Phosgene → Ethyl 3-(chloroformyl)carbazate

Participants

Reaction Steps

A one-liter flask is fitted with a gas-dispersion tube, a 500 ml dropping funnel, a stirrer and a condenser fitted with a drying tube. The gas-dispersion tube is connected to a laboratory tank of phosgene on a pan balance. Dry ether, 200 ml, is placed in the flask. The flask is cooled with an ice bath. Phosgene, 115 g (1.2 M) is run into the ether. Ethylcarbazate, 24 g (0.24 M), is added to 500 ml of ether and placed in the dropping funnel. The solution of ethylcarbazate is added slowly and when addition is complete, the reaction is allowed to stir overnight. The solution is filtered and the solvent and excess phosgene removed with a vacuum pump fitted with a dry-ice trap. The trapped phosgene is destroyed by addition to a mixture of NaHCO3 solution and ice. The product is a white powder which is redissolved in ether and filtered. The ether is evaporated resulting in a crystalline white solid weighing 38 g, mp 77°-80°.

Provenance & Evidence