Arylidene malononitrile reacted with cyanothioacetamide under basic condition to afford
the pyridine derivative (2). The same product was obtained from the reaction o f arylidene
ethylcyanoacetate, arylidene diethyl malonate, arylidene pyrazolinone with cyanothioacetam ide
under the same condition. A resonable mechanism for this behaviour was suggested.