Back to results
US 5,847,197 AGranted
Process for the preparation of aminomalonic acid ester salts
AssigneeHuels Aktiengesellschaft
InventorsFrank Bauer, Marcel Feld
Life of this patent
Estimating the term…
Abstract
The invention relates to a process for the preparation of aminomalonic acid esters and optionally their salts by the catalytic hydrogenation of a substituted malonic acid ester in an inert solvent, and optionally by the addition of an acid to the hydrogenation mixture. The process comprises carrying out the hydrogenation in the presence of a solid dehydrating agent and a solvent or solvent mixture in which the aminomalonic acid ester salt is substantially insoluble.
Claims10
A process for preparing an aminomalonic acid ester of the general formula:
- ##STR4## wherein R is a hydrogen, alkyl, cycloalkyl, aryl, alkaryl, or aralkyl moiety;
- R' is an alkyl, cycloalkyl, aryl, alkaryl, or aralkyl moiety;
- and R" is an alkyl, cycloalkyl, aryl, alkaryl, or aralkyl moiety, comprising the steps of:
- (a) providing a reaction mixture including a hydrogenation catalyst, a solid dehydrating agent, an inert solvent, and a substituted malonic acid ester of the general formula:
- ##STR5## wherein R, R', and R" are defined as above;
- and X is a nitro, nitroso, or O-substituted hydroxyimino group;
- and
- (b) catalytically hydrogenating the substituted malonic acid ester, thereby preparing the aminomalonic acid ester.
5 more elements
A process for preparing an aminomalonic acid ester of the general formula:
- ##STR6## wherein R is a hydrogen, alkyl, cycloalkyl, aryl, alkaryl, or aralkyl moiety;
- R' is an alkyl, cycloalkyl, aryl, alkaryl, or aralkyl moiety;
- and R" is an alkyl, cycloalkyl, aryl, alkaryl, or aralkyl moiety, comprising the steps of:
- (a) providing a first reaction mixture including a hydrogenation catalyst, a solid dehydrating agent, an inert solvent, and a substituted malonic acid ester of the general formula:
- ##STR7## wherein R, R', and R" are defined as above;
- and X is a nitro, nitroso, or O-substituted hydroxyimino group;
- (b) catalytically hydrogenating the substituted malonic acid ester in the first reaction mixture, thereby preparing a first quantity of the aminomalonic acid ester;
- (c) removing the dehydrating agent and the catalyst from the first reaction mixture;
- (d) extracting water from the dehydrating agent and the catalyst obtained in step (c);
- (e) providing a second reaction mixture including an inert solvent and the substituted malonic acid ester;
- (f) adding to the second reaction mixture the dehydrating agent or the catalyst obtained in step (d);
- (g) catalytically hydrogenating the substituted malonic acid ester in the second reaction mixture, thereby preparing a second quantity of the aminomalonic acid ester.
9 more elements
Dependencies are inferred from the claim text.