A simple, efficient, and eco‐friendly procedure has been developed for the synthesis of bis(4H‐chromene‐3‐carbonitrile) derivatives using chitosan as catalyst under microwave‐assisted reaction conditions. For the sake of comparison, the reaction was also carried out under conventional heating in the presence of each of chitosan and piperidine as basic catalysts.

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A synthesis of novel bis(4‐(14H‐dibenzo[a,j]xanthenes) and bis(dihydro‐8H‐benzo[a]xanthenones) was performed in good yields via pseudo‐multicomponent, or multicomponent reactions, of bis‐aldehydes with four equivalents of β‐naphthol or with a mixture of two equivalents of each β‐naphthol and dimedone in the presence of a catalytic amount of p‐toluenesulfonic acid. Bis(pyrano[3,2‐c:5,6‐c′]dichromenediones) or tetrakis(4‐hydroxy‐2H‐chromen‐2‐ones) could also be obtained in good yields through pseudo‐multicomponent reactions of bis(aldehydes) with four molar ratio of 4‐hydroxycoumarin.

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