Method and intermediates for the preparation of derivatives of N-(1-benzhydrylazetidin-3-yl)-N-phenylmethylsulfonamide

1. A process for the preparation of [bis(4-chlorophenyl)methyl]amine, comprising:

a) reacting bis(4-chloro-phenyl)methanone and formamide in the presence of a catalyst, magnesium chloride to form N-[bis-(4-chlorophenyl)methyl]formamide; and

b) deformylating N-[bis-(4-chlorophenyl)methyl]formamide in the presence of HCl in methanol to give [bis(4-chlorophenyl)methyl]amine.

2. A process for the preparation of a compound of formula (IV):

wherein

R and R′ represent, independently of each other, one or more hydrogen, halogen, halogen, cyano, nitro, linear or branched alkyl of 1 to 6 carbon atoms, linear or branched alkoxy of 1 to 6 carbon atoms, linear or branched alkyl carboxylate of 1 to 6 carbon atoms, trifluoromethyl or trifluoromethoxy;

comprising the steps of:

a) reacting a compound of formula (VII)

wherein

R and R′ represent, independently of each other, one or more hydrogen, halogen halogen, cyano, nitro, linear or branched alkyl of 1 to 6 carbon atoms, linear or branched alkoxy of 1 to 6 carbon atoms, linear or branched alkyl carboxylate of 1 to 6 carbon atoms, trifluoromethyl or trifluoromethoxy;

with acetonitrile in the presence of formic acid at a temperature in the range of from about 50° C. to about 150° C., to form a compound of formula (VI):

wherein R and R′ are as defined above;

b) heating the compound of formula (VI) in an acidic medium to form a compound of formula (V) or an acid salt thereof:

wherein R and R′ are as defined above; and

c) converting the compound of formula (V) into the compound of formula (IV) in an organic solvent, n-butanol, and in the presence of anhydrous tripotassium phosphate, an additive, sodium iodide, and, where appropriate, optionally in an aqueous phase.