Patent ID: 7045662

Claim:
A process for preparing at least one compound of the formula (I) wherein R 1 represents hydrogen, C 1 –C 12 -alkyl, [(C 2 –C 12 -alkylene)-O] n (C 1 –C 12 -alkyl)] where n=1 to 5, C 3 –C 14 -aryl, C 4 –C 15 -arylalkyl or NR 4 R 5 , where R 4 and R 5 each independently of one another represent C 1 –C 8 -alkyl or NR 4 R 5 as a whole represents a 4 to 7-membered cyclic radical having a total of 3 to 16 carbon atoms and R 2 and R 3 each independently of one another represent C 1 –C 12 -alkyl, C 3 –C 14 -aryl or C 4 –C 15 -arylalkyl, or together are part of a cyclic radical having a total of 3 to 16 carbon atoms, or R 1 and R 2 and/or R 3 are a cyclic radical having a total of 3 to 16 carbon atoms; comprising reacting compounds of the formula (II) wherein R 1 , R 2 and R 3 have the meanings given above in the presence of oxalyl fluoride or a mixture of oxalyl fluoride and difluorophosgene.