Table 1.

Synthesis of highly substituted spiro indolin-1,2-diazepine derivatives 5a-v^a,b

^aReaction conditions: N-aryl-1-(methylthio)-2-nitroethenamine (1 mmol), NH₂NH₂ (80% aq) (1.2 mmol) were added to ethanol (5 mL) at room temperature and after 3-4 h, isatin derivatives (1 mmol) and malononitrile (1 mmol) were added to obtain the desired product 5.

^bIsolated yield.