Indole → 3-Chloroacetylindole

Participants

Reaction Conditions

Reaction Steps

To a stirred solution of 6.00 g (51.2 mmole) indole and 4.2 ml (47.5 mmole) pyridine in 50 ml toluene at 55° C. was added dropwise 5.85 g (51.8 mmole) chloroacetyl chloride. The resulting orange-colored mixture was stirred at 55° C. for 90 minutes and cooled to room temperature. Water (150 ml) and methanol (25 ml) were added and the mixture stirred for another hour. The precipitate was collected, washed with water (50 ml) and dried to give 10.18 g of crude product. This was triturated with chloroform, filtered, the solid washed with chloroform and crystallized from methanol to afford 2.35 g (23%) of product; m.p. 236°-237° C. Reworking the mother liquors gave a second crop which was purified by flash chromatography on silica gel. Two recrystallizations of this product gave an analytically pure product; m.p. 236°-237° C.

Provenance & Evidence