4-Toluenesulfonyl chloride → 6-Chloro-4-(1-ethoxycarbonyl-piperidin-4-ylamino)2-oxo-1,2-dihydro-quinoline-3-carboxylic acid methyl ester

Participants

Reaction Steps

To a suspension of 6-Chloro-4-hydroxy-2-oxo-1,2dihydro-quinoline-3-carboxylic acid methyl ester (445 mg, 1.8 mmol) and diisopropylethlyamine (607 uL, 3.5 mmol) in acetonitrile (30 mL) was added p-toluenesulfonyl chloride (400 mg, 2.1 mmol). The reaction was stirred at room temperature and monitored by TLC to completion (2 h). 4-amino-piperidine-1-carboxylic acid ethyl ester was then added to the reaction mixture which was stirred at 50° C. for 8 h. The reaction mixture was then diluted up with CH2Cl2 and washed with water. The organic portion was dried with MgSO4 and evaporated. The residue was purified by flash chromatography through a silica gel column with dichloromethane and methanol (95:5 v/v) to provide a white solid (235 mg, 32%) which was carried onto the next step without characterization.

Provenance & Evidence