Synthetic Reactions of Coumarin-3-(4-Aminosulfonyl)-Carbanilide Derivatives With Reactive Methylene Compounds

Coumarin and benzo[f]coumarin–3–(4–aminosulfonyl)carbanilide derivatives 3a, b react with malononitrile or ethyl cyanoacetate to afford pyrido[3,4–c]– and pyrido[3,4–c]–benzo–[f]coumarin derivatives 4a–d. Compounds 4a–d were also prepared by treatment of arylidene–malononitrile or arylidenecyanoester derivatives 1a–d with ethyl 2–[4–aminosulfonyl carbanilide]acetate 2. 3a, b Derivatives were also allowed to react with a variety of active methylenes having an α–cyano or α–keto group to give pyrido[3,4–c]– and pyrido[3,4–c]–benzo[flcoumarin derivatives 5a, b–11a, b through a nucleophilic addition and cyclization.