Construction of 3,4‐dihydro‐1,2‐diazete ring through 4π electron cyclization of 4‐hydroxy‐2‐oxo‐2H chromene‐3‐carbaldehyde [(1E)‐arylmethylene] hydrazone

Abstract

A new, short and efficient synthesis of 4‐hydroxy‐3‐(4‐aryl‐3,4‐dihydro‐1,2‐diazet‐3‐yl)‐2H‐chromen‐2‐one is described in which the 3,4‐dihydro‐1,2‐diazete ring is constructed from arylmethylene hydrazone by 4π electron cyclization as per electrocyclic reaction. J. Heterocyclic Chem., (2010).

An efficient synthesis of novel isoxazole bearing pyrazole derivatives via [3 + 2] heteroannulation using cupric acetate

“…Our previous work to synthesize novel heterocycles [ 37–39 ] using catalyst and the tremendous biological importance of isoxazole derivatives motivated us to synthesize novel pyrazole bearing isoxazole heterocycles. As discussed earlier, cycloaddition reaction without catalyst results in the formation of byproduct and gives lower yields of product.…”