反应详情

A mixture of 2-hydoxy-4,5-methylenedioxybenzaldehyde (1.16 g), diethyl malonate (1.34 g), piperidine (0.3 g), acetic acid (0.035 ml) and ethanol (30 ml) was refluxed for 4 hours. After the reaction mixture was cooled, the resulting crystal was collected by filtration to yield ethyl 6,7-methylenedioxy-2-oxo-1-benzopyran-3-carboxylate (1.29 g, 70%) having a melting point of 200°-201° C.

1. temperaturewas refluxed for 4 hours
2. temperatureAfter the reaction mixture was cooled
3. filtrationthe resulting crystal was collected by filtration