Patent US4284782A successfully refreshed from Google Patents.
US4284782A
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Process for the manufacture of 6-hydroxypyrid-2-ones
Assignee: Sanofi Aventis Deutschland GmbH
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Filing: 1979-09-17
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Granted: 1981-08-18
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Expires: 1999-09-17
Abstract
Abstract The manufacture of 6-hydroxypyrid-2-ones is achieved by reacting a cyanoacetamide with an acetoacetic acid ester at temperatures of 50° to 200° C. and a pressure of 0.5 to 50 bars in an aqueous solution or suspension in the presence of an amine in a molar amount at least equal to that of the cyanoacetamide reactant.
Inventors
- 👤 Frank Schmidt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 09:14
CPC Classifications
C; C07; C07D; C07D213/00; C07D213/02; C07D213/04; C07D213/60; C07D213/78; C07D213/84; C07D213/85
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
153 words
In the process for the manufacture of 6-hydroxypyrid-2-ones of the formula ##STR6## wherein R is hydrogen or alkyl having 1 to 4 carbon atoms comprising reacting a cyanoacetamide of the formula ##STR7## with an acetoacetic acid ester of the formula ##STR8## wherein R 1 is selected from the group consisting of alkyl having 1 to 8 carbon atoms, alkenyl having 1 to 8 carbon atoms, cycloalkyl having 3 to 6 carbon atoms and cycloalkenyl having 3 to 6 carbon atoms, at elevated temperatures in an aqueous solution or suspension in the presence of a basic compound in a molar amount at least equal to that of said cyanoacetamide, the improvement comprises said basic compound being an amine of the formula RNH 2 with R being the identical to the pyridone nitrogen substituent, and the reaction is carried out at temperatures from 50° to 200° C. at superatmospheric pressure of 0.5 to 50 bars.
Claim 2
Dependent Claim
153 words
In the process for the manufacture of 6-hydroxypyrid-2-ones of the formula ##STR6## wherein R is hydrogen or alkyl having 1 to 4 carbon atoms comprising reacting a cyanoacetamide of the formula ##STR7## with an acetoacetic acid ester of the formula ##STR8## wherein R 1 is selected from the group consisting of alkyl having 1 to 8 carbon atoms, alkenyl having 1 to 8 carbon atoms, cycloalkyl having 3 to 6 carbon atoms and cycloalkenyl having 3 to 6 carbon atoms, at elevated temperatures in an aqueous solution or suspension in the presence of a basic compound in a molar amount at least equal to that of said cyanoacetamide, the improvement comprises said basic compound being an amine of the formula RNH 2 with R being the identical to the pyridone nitrogen substituent, and the reaction is carried out at temperatures from 50° to 200° C. at superatmospheric pressure of 0.5 to 50 bars.
Claim 3
Dependent Claim
31 words
The process according to claim 1, wherein R 1 is selected from the group consisting of alkyl having 1 to 8 carbon atoms and cycloalkyl having 3 to 6 carbon atoms.
Claim 4
Dependent Claim
31 words
The process according to claim 1, wherein R 1 is selected from the group consisting of alkyl having 1 to 8 carbon atoms and cycloalkyl having 5 to 6 carbon atoms.
Claim 5
Dependent Claim
17 words
The process according to claim 1, wherein R 1 is alkyl having 1 to 4 carbon atoms.
Claim 6
Dependent Claim
34 words
The process according to claim 1, wherein the cyanoacetamide is the crude reaction product obtained by reacting a cyanoacetic acid ester of the formula ##STR9## with an amine of the formula RNH 2 .
Claim 7
Dependent Claim
28 words
The process according to claim 1 wherein the reaction pressure is the total of the partial pressures of the constituents of the reaction mixture at the reaction temperature.
Claim 8
Dependent Claim
16 words
The process according to claim 1, wherein the reaction temperature is between 80° and 120° C.
Claim 9
Dependent Claim
13 words
The process according to claim 1, wherein R is hydrogen, methyl or ethyl.
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) | 1984-08-17 | 1985-02-16 | 1985-08-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-08-17 | 1989-02-16 | 1989-08-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-08-17 | 1993-02-16 | 1993-08-18 | $7700.00 | Window Closed / Lapsed |