Benzene → Indol-6-one

Participants

Reaction Steps

A mixture of 5 g of 3,4-dihydro-1H-cyclohept[c,d] indol-6-one, 50 ml of benzene, 2.5 ml of methyl iodide, 25 ml of 5 N sodium hydroxide solution and 9.2 g of tetra-n-butyl ammonium acid sulfate was stirred for 30 minutes under an inert atmosphere at 40°-45° C. and the mixture was diluted with water. The decanted aqueous phase was extracted with ethyl acetate and the organic phase was washed with N hydrochloride acid, with water, dried and evaporated to dryness. The residue was chromatographed over silica gel and was eluted with a 95-5 chloroform-ethyl acetate mixture to obtain 6.5 g of raw product. The latter was crystallized from isopropanol to obtain 5.15 g of 1-methyl-1,3,4,5-tetrahydro-6H-cyclohept [c,d,] indol-6-one melting at ≃70° C.

Provenance & Evidence