Process for the preparation of Canagliflozin

A process for the preparation of canagliflozin comprising:

• a) reacting (5-bromo-2-methylphenyl) [5-(4-fluorophenyl) thiophen-2-yl] methanone with a tri alkyl orthoformate or tri alkyl orthoaceatate, optionally in the presence of acid, to produce 2-[(5-bromo-2-methylphenyl)(dimethoxy)methyl]-5-(4-fluorophenyl)thiophene;
• b) (i) reacting 2-[(5-bromo-2-methylphenyl)(dimethoxy)methyl]-5-(4-fluorophenyl)thiophene with magnesium and iodine at about 25° C. to about 30° C. to form a Grignard reagent, and (ii) condensing the resulting Grignard reagent with 2,3,5,6 tetrakis-O-trimethylsilyl-D-glucanolactone to produce dimethoxy-[5-(4-fluorophenyl)-thiophen-2-yl]-[2-methyl-5-(2-hydroxy-3,4,5-trimethylsilyloxy-6-trimethylsilyloxymethyl-tetrahydro-pyran-2-yl)-phenyl]-methane;
• c) deprotecting dimethoxy-[5-(4-fluorophenyl)-thiophen-2-yl]-[2-methyl-5-(2-hydroxy-3,4,5-trimethylsilyloxy-6-trimethylsilyloxymethyl-tetrahydro-pyran-2-yl)-phenyl]-methane in the presence of an acid and an alcohol solvent to produce [5-(4-fluorophenyl)-thiophen-2-yl]-[2-methyl-5-(3,4,5-trihydroxy-6-hydroxymethyl-2-methoxy-tetrahydro-pyran-2-yl)-phenyl]-methanone;
• and
• d) reducing [5-(4-fluorophenyl)-thiophen-2-yl]-[2-methyl-5-(3,4,5-trihydroxy-6-hydroxymethyl-2-methoxy-tetrahydro-pyran-2-yl)-phenyl]methanone with a trialkyl silane and a Lewis acid, wherein the Lewis acid is selected from boron trichloride, boron tribromide, diborane, boron trifluoride, and complexes thereof, to produce canagliflozin.