Synthesis of 9,11-diamino-12 H-benzo[5,6]-chromeno[2,3- b]pyridine-10-carbonitriles.

The article focuses on the synthesis of 9,11-diamino-12 H-benzo[5,6]-chromeno[2,3- b]pyridine-10-carbonitriles. The pseudo-three-component reaction apparently proceeds via generation of the o-quinone methide A from the Mannich base, followed by addition of malononitrile by a Michael reaction, intramolecular heterocyclization and condensation of enaminonitrile B formed with a second equivalent of malononitrile, which leads to construction of the pyridine ring.