Potassium Hydroxide → HCID 13491392, compound

Participants

Reaction Steps

900 mg of ethyl 9,10-difluoro-3-methylene-7-oxo-2,3-dihydro-7H-pyrido(1,2,3-de)-1,4-benzoxazine-6-carboxylate was suspended in 20 ml of ethanol and 5 ml of an aqueous solution containing 500 mg of potassium hydroxide was added thereto. The resulting mixture was allowed to react for 3 hours at 50°-60° C. (bath temperature). The solvent was distilled off and 10 ml of water was added to the residue and the mixture was neutralized by addition of hydrochloric acid. The precipitate formed was collected by filtration and washed with water and then dried to give 810 mg of 9,10-difluoro-3-methylene-7-oxo-2,3-dihydro-7H-pyrido-(1,2,3-de)-1,4-benzoxazine-6-carboxylic acid as a white powder. The powder was recrystallized from ethanol to give fine needles with mp 273°-276° C. (decomposition).

Provenance & Evidence