Isatin → 5H-[1,2,4]Triazino[5,6-b]indole-3-thiol

Participants

Reaction Steps

A mixture of 7.36 g (50.0 mmoles) of isatin, 250 ml of water, 5.01 g (55.0 mmoles) of thiosemicarbazide and 10.4 g (75.0 mmoles) of potassium carbonate was heated to reflux. After 30 minutes, a red solution resulted which was cooled to room temperature and filtered through celite. The pH was adjusted to 4.5 with glacial acetic acid and the resulting yellow solid was collected and washed with hot ethanol. After drying, 8.04 g of material was obtained. (J. Medicinal Chemistry, 15:277 (1972))

Provenance & Evidence