Process for the preparation of sulfonylurea based compounds

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

• wherein
• B is selected from a ring system selected from:
• wherein each X1, Y, and Z is independently selected from C, N, S, SO2, and O, each of which may be optionally substituted;
• each R1 is independently selected from hydrogen, halogen, haloalkyl, and optionally substituted (C1-C6)alkyl;
• each R2 is independently selected from hydrogen, halogen, haloalkyl, and optionally substituted groups selected from (C1-C6)alkyl;
• R3 and R4 are each hydrogen;
• X is selected from N—R5;
• O, S, and SO2;
• each R5 is independently selected from hydrogen, halogen, haloalkyl, cyano, (C1-C6)alkyl, (C1-C6)haloalkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, (C1-C6)alkoxy, (C3-C7)cycloalkyl, (C1-C6)alkylSO2(C1-C6)alkyl, (C1-C6)alkylN(C1-C6)alkyl, (C1-C6)alkylN(C3-C7)cycloalkyl, aryl, heteroaryl, heterocyclyl, benzyl, thiol, mercaptoalkyl, SO2(C1-C6)alkyl, SO2(C3-C7)cycloalkyl, SO2-aryl, SO2-heterocyclyl, (C1-C6)thioalkyl, (C1-C6)thioalkoxy, (C1-C6)alkylSO2NH2, —CONH2, —CO(C1-C6)alkyl, —CO(C1-C6)haloalkyl, —CO-aryl, —CO— heteroaryl, —CO-heterocyclyl, 4- to 7-membered heterocyclyl, 7- to 14-membered bicyclic heterocyclyl, and a bridged or spiro ring system having optionally one or more than one heteroatoms, wherein the (C1-C6)alkyl, (C1-C6)haloalkyl, (C2-C6)alkenyl, (C2-C6)alkynyl, (C1-C6)alkoxy, (C3-C7)cycloalkyl, (C1-C6)alkylSO2(C1-C6)alkyl, (C1-C6)alkylN(C1-C6)alkyl, (C1-C6)alkylN(C3-C7)cycloalkyl, aryl, heteroaryl, heterocyclyl, benzyl, thiol, mercaptoalkyl, SO2(C1-C6)alkyl, SO2(C3-C7)cycloalkyl, SO2-aryl, SO2-heterocyclyl, (C1-C6)thioalkyl, (C1-C6)thioalkoxy, (C1-C6)alkylSO2NH2, —CONH2, —CO(C1-C6)alkyl, —CO(C1-C6)haloalkyl, —CO-aryl, —CO-heteroaryl, —CO-heterocyclyl, 4- to 7-membered heterocyclyl, 7- to 14-membered bicyclic heterocyclyl, or the bridged or spiro ring system having optionally one or more than one heteroatoms are optionally substituted;
• Each of R6, R7, R8, R9, R10 and R11 is independently selected from hydrogen, halogen, optionally substituted (C1-C6)alkyl, and optionally substituted (C1-C6)haloalkyl,
• the process comprising the steps:
• Step 1) reacting a compound of formula (II)
• with thionyl chloride in the presence of one or more solvents to obtain a compound of formula (III);
• wherein R is an ester group;
• Step 2) reacting the compound of formula (III) with 1-bromo-3-chloropropane in the presence of base and one or more solvents to obtain a compound of formula (IV):
• Step 3) reacting the compound of formula (IV) with Boc anhydride in presence of base to obtain a compound of formula (V)
• Step 4) dissolving the compound of formula (V) in one or more solvents in presence of base to obtain a compound of formula (VI):
• Step 5) dissolving the compound of formula (VI) in one or more solvents in the presence of a suitable base to obtain a compound of formula (VII):
• Step 6)
• reacting the compound of formula (VII) with isobutyl chloroformate in the presence of base and one or more solvents to obtain a filtrate;
• and
• adding the filtrate to a reaction mixture comprising sodium borohydride dissolved in one or more solvents to obtain a compound of formula (VIII):
• Step 7) reacting the compound of formula (VIII) with an oxidizing agent in the presence of one or more solvents to obtain a compound of formula (X):
• Step 8) dissolving the compound of formula (X) in a solution mixture comprising a compound of formula (IX):
• dissolved in one or more solvents in presence of base to obtain a compound of formula (XI):
• Step 9) dissolving the compound of formula (XI) in one or more solvents and heating the solution at a suitable temperature to obtain a compound of formula (XII);
• Step 10) dissolving a compound of formula (XIII):
• in one or solvents to form a solution comprising the compound of formula (XIII):
• and adding the solution comprising a compound of formula (XIII) to a solution comprising the compound of formula (XII) dissolved in one or more solvents in the presence of base to obtain a compound of formula (XIV):
• wherein the solution comprising the compound of formula (XIII) is added dropwise
• Step 11) reacting the compound of formula (XIV) with a reagent in the presence of one or more solvents to obtain a compound of formula (XV):
• and
• Step 12) reacting the compound of formula (XV) with a reagent in the presence of one or more solvents and a base to form a reaction mixture comprising a compound of formula (XV);
• and adding one or more reagents to the reagent mixture comprising a compound of formula (XV) to obtain a compound of formula (I).