Chlorosulfonic acid → 1-(Trifluoroacetyl)-2,3-dihydro-1H-indole-5-sulfonyl chloride

Participants

Reaction Steps

2,2,2-trifluoro-1-(indolin-1-yl)ethanone (5 g, 16 mmol) was added to neat chlorosulfonic acid at 0° C. and then the solution was allowed to warm to rt and stirred for an additional 2 hrs. Reaction mixture was slowly added to ice chips and stirred for 10 min then filtered off 4.2 g of the title compound as a dark red colored solid.

Provenance & Evidence