The preparation of selected benzopyrano[3,4‐b]pyrazoles by the condensation of c(α), n‐dilithiocarboalkoxyhydrazones and salicylate esters

Selected C(α),N-dilithiocarboalkoxyhydrazones were prepared in an excess of lithium diisopropylamide (LDA) and condensed with a variety of salicylate esters to give intermediates that were acid-cyclized to benzopyrano[3,4-b]pyrazoles (coumarin-pyrazoles).

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