Yield:612541-12-5 11%

Reaction Conditions:

with chlorosulfonic acid at 0 - 20;

Steps:

I-2.1 2-Methoxy-5-trifluoromethylbenzenesulfonyl chloride

To chloro sulfuric acid (15 mL) was added l-methoxy-4-trifluoromethyl- benzene (3.0 g, 17 mmol) portionwise at 0°C. The mixture was stirred at room temperature overnight. The mixture was poured into ice. the aqueous layer was extracted with EtOAc (50 mL x3). The extracts were dried over Na₂S0₄ and the solution was filtered through a pad of silica gel, dried in vacuum to afford 500 mg (yield: 11%) of 2-methoxy-5-trifluoromethyl- benzenesulfonyl chloride as white solid. [00183] 1H NMR (DMSO-d6): δ = 7.90 (1H, d), 7.67 (1H, dd), 7.18 (1H, d), 3.84 (3H, s).

References:

WO2013/126608,2013,A1 Location in patent:Paragraph 00182-00183