Phosphorane, ethylidenetriphenyl- → Ethyl alpha-(3,4-dimethoxyphenyl)crotonate

Participants

Reaction Steps

To a diethyl ether solution of ethylidenetriphenylphosphorane prepared in the usual way from 800 g. of ethyltriphenylphosphonium bromide, 400 g. of ethyl 3,4-dimethoxyphenylglyoxylate in 600 ml. of ether are added dropwise. After refluxing for 4-5 hours, the solvent is evaporated and substituted with tetrahydrofuran. The mixture is then heated for 36 hours and then evaporated to dryness and the residue is extracted with diethyl ether in a Soxhlet apparatus giving 150 g. of the title compound. Pursuant to this procedure, the following other α-arylcrotonate starting materials are prepared:

Provenance & Evidence