Patent ID: 8188290

Claim:
A process for preparing N,N-substituted carbamoyl halides of formula (I) (R 1 )(R 2 )NC(O)X wherein X is bromine or chlorine, and R1 is 1-(3,5-bis-trifluoromethyl phenyl)-ethyl, R2 is methyl, or R1 and R2, together with the nitrogen to which they are attached, form 2-(4-Fluoro-2-methyl-phenyl)-piperidine-4-one, which comprises the following steps: a) contacting carbon dioxide and a secondary amine selected from [1-(3,5-bis-trifluoromethyl phenyl)-ethyl]methyl amine, 2-(4-Fluoro-2-methyl-phenyl)piperidine-4-one and enantiomers thereof in the presence of an organic solvent and a base under conditions of time and temperature sufficient to produce the corresponding carbamate salt (III) (R 1 )(R 2 )NC(O)O— (b) reacting the carbamate salt (III) with trialkylsilylchloride under conditions of time and temperature sufficient to produce the corresponding trialkylsilylester carbamic acid (IV) (R 1 )(R 2 )NC(O)OSi(Alkyl) 3 and (c) reacting the trialkylsilylester carbamic acid (IV) with a halogenating agent under reaction conditions of time and temperature sufficient to produce the corresponding N,N-substituted carbamoyl halide of formula (I) (R 1 )(R 2 )NC(O)X wherein X is bromine or chlorine.