Hydrochloric Acid → Indol-2-one

Temperature

-65 °C

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.

1. stirringthe mixture was stirred for an hour
2. washThe decanted organic phases were washed with water
3. customdried
4. filtrationfiltered
5. customThe filtrate was evaporated to dryness under reduced pressure
6. customthe residue was chromatographed over silica (eluent benzene--ethyl acetate 7-3)

ORD record

ord-b5e44192c0064fa9a8d5a7f3ff3b3a1c

Source dataset

uspto-grants-1988_04

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04736034