Bromine → Ethyl 4-(3,4-Dimethoxyphenyl)-4-oxo-2-butynoate

Participants

Reaction Steps

The procedure as described above in connection with Intermediate 1 was repeated to prepare ethyl 2,3-dibromo-4-(3,4-dimethoxyphenyl)-4-oxobutanoate (7.3 g, 95%) in the form of a diastereo mixture as a colorless foam (mixing ratio=63:37) from, a solution of ethyl 4-(3,4-dimethoxyphenyl)-4-oxo-2-butenoate (4.8 g, 18 mmol) in methylene chloride (500 ml) and a solution of bromine (1.1 ml) in methylene chloride (100 ml). The diastereo mixture was used in the next reaction without separation.

Provenance & Evidence