反应详情

Sodium hydrogen carbonate (1.68 g, 20.0 mmol) was added to a solution of trans-4-aminomethyl cyclohexanecarboxylic acid methyl ester hydrochloride (2.07 g, 10.0 mmol) obtained in Step 1, 9-fluorenylmethoxycarbonyl isothiocyanate (2.81 g, 10.0 mmol) in chloroform (40 ml) while ice-cooled. The reaction solution was stirred at room temperature for 16 hours, piperidine (5 ml, 50 mmol) was added, and the mixture was stirred at room temperature for further 6 hours. Trans-4-thiouredide methylcyclohexane carboxylic acid methyl ester (1.55 g, 67%) was obtained by concentrating the reaction solution in vacuo and purifying the obtained solid by silica gel column chromatography (ethyl acetate).

1. temperaturecooled
2. stirringthe mixture was stirred at room temperature for further 6 hours