Thermal isomerization pathway of 1-(4-nitrophenyl)-2-phenylimino-2,5-dihydro-1H-pyrido[3,2-b]indole-3-carbonitrile discovered by laboratory powder data.

The evidence for thermal isomerization of the title compound, C(24)H(15)N(5)O(2), into 2-[(4-nitrophenyl)phenylamino]-5H-pyrido[3,2-b]indole-3-carbonitrile has been obtained as a consequence of crystal structure determinations from laboratory powder data.