4-Methoxybenzoic Acid → N,N'-Dicyclohexylurea

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Reaction Steps

1.52 g. p-Methoxybenzoic acid is dissolved in 20 ml. dioxan and mixed at 10° C. with a solution of 0.68 g. 2-cyanoaziridine in 3 ml. dioxan. A solution of 2.06 g. dicyclohexylcarbodiimide in 4 ml. dioxan is added thereto and the reaction mixture is stirred for 2 hours at 8°-10° C. The crystals formed (2 g. 1,3-dicyclohexylurea; m.p. 225°-230° C.) are filtered off with suction and the filtrate is evaporated in a vacuum. The semi-solid evaporation residue (3.88 g.) is triturated with 3 ml. anhydrous diethyl ether, the crystals obtained (0.6 g.) are filtered off with suction, the filtrate is evaporated in a vacuum and the evaporation residue (2.45 g.) is again triturated with 3-4 ml. diethyl ether and filtered with suction to give 0.59 g. 1-p-methoxybenzoyl-2-cyanoaziridine; m.p. 81°-83° C. A further 0.18 g. of the desired product are obtained from the mother liquor by again evaporating and triturating the evaporation residue with diethyl ether.

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