Conversions of 2-(2-Oxo Cyclohexylcarbonyl)Benzoic Acid Derivatives to Pyrazolo[, , , , , , , , , , ]Isoindole and Pyrimidine Rings

Synthesis of Pyrazolo[5,1-a]isoindoles and Pyrazolo[5,1-a]isoindole-3-carboxamides through One-Pot Cascade Reactions of 1-(2-Bromophenyl)buta-2,3-dien-1-ones with Isocyanide and Hydrazine or Acetohydrazide

“…Fused pyrazoles have stimulated considerable attention, as they are key structural motifs in compounds with important biological activities. , In particular, pyrazolo­[5,1- a ]­isoindoles are endowed with plant growth regulating, antihypertensive, antiamoebic, and antidepressant activities . Because of their importance, a number of approaches have been developed for the synthesis of pyrazolo­[5,1- a ]­isoindoles, including reaction of iminophosphoranes with acetylenic compounds, intramolecular Wittig reaction of phosphorus ylides, condensation of phthalaldehydic acid with acetophenones followed by condensation with hydrazine hydrate, Suzuki cross-coupling reaction of pyrazolylboronic esters, intramolecular C–H bond activation of 1-(2-halobenzyl)­pyrazoles, photochemical intramolecular [3 + 2] cycloaddition of stilbene-methylene-sydnones, and intramolecular Friedel–Crafts acylation of chalcone-based N -formylpyrazolines .…”

“…1,2 In particular, pyrazolo [5,1-a]isoindoles are endowed with plant growth regulating, 3 antihypertensive, 4 antiamoebic, 5 and antidepressant activities. 6 Because of their importance, a number of approaches have been developed for the synthesis of pyrazolo [5,1-a]isoindoles, including reaction of iminophosphoranes with acetylenic compounds, 7 intramolecular Wittig reaction of phosphorus ylides, 8 condensation of phthalaldehydic acid with acetophenones followed by condensation with hydrazine hydrate, 9 Suzuki cross-coupling reaction of pyrazolylboronic esters, 10 intramolecular C−H bond activation of 1-(2-halobenzyl)pyrazoles, 11 photochemical intramolecular [3 + 2] cycloaddition of stilbene-methylenesydnones, 12 and intramolecular Friedel−Crafts acylation of chalcone-based N-formylpyrazolines. 13 While these literature procedures are generally efficient and reliable, some of them still suffer from difficult-to-obtain substrates, tedious operation procedures, and harsh reaction conditions.…”