Cross-condensation of derivatives of cyanoacetic acid and carbonyl compounds.: Part 1:: Single-stage synthesis of 1′-substituted 6-amino-spiro-4-(piperidine-4′)-2H,4H-pyrano[2,3-c]pyrazole-5-carbonitriles

To develop a method of synthesis of the potentially physiologically active compounds, 1'-substituted 6-amino-spiro-4-(piperidine-4')-2H,4H-pyrano[2,3-c]pyrazoles, we studied the three-component condensation of substituted piperidin-4-ones, malononitrile and pyrazolin-5-ones. It was found that the electrochemical method of synthesis is more regioselective, the products of the reaction are analytically pure and do not require further recrystallization. (C) 2003 Elsevier Ltd. All rights reserved.