Hydrochloric Acid → Indol-2-one

Participants

Reaction Conditions

Reaction Steps

604 mg of 3-(3-amino-4-methoxyphenyl)-1-trifluoroacetyl piperidine were added with stirring under an inert atmosphere to 20 ml of methylene chloride and 0.26 ml of ethyl methylthioacetate cooled to -65° C., and then 0.24 ml of tert-butyl hypochlorite were added over 5 minutes. After stirring for an hour, 0.29 ml of triethylamine were added dropwise and the temperature was allowed to return to ambient. 5 ml of aqueous 2N hydrochloric acid were added and the mixture was stirred for an hour. The decanted organic phases were washed with water, dried and filtered. The filtrate was evaporated to dryness under reduced pressure and the residue was chromatographed over silica (eluent benzene--ethyl acetate 7-3) to obtain 580 mg of 1,3-dihydro-7-methoxy-3-methylthio-4-[1-trifluoroacetyl)-3-piperidinyl]-2H-indol-2-one which after crystallization from ethanol melted at ≈189° C.

Provenance & Evidence