Process for preparing acylsulfamoylbenzamides

A process for the preparation of a compound of formula (I):

• wherein:
• R1 is hydrogen, —(CH2)p-heterocyclyl or a hydrocarbon radical, where the two last-mentioned radicals are unsubstituted or substituted by one or more radicals selected from the group consisting of halogen, (C1-C6)-alkyl, (C1-C6)-haloalkyl, (C1-C6)-alkoxy, cyano and nitro;
• R2 is hydrogen, (C1-C6)-alkyl, (C2-C6)-alkenyl, (C2-C6)-alkynyl, (C1-C6)-alkoxy, (C2-C6)-alkenyloxy, where the five last-mentioned radicals are unsubstituted or substituted by one or more radicals selected from the group consisting of halogen, (C1-C4)-alkoxy and (C1-C4)-alkylthio;
• or R1 and R2 together with the linking nitrogen atom form a 3- to 8-membered saturated or unsaturated ring;
• R3 and R5 are each independently halogen, (C1-C6)-alkyl, (C1-C6)-haloalkyl, (C1-C6)-alkoxy, S(O)q—(C1-C6)-alkyl, (C1-C6)-alkylcarbonyl, —CO-aryl, cyano or nitro;
• or two adjacent R5 groups form a —O—CH2CH2— moiety;
• R4 is hydrogen, (C1-C4)-alkyl, (C2-C4)-alkenyl or (C2-C4)-alkynyl;
• n is an integer from 0 to 4;
• m is an integer from 0 to 5;
• p is 0 or 1;
• and
• q is 0, 1 or 2;
• or a salt thereof;
• which process comprises the reaction of a compound of formula (II):
• wherein R3, R4 and n are as defined in formula (I), with a compound of formula (III):
• wherein R5 and m are as defined in formula (I) and Y is OH or Cl, in the presence of a chlorinating agent, to give a compound of formula (IV):
• wherein R3, R4, R5, m and n are as defined in formula (I), followed by the reaction of the resultant compound of formula (IV) with a compound of formula (V):
• R1R2NH (V)
• wherein R1 and R2 are as defined in formula (I), in the presence of a base.