US4247461A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Esterification process using methoxymethyl-P-toluenesulfonate
Assignee: Bristol Myers Co
•
Filing: 1979-11-16
•
Granted: 1981-01-27
•
Expires: 1999-11-16
Abstract
Abstract A new esterifying agent, i.e. methoxymethyl tosylate, is provided for use in preparing methoxymethyl esters of organic carboxylic acids. The new esterifying agent is found to be particularly advantageous in the esterification of penicillin 3-carboxyl groups or cephalosporin 4-carboxyl groups to the methoxymethyl ester group.
Inventors
- 👤 Jeng S. Lin
- 👤 Paul D. Sleezer
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 05:18
CPC Classifications
C; C07; C07D; C07D499/00
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
78 words
In the process for esterifying the 3-carboxyl group of a penicillin or the 4-carboxyl group of a cephalosporin to form a methoxymethyl ester group, the improvement of carrying out the esterification by reaction of the penicillin or cephalosporin free acid or a carboxylic acid salt thereof with methoxymethyl p-toluenesulfonate as the esterifying agent in a substantially anhydrous inert organic solvent in the presence of base and at a temperature of from about -20° C. to about +50° C.
Claim 2
Dependent Claim
78 words
In the process for esterifying the 3-carboxyl group of a penicillin or the 4-carboxyl group of a cephalosporin to form a methoxymethyl ester group, the improvement of carrying out the esterification by reaction of the penicillin or cephalosporin free acid or a carboxylic acid salt thereof with methoxymethyl p-toluenesulfonate as the esterifying agent in a substantially anhydrous inert organic solvent in the presence of base and at a temperature of from about -20° C. to about +50° C.
Claim 3
Dependent Claim
16 words
The process according to claim 1 wherein the [β-lactam] penicillin starting material is hetacillin or heta-amoxicillin.
Claim 4
Dependent Claim
83 words
A process for preparing the methoxymethyl ester of hetacillin which comprises the consecutive steps of (a) dissolving hetacillin in a mixture of a dry inert organic solvent and acetone by addition of triethylamine at a temperature of from -10° to +10° C.; (b) reacting a solution of methoxymethyl p-toluenesulfonate in a dry inert organic solvent with the solution prepared in step (a) at a temperature of from -10° to +10° C.; and (c) recovering the methoxymethyl ester of hetacillin from the reaction mixture.
Claim 5
Dependent Claim
83 words
A process for preparing the methoxymethyl ester of hetacillin which comprises the consecutive steps of (a) dissolving hetacillin in a mixture of a dry inert organic solvent and acetone by addition of triethylamine at a temperature of from -10° to +10° C.; (b) reacting a solution of methoxymethyl p-toluenesulfonate in a dry inert organic solvent with the solution prepared in step (a) at a temperature of from -10° to +10° C.; and (c) recovering the methoxymethyl ester of hetacillin from the reaction mixture.
Claim 6
Dependent Claim
82 words
A process for preparing the methoxymethyl ester of heta-amoxicillin which comprises the consecutive steps of (a) dissolving heta-amoxicillin in a mixture of dry inert organic solvent and acetone by addition of triethylamine at a temperature of from -10° to +10° C.; (b) reacting a solution of methoxymethyl p-toluenesulfonate in a dry inert organic solvent with the solution prepared in step (a) at a temperature of from -10° to +10° C.; and (c) recovering the methoxymethyl ester of heta-amoxicillin from the reaction mixture.
Claim 7
Dependent Claim
82 words
A process for preparing the methoxymethyl ester of heta-amoxicillin which comprises the consecutive steps of (a) dissolving heta-amoxicillin in a mixture of dry inert organic solvent and acetone by addition of triethylamine at a temperature of from -10° to +10° C.; (b) reacting a solution of methoxymethyl p-toluenesulfonate in a dry inert organic solvent with the solution prepared in step (a) at a temperature of from -10° to +10° C.; and (c) recovering the methoxymethyl ester of heta-amoxicillin from the reaction mixture.
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) | 1984-01-27 | 1984-07-28 | 1985-01-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-01-27 | 1988-07-28 | 1989-01-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-01-27 | 1992-07-28 | 1993-01-27 | $7700.00 | Window Closed / Lapsed |