Cited (Backward Citations)
US3389137A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-09-09 | 1978-03-11 | 1978-09-10 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-09-09 | 1982-03-11 | 1982-09-10 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-09-09 | 1986-03-11 | 1986-09-10 | $7700.00 | Window Closed / Lapsed |