Hydrochloric Acid → 5-[3-(4-Trifluoromethyl-phenyl)-benzo[d]isothiazol-6-yl]-pent-4-yn-1-ol

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Reaction Steps

To 3.3 g (7.72 mmol) Trifluoro-methanesulfonic acid 3-(4-trifluoromethyl-phenyl)-benzo[d]isothiazol-6-yl ester in 20 ml piperidine 447.0 mg (3.9 mmol) tetrakis(triphenylphosphine)palladium and 73.6 mg (3.9 mmol) CuI were added. At 80° C. 1.43 ml (15.45 mmol) 4-pentyn-1-ol were added slowly, and the solution was stirred for an additional hour. The cooled solution was added to ice water, acidified with 2M HCl and extracted with ether. The combined organic phases were washed with water and dried over Na2SO4. Column chromatography on silica gel with CH2Cl2:MeOH 30:1 yielded 2.7 g (96%) 5-[3-(4-Trifluoromethyl-phenyl)-benzo[d]isothiazol-6-yl]-pent-4-yn-1-ol as orange oil, MS: 361 (M).

Provenance & Evidence