2-Phenyl-5-dimethyl-(5, 4)-dihydro-oxazole-4-carboxylic Acidの合成

Abstract

Dimethylacrylic acid was used as the material which, together with Br2, were dropped into methanol under the presence of AgNO3 to give (I). This was treated with 28% NH4OH in a sealed tube by heating to 90-100° to give (II). The methyl ester of (II) was prepared into benzoyl derivative (III) with benzoyl chloride in an ordinary manner.This benzoyl derivative was heated over a water bath with POCl3 in anhydrous benzene solution and methyl 2-phenyl-5-dimethyl-(5, 4)-dihydro-oxazole-4-carboxylate (IV) was obtained as the cyclized product.Saponification of this ester with 2% alcoholic potash gave the corresponding carboxyli cacid (V).Application of P2S5 to (IV) to obtain the corresponding sulfur compound, 2-phenyl-5-dimethy-(5, 4)-dihydrothiazole-4-carboxylic acid (VI), was attempted but ended unsuccessfully.