The one-step cyclocondensation of substituted isoflavones with cyanothioacetamide in the presence of sodium hydroxide gave an array of 3-cyano-5,6-diaryl pyridine-2(1H)-thiones in good yields. The procedure involves base-mediated ring opening of the isoflavones and subsequent Knoevenagel condensation between the 1,3-dicarbonyl intermediate generated from the isoflavones and cyanothioacetamide, followed by ring closure and dehydration.
Organic & Biomolecular Chemistry
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