Formic Acid → 5,7-dihydro-7,7-dimethylpyrrolo(2,3-f)benzimidazol-6(1H)-one

Participants

Reaction Steps

288 mg. (1.51 mmole) 5,6-diamino-3,3-dimethylindolin-2-one and 66 mg. (1.43 mmole) formic acid are heated for 1 hour at 100° C. After the addition of a further 24 mg. (0.52 mmole) formic acid, the reaction mixture is further heated to 100° C. for 60 minutes. Thereafter, trituration is carried out with 0.5 ml. amounts of diethyl ether, followed by suction filtration. There are obtained 277 mg. (91% of theory) of the title compound in the form of pale crystals; m.p. 278°-280° C.

Provenance & Evidence