Process for the preparation of

1. An improved process for the preparation of an N-([1,2,4]triazolopyrimidin-2-yl)aryl sulfonamide of formula I:

wherein

X represents CH or N;

Y represents CZ or N with the proviso that only one of X or Y is N;

W represents H or OR with the proviso that when Y represents CZ, then W represents H;

Z represents OR;

R represent CH 3 or CH 2 CH 3 ;

Ar represents

wherein

A and B independently represent H, halo, CF 3 , R or OR 1 ;

D represents H, halo or R;

E and G represent S or CB with the proviso that one of E or G is S; and

R 1 represents C 1 -C 4 alkyl, C 3 -C 4 alkenyl, or C 3 -C 4 alkynyl each optionally possessing up to two chloro, bromo or C 1 -C 4 alkyl substituents or up to the maximum possible number of fluoro substituents

which comprises combining a sulfonyl chloride compound of the formula:

ArSO 2 Cl

wherein

Ar is defined as above

with an amine compound of the formula:

wherein

R, X, Y and W are defined as above

in the presence of an aromatic tertiary amine base and a catalytic amount of an N-aryl-sulfilimine compound of the formula:

wherein

R, X, Y and W are defined as above;

R 2 represents CH 3 , or CH 2 CH 3 ; and

R 3 represents R 2 or R 2 and R 3 together represent tetramethylene or their salts,

wherein the improvement comprises using 3-picoline or 3,5-lutidine as the aromatic tertiary amine base.

2. The process of claim 1 which R 2 and R 3 each represent CH 3 .

3. The process of claim 1 in which the N-arylsulfilimine compound is in the form of the HCl or HBr salt.