反应详情

温度

10 °C

Ethyl 4-dimethylamino-2-oxo-3-butenoate (675 g) is added in the course of 3 hours, while the temperature is maintained at approximately 10° C., to a solution, cooled to 10° C. and through which a stream of argon is passed, of triethyloxonium tetrafluoroborate (862 g) in methylene chloride. The reaction medium is then stirred for 5 hours at a temperature in the region of 20° C. The solution of N-(3-ethoxy-3-ethoxycarbonylpropenylidene)-N-methylmethanaminium tetrafluoroborate thereby obtained is stored under an argon atmosphere, and is used immediately in the subsequent syntheses.

1. temperaturecooled to 10° C. and through which a stream of argon