Methanethioamide → 4-(6-Carbomethoxy hexyl)-thiazole-5-carboxylic acid methylester

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Reaction Steps

16.8 g of 9-carbomethoxy-2-chloro-3ketonononoic acid methylester (VI) and 4.5 of thioformamide (VII, R1 = H) were refluxed in 90 ml of methanol for 1 hour, then methanol was evaporated in vacuo, and the distillation residue was dissolved in 150 ml of 2 N hydrochloric acid. The obtained solution was neutralized with a 5 % solution of sodium carbonate, saturated with ammonium sulphate and extracted with 3 × 150 ml of diethyl ether. The ethereal extract was dried over sodium sulphate, then ether was evaporated. Thus 16 g of crude 4-(6-carbomethoxyhexyl)-thiazole-5-carboxylic acid methylester (VIII, R1 = H) were obtained which could be used without any further purification for the preparation of 4-(6-carboxyhexyl)-thiazole-5-carboxylic acid (IX, R1 = H) according to point (e).

Provenance & Evidence