Hydrochloric Acid → HCID 19081730, compound

Participants

Reaction Steps

575 mg of ethyl 1-cyclopropyl-7-[5-(5,5-dimethyl-1,3-dioxan-2-yl)-2,3-dimethoxy-phenyl]-6-fluoro-1,4-dihydro-4-oxo-quinoline-3-carboxylate (Example 7a)) are heated to boiling under reflux in a mixture of 8 ml of a 2N aqueous hydrochloric acid solution and 5 ml of ethanol for 6 hrs. The reaction mixture is cooled in an ice bath and the separated precipitate is filtered off under suction and washed with 20 ml of water and with 50 ml of ether. 330 mg (73%) of 1-cyclopropyl-6-fluoro-7-(5-formyl-2,3-dimethoxy-phenyl)-1,4-dihydro-4-oxo-quinoline-3-carboxylic acid are obtained as a colourless solid. M.p.>230°. Mass spectrum: peaks: inter alia at 411 (M+, 6%), 367 (100%), 338 (6%), 202 (8%), 184 (10%).

Provenance & Evidence