Regio- and stereoselective route to bis-[3-methyl-1,1′,4′-triaryl-5-oxo-spiro-pyrazoline-4,5′-pyrazoline] derivatives via 1,3-dipolar cycloaddition under sonication

Bis-[3-methyl-1,1',4'-triaryl-5-oxo-spiro-pyrazoline-4,5'-pyrazoline] derivatives are synthesized regio- and stereoselectively via 1,3-dipolar cycloaddition of the bis-hydrazonoyl chlorides with 4-arylidenepyrazol-5-one derivatives. The cycloaddition route is optimized under both ultrasonic irradiation and conventional heating modes. The regio- and stereoselectivity of the cycloadducts are confirmed by spectral and X-ray crystallographic analysis. (C) 2017 The Authors.