Preparation of 2-phenyl-4,5-dihydro-oxazole-5-carboxylic acid derivatives, used as intermediates, by catalytic cyclization of N-benzoyl-aminoalkene compound

摘要

A 2-phenyl-4,5-dihydro-oxazole-5-carboxylic acid compound is prepared by cyclizing an N-benzoyl-aminoalkene using palladium catalyst to produce 2-phenyl-5-ethenyl-oxazoline compound and oxidizing Preparation of a 2-phenyl-4,5-dihydro-oxazole-5-carboxylic acid of formula (I) comprises cyclizing an N-benzoyl-aminoalkene of formula (IV) using a palladium compound as a catalyst to produce a 2-phenyl-5-ethenyl-oxazole compound of formula (III); and oxidizing (III) using an oxidizing agent and a mixed solvent of acetonitrile/carbon tetrachloride/water to obtain (I). R = sec-butyl thiomethyl, cyclohexylmethyl, p-hydroxyphenylmethyl; X = halide; Bz = Benzoyl.