US3883518A
Expired / Lapsed
US
⏱️ 0.0 years remaining
3-Methylene cephalosporins
Assignee: Merck and Co Inc
•
Filing: 1972-05-15
•
Granted: 1975-05-13
•
Expires: 1992-05-15
Abstract
Abstract 3-Methylene cephalosporins and their salts and esters which are useful as intermediates in the preparation of antibiotics. The title compounds are prepared by the reduction of a 3carbamoyloxymethyl- or 3-acetoxymethyl cephalosporin.
Inventors
- 👤 Gerald S Ponticello
- 👤 F Edward Roberts
- 👤 Leonard M Weinstock
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 17:40
CPC Classifications
C; C07; C07D; C07D501/00; C07D501/02; C07D501/04; C07D501/14
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
5 words
A COMPOUND OF THE FORMULA:
Claim 2
Dependent Claim
5 words
A COMPOUND OF THE FORMULA:
Claim 3
Dependent Claim
13 words
A compound according to claim 1 named methoxymethyl 3-methylene-7 Beta -thienylacetamido-7 Alpha -methoxycepham-4-carboxylate.
Claim 4
Dependent Claim
13 words
A compound according to claim 1 named methoxymethyl 3-methylene-7 Beta -furylacetamido-7 Alpha -methoxycepham-4-carboxylate.
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) | 1978-05-12 | 1978-11-11 | 1979-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-12 | 1982-11-11 | 1983-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-12 | 1986-11-11 | 1987-05-13 | $7700.00 | Window Closed / Lapsed |