US3725397A
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US
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Method of producing 7{62 -acylamido-3-methylceph-3-em-4-carboxylic acid esters and catalysts therefor
Assignee: Glaxo Laboratories Ltd
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Filing: 1970-03-10
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Granted: 1973-04-03
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Expires: 1990-03-10
Abstract
Abstract The invention relates to a process for the preparation of 7 Beta -acylamido-3-methylceph-3-em-4-carboxylic acid esters from compounds of the penicillin type, in particular, 6 Beta acylamido penicillanic acid 1-oxide esters, in the presence of a catalyst selected from a mono-O-substituted orthophosphoric acid, an 0,0-di(aryl substituted) orthophosphoric acid, a salt or complex formed from a nitrogen base having a pKb of not less than 4 and a mono-0-substituted orthophosphoric acid or an 0,0-di(aryl substituted) orthophosphoric acid. The salt or complex may be formed in situ in the reaction mixture.
Inventors
- 👤 William Graham
- 👤 Lewis Aubrey Wetherill
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 00:52
CPC Classifications
C; C07; C07F; C07F9/00; C07F9/02; C07F9/06; C07F9/08; C07F9/09; C07F9/12
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
14 words
A process as defined in claim 1 wherein said catalyst is said dihydrogen phosphate.
Claim 2
Dependent Claim
33 words
A process as defined in claim 1 wherein said catalyst is a dihydrogen phosphate selected from the group consisting of phenyl dihydrogen phosphate, p-nitrophenyl dihydrogen phosphate, 2-chloromethyl-4-nitrophenyl dihydrogen phosphate and 2,2,2-trichloroethyl dihydrogen phosphate.
Claim 3
Dependent Claim
31 words
A process as defined in claim 1 wherein sAid base is an unsaturated heterocyclic tertiary base selected from the group consisting of pyridine, quinoline, isoquinoline, benzimidazole and lower alkyl derivatives thereof.
Claim 4
Dependent Claim
48 words
A process as defined in claim 1 wherein said nitrogen base is selected from the group consisting of aniline, an N-lower alkyl aniline, a chloroaniline, a lower alkyl aniline, a hydroxy aniline, a lower alkoxy aniline, a nitroaniline and a carboxyaniline, the named substituted anilines being otherwise unsubstituted.
Claim 5
Dependent Claim
56 words
A process as defined in claim 1 wherein said salt is obtained by the reaction of one molar equivalent of the dihydrogen phosphate or hydrogen phosphate with one or two molar equivalents of said nitrogen base or about two molar equivalents of said nitrogen base with one molar equivalent of the dihydrogen phosphate or hydrogen phosphate.
Claim 6
Dependent Claim
25 words
A process as defined in claim 1 in which a proportion of said salt not exceeding 1.0 mole per mole of penicillin oxide is used.
Claim 7
Dependent Claim
24 words
A process as defined in claim 7 wherein the proportion of said salt is from 0.01 to 0.2 mole per mole of penicillin oxide.
Claim 8
Dependent Claim
43 words
A process as defined in claim 1 wherein a solvent selected from the group consisting of dioxan, ethyl methyl ketone, isobutyl methyl ketone, methyl n-propyl ketone, n-propyl acetate, n-butyl acetate, iso-butyl acetate, sec-butyl acetate, diethyl carbonate and diethylene glycol dimethyl ether is employed.
Claim 9
Dependent Claim
46 words
A process as defined in claim 9 in which the reaction is effected at the boiling point of the solvent and wherein a desiccating agent, which is inert under the reaction conditions, is inserted in a reflux return line to remove water formed during the reaction.
References Cited (Backward Citations)
US3275626A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-04-02 | 1976-10-02 | 1977-04-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-04-02 | 1980-10-02 | 1981-04-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-04-02 | 1984-10-02 | 1985-04-03 | $7700.00 | Window Closed / Lapsed |