Phosgene → o-N,N-Diethylsulfamoylbenzenesulfonyl isocyanate

Participants

Reaction Steps

A solution of 13.2 g of N,N-diethyl-1,2-benzenedisulfonamide, 4.5 g of n-butylisocyanate, and 0.2 g of 1,4-diaza[2,2,2]bicyclooctane (DABCO) in 90 ml of mixed xylenes was heated to 135°. To this solution was added 3.3 ml of liquid phosgene at such a rate that the temperature was maintained between 125 and 135° (about 2 hours). The temperature was kept at 130° for 1/2 hour after the addition. The solution was cooled and filtered to remove a small amount of insoluble solid then concentrated at 60°-70° in-vacuo. The residue of o-N,N-diethylsulfamoylbenzenesulfonyl isocyanate was an oil weighing 16.8 g and was sufficiently pure for further reaction.

Provenance & Evidence