Formaldehyde → HCID 19072254, compound

Participants

Reaction Conditions

Reaction Steps

2.64 g of ethyl 1-cyclopropyl-7-diphenylmethoxycar-bonylmethyl-6-fluoro-8-methoxy-1,4-dihydro-4-oxo-3-quino-linecarboxylate was suspended in 20 ml of dimethylsulfoxide. Then 0.85 g of a 35% aqueous solution of formaldehyde and 21 mg of sodium hydrogencarbonate were added thereto and the mixture was stirred at 50° C. for 1.5 hours. To the reaction mixture, 100 ml of ethyl acetate and 50 ml of water were added and then the organic layer was collected. The organic layer thus collected was successively washed with water and a saturated aqueous solution of sodium chloride and dried over anhydrous sodium sulfate. After removing the solvent under reduced pressure, the obtained residue was dissolved in 25 ml of methylene chloride. Under ice-cooling, 0.57 g of methanesulfonyl chloride and 1.0 mg of triethylamine were successively dropped thereinto slowly and the resulting mixture was stirred at room temperature for 3 hours. 20 ml of water was added to the reaction mixture and the pH value of the mixture was regulated to 1 with 2N hydrochloric acid. Then the organic layer was collected, successively washed with water and a saturated aqueous solution of sodium chloride and dried over anhydrous sodium sulfate. After removing the solvent under reduced pressure, the oily product thus obtained was crystallized by adding ethanol and the crystals were collected by filtration. Thus 1.98 g of ethyl 1-cyclopropyl-7-(1-diphenylmethoxycarbonylvinyl)-6-fluoro-8-methoxy-1,4-dihydro-4-oxo-3-quinolinecarboxylate was obtained (yield: 73.1%).

Provenance & Evidence