Chlorosulfonic acid → 4-(1-(2,2,2-Trifluoroacetyl)piperidin-4-yl)benzene-1-sulfonyl chloride

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Reaction Steps

Chlorosulfonic acid (2 mL) was added to 2,2,2-trifluoro-1-(4-phenylpiperidin-1-yl)ethanone (1.0 g, 3.9 mmol) in a single portion, and the reaction was stirred for 20 minutes until gas evolution ceased (exothermic reaction). The solution was poured into a mixture of ice water (200 mL) and EtOAc (20 mL). The organic layer was concentrated and purified via silica gel chromatography using 8/2 hexanes/EtOAc to obtain 4-(1-(2,2,2-trifluoroacetyl)piperidin-4-yl)benzene-1-sulfonyl chloride as a clear oil (1.3 g, 94%). 1H NMR (400 MHz, CDCl3) δ 8.02-8.00 (m, 2H), 7.48-7.45 (m, 2H), 4.78-4.73 (m, 1H), 4.19 (dd, J=14.0, 1.6 Hz, 1H), 3.32-3.25 (m, 1H), 3.02-2.86 (m, 2H), 2.03-2.02 (m, 2H), 1.81-1.70 (m, 2H).

Provenance & Evidence