Process for preparing pure 2-methyl-3-(.beta.-hydroxyethylcarbamoyl)quinoxaline 1,4-di-N-oxide, and other compounds similar thereto
AssigneeMarxer S.p.A.
InventorVincenzo Giobbio
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Abstract
The present invention provides a process for preparing high purity 2-methyl-3-(.beta.-hydroxyethylcarbamoyl)quinoxaline 1,4-di-N-oxide, generally involving the following stages carried out separately and in succession: (a) reacting benzofuroxane with an acetacetic acid ester of formula CH.sub.3 --CO--CH.sub.2 --COOR, in the presence of a catalyst in the form of ethanolamine, and in a suitable solvent; (b) separating and isolating the reaction product formed under (a), e.g., 2-methyl-3-(methylcarboxylate)-quinoxaline-1,4-di-N-oxide; and (c) reacting the compound described under (b) with an excess of ethanolamine over the stoichiometric quantity, to give the final carbamoyl derivative.
Claims11
A process for preparing high purity 2-methyl-3-(.beta.-hydroxyethyl-carbamoyl) quinoxaline 1,4-di-N-oxide, comprising the following stages carried out separately and in succession:
- (a) reacting benzofuroxane with an acetacetic acid ester of formula CH.sub.3 --CO--CH.sub.2 --COOR in which R is a C.sub.1 -C.sub.6 alkyl radical, in the presence of a catalyst in the form of ethanolamine, and in a suitable solvent;
- (b) separating and isolating the 2-methyl-3-(alkylcarboxylate)quinoxaline-1,4-di-N-oxide reaction product formed in stage (a);
- and
- (c) reacting the reaction product isolated in stage (b) with an excess of ethanolamine over the stoichiometric quantity to give the carbamoyl derivative.
Dependencies are inferred from the claim text.