Methyl chloroformate → Thiophamine

Participants

Reaction Steps

Methyl chloroformate (23.6 g; 0.25 mole) was added dropwise to a stirred suspension of potassium thiocyanate (24.2 g; 0.25 mole) in dry acetonitrile (100 ml). The temperature of the reaction mixture rose spontaneously to 50° C. and stirring was continued for two hours at 45° C. to 50° C. The reaction mixture was then filtered and the clear filtrate was added dropwise during fifteen minutes to a suspension of o-phenylenediamine (27 g; 0.25 mole) in dry acetonitrile (20 ml), the temperature during the addition being maintained between 15° C. and 20° C. by external cooling. When the addition was complete, the reaction mixture was stirred at laboratory temperature for two hours, filtered, and the crude solid product was crystallised from ethanol to give colourless needles of 1-methoxycarbonyl-3-(2-aminophenyl)-thiourea (15.3 g), m.p. 183.5°-184.5° C. (with decomposition).

Provenance & Evidence