Process for the preparation of 4-hydroxy-quinoline-3-carboxylic acids

Abstract

Abstract A process for the preparation of a compound of the formula ##STR1## in which Y is a nitrile group, an ester group COOR 1 or an acid amide CONR 2 R 3 , R 1 , R 2 and R 3 each independently is hydrogen or C 1 -C 4 -alkyl, and R 3 may also be phenyl, and X 2 , X 3 , X 4 and X 5 each independently is hydrogen, halogen, nitro, cyano, alkyl having 1-3 carbon atoms, alkoxy having 1-3 carbon atoms, alkylmercapto having 1-3 carbon atoms, alkyl-sulphonyl having 1-3 carbon atoms, or a phenylsulphonyl group which is optionally substituted in the aryl radical, comprising reacting an aminoacrylate of the formula in which X 1 is halogen, a nitro group, an alkoxy, alkoxy, alkylmercapto or alkylsulphonyl group having 1-3 carbon atoms in each case, or an arylsulphonyl group, W is hydrogen or a --CH 2 CH 2 Z radical, Z is a nitrile group, an ester group COOR 4 or an acid amide group CONR 5 R 6 , and R 4 , R 5 and R 6 each independently is hydrogen or C 1 -C 4 -alkyl, and R 5 may also be phenyl, with an acid acceptor in an aprotic solvent. Some of the reactants are new, as are the products which are intermediates for antibacterially active 1-alkyl-4-quinolone-3-carboxylic acids.

Inventors

• 👤 Michael Schriewer
• 👤 Klaus Grohe

Bibliographic Details