3,4-Dimethoxy-2-(trifluoromethyl)benzoic acid synthesis

Yield:1338709-29-7 85%

Reaction Conditions:

with sodium chlorite;SULFAMIDE in methanol;water; for 2 h;Cooling with ice;

Steps:

146.1 Step (1): Compound iii-13a → Compound iii-13b

Amide sulfuric acid (8.53 g, 88 mmol) and water (60 mL) were added to a solution of compound iii-13a (5.88 g, 25.1mmol, synthesized with reference to a method described in J. Med. Chem., 1992, 35, 466-479) inmethanol (80 mL). The resultant solution was stirred while cooled with ice. To the solution was added sodium chlorite (7.95 g, 88 mmol). While cooled with ice, the solution was stirred for 2 hour, and then thereto was dropwise added a solution of sodiumhydrogensulfite (13.06 g, 126 mmol) in water (100 mL). The precipitated solid was then collected by filtration, and washed with water to yield compound iii-13b (5.33 g, 85%).¹H-NMR (DMSO-d₆) δ: 7.38 (1H, d, J= 8.56 Hz), 7.30 (1H, d, J= 8.56 Hz), 3.90 (3H, s), 3.82 (3H, s).

References:

EP2557082,2013,A1 Location in patent:Paragraph 0533; 0534