Process for making sulfonyl isocyanates

Abstract

PCT No. PCT/US95/08966 Sec. 371 Date Feb. 21, 1997 Sec. 102(e) Date Feb. 21, 1997 PCT Filed Jul. 21, 1995 PCT Pub. No. WO96/06826 PCT Pub. Date Mar. 7, 1996This invention relates to an improved method of making sulfonyl isocyanates from the corresponding sulfonamides and phosgene.

We claim: 
     
       1. In a process for making a compound of the formula   J--SO.sub.2 NCO     wherein   J is ##STR2## by reacting a compound of the formula J--SO 2  NH 2  with phosgene in a reaction mixture comprising the compound J--SO 2  NH 2 , phosgene and a solvent, the improvement comprising conducting the reaction in the presence of a molar excess of phosgene relative to the compound J--SO 2  NH 2 .   
     
     
       2. The process of claim 1 wherein the percent by weight of phosgene in the reaction mixture is at least 2%. 
     
     
       3. The process of claim 2 wherein the percent by weight of phosgene in the reaction mixture is at least 5%. 
     
     
       4. The process of claim 1 wherein J is J-1.