Self-Catalyzed One-Pot Four-Component Green Synthesis of 2-Amino-6-[1,4-dioxo-3,4-dihydrophthalazin-2(1H)-yl]-4-phenyl-4H-pyran-3,5-dicarbonitriles

Abstract

The title compounds were synthesized in good yields by one-pot four-component condensation of phthaloyl dichloride, ethyl cyanoacetohydrazide, malononitrile, and substituted benzaldehydes in boiling ethanol for 1–2 h. The reaction involves in situ generation of hydrogen chloride in the first step, which catalyzes further addition, dehydration, and cyclization steps. The procedure is advantageous due to easy workup, short reaction times, good yields, the use of ethanol as a green solvent, and no external catalyst is needed.