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.