Ethanol → Ethyl 2-(2-thioxo-2,3-dihydrobenzoxazol-5-yl)propionate

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Reaction Steps

A stirred mixture of ethyl 2-(3-amino-4-hydroxyphenyl)propionate (8.4 g.), potassium ethylxanthate (6.33 g.), ethanol (38 ml.) and water (6.5 ml.) was heated under reflux for 4 hours. The solution was evaporated to half volume and diluted with water (65 ml.). The mixture was acidified with 2N-hydrochloric acid and extracted several times with ether. The ethereal solution was washed with water, then dried with anhydrous sodium sulphate, and evaporated to give ethyl 2-(2-thioxo-2,3-dihydrobenzoxazol-5-yl)propionate as an oil. Dry chlorine was passed into a solution of the thione (9 g.) in freshly dried and distilled chloroform (150 ml.) with stirring for 4 hours. The solution was then washed with water, N-sodium hydroxide solution, then water (3x). The dried (Na2SO4) organic solution was evaporated to yield ethyl 2-(2-chloro-5-benzoxazolyl)propionate as a brown oil which was shown to be a single compound by thin layer chromatography.

Provenance & Evidence