Ammonia → HCID 13671488, compound

Participants

Reaction Steps

A solution of 3.9 g. (0.038 mol) potassium nitrate in 30 ml. concentrated sulphuric acid is added dropwise, while cooling, to a solution of 13 g. (0.038 mol) 3-ethoxycarbonyl-3-methyl-6-(4-pyridinoylamino)-indolin-2-one in 90 ml. concentrated sulphuric acid. The reaction mixture is further stirred for about 1 hour, poured on to ice, adjusted to pH 8 with a concentrated aqueous solution of ammonia, while cooling, and the crystals obtained are filtered off with suction and recrystallised from ethanol/methylen chloride. Yield: 12.81 g. (82% of theory); m.p. 217°-219° C.

Provenance & Evidence