N,N'-Dicyclohexylurea → 1-(2-Methylthiazole-5-carbonyl)-2-cyanoaziridine

Participants

Reaction Steps

1.6 g. 2-Methylthiazole-5-carboxylic acid (m.p. 209° C.) and 0.76 g. 2-cyanoaziridine in 20 ml. tetrahydrofuran are mixed at 0° to 5° C. with 2.4 g. dicyclohexylcarbodiimide. The reaction mixture is stirred for 1 hour at 0° C. and for 3 hours at ambient temperature, whereafter the precipitated dicyclohexylurea is filtered off with suction and washed with the above-mentioned solvent and with diethyl ether. The filtrate is evaporated in a vacuum and the evaporation residue is taken up in ethyl acetate and shaken out with a saturated aqueous solution of sodium bicarbonate. The organic phase is dried and evaporated in a vacuum to give 2.38 g. of an oil. This oily residue is dissolved in 90 ml. diethyl ether, left to stand overnight, precipitated dicyclohexylurea is filtered off with suction, the ethereal solution is evaporated and the evaporation residue is triturated with a little diethyl ether, 1.4 g. 1-(2-methylthiazole-5-carbonyl)-2-cyanoaziridine being obtained; m.p. 90°- 92° C.

Provenance & Evidence