4-hydroxy-2-quinolones. 204.* synthesis, bromination, and analgetic properties of 1-allyl-4-hydroxy- 6,7-dimethoxy-2-oxo-1,2-dihydroquinoline-3-carboxylic acid arylalkylamides

A simple method has been proposed and used for the preparation of 1-allyl-4-hydroxy-6,7-dimethoxy-2-oxo-1,2-di-hydroquinoline-3-carboxylic acid arylalkylamides. Similar to alkylamides of this acid, the arylalkylamides obtained are halogenated with cyclization by one equivalent of molecular bromine to give the corresponding 2-bromomethyl-7,8-dimethoxy-5-oxo-1,2-dihydro-5H-oxazolo[3,2-a]quinoline-4-carbox-amides. However, the reaction proceeds quite differently when using an excess of bromine. After the usual initial oxazole ring closure, the excess bromine brominates the aromatic ring of the amide fragment. The results of testing for the analgesic activity of these products are presented.