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US4335256A
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Process for manufacturing d,l-β-benzoylamino-isobutyric acid
Assignee: Sigma Tau Industrie Farmaceutiche Riunite SpA
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Filing: 1978-11-16
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Granted: 1982-06-15
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Expires: 1998-11-16
Abstract
Abstract A two-step process for manufacturing d,l-β-benzoylamino-isobutyric acid is disclosed, wherein in the first step benzamide is reacted with methacrylonitrile in the presence of an alkaline catalyst in an anhydrous solvent medium at atmospheric pressure, thus obtaining d,l-β-benzoylamino-isobutyronitrile, which, in the second process step, without necessarily being previously crystallized is directly hydrolyzed to d,l-β-benzoylamino-isobutyric acid.
Inventors
- 👤 Paolo de Witt
- 👤 Enrico Diamanti
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 20:09
CPC Classifications
C; C07; C07C; C07C231/00; C07C231/12; C07C253/00; C07C253/30
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
121 words
In a process for preparing d,l-β-benzoylamino-isobutyric acid, having the formula ##STR3## which comprises: (a) reacting benzamide with methacrylonitrile in the presence of an alkaline catalyst in an anhydrous solvent medium, at a temperature of about 80° to 100° C., thus obtaining d,l-β-benzoylamino-isobutyronitrile, having the formula: ##STR4## (b) hydrolyzing said d,l-β-benzoylamino-isobutyronitrile to d,l-β-benzoylamino-isobutyric acid in an alkaline medium in the presence of a lower alkanol having from 1 to 4 carbon atoms at a temperature of about 40° to 60° C., the improvement wherein the reaction of said benzamide with methacrylonitrile is carried out in the presence of an alkaline catalyst which is a quaternary ammonium base selected from the group consisting of benzyl-trimethylammonium hydroxide, benzyl-triethyl-ammonium hydroxide, tetrabutylammonium hydroxide and mixtures thereof.
Claim 2
Dependent Claim
121 words
In a process for preparing d,l-β-benzoylamino-isobutyric acid, having the formula ##STR3## which comprises: (a) reacting benzamide with methacrylonitrile in the presence of an alkaline catalyst in an anhydrous solvent medium, at a temperature of about 80° to 100° C., thus obtaining d,l-β-benzoylamino-isobutyronitrile, having the formula: ##STR4## (b) hydrolyzing said d,l-β-benzoylamino-isobutyronitrile to d,l-β-benzoylamino-isobutyric acid in an alkaline medium in the presence of a lower alkanol having from 1 to 4 carbon atoms at a temperature of about 40° to 60° C., the improvement wherein the reaction of said benzamide with methacrylonitrile is carried out in the presence of an alkaline catalyst which is a quaternary ammonium base selected from the group consisting of benzyl-trimethylammonium hydroxide, benzyl-triethyl-ammonium hydroxide, tetrabutylammonium hydroxide and mixtures thereof.
Claim 3
Dependent Claim
23 words
The process of claim 1, wherein said anhydrous solvent medium is selected from the group consisting of dioxane, tetrahydrofuran, dimethylsulfoxide and mixtures thereof.
Claim 4
Dependent Claim
38 words
The process of claim 1, wherein said alkaline medium is selected from a solution of an alkaline reagent of the group consisting of Na 2 CO 3 , K 2 CO 3 , NaOH, KOH and mixtures thereof.
Claim 5
Dependent Claim
26 words
The process of claim 1 wherein said alkaline medium is a solution of an alkali metal hydroxide or carbonate in a concentration of about 0.5-2 N.
Claim 6
Dependent Claim
15 words
The process of claim 1, wherein said lower alkanol having 1-4 carbon atoms is methanol.
Claim 7
Dependent Claim
17 words
The process of claim 1, wherein step (a) is carried out substantially in the absence of light.
Claim 8
Dependent Claim
20 words
The process of claim 1, which comprises, before hydrolysis, subjecting d,l-β-benzoylamino-isobutyronitrile of step (a) to washing with methyl t-butyl ether.
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) | 1985-06-14 | 1985-12-14 | 1986-06-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1989-06-14 | 1989-12-14 | 1990-06-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1993-06-14 | 1993-12-14 | 1994-06-15 | $7700.00 | Window Closed / Lapsed |