Solvent Effect on Product Distribution in the Thermolysis of Dihydropyrazoles ... Masashi Hamagwhi* and Toshikazu Nagai Institute of Chemistry, College of General Education, Osaka University, To yonaka, Osaka 560, Japan ... Solvent dependence of products in the thermal decomposition of 4-methoxy-4,5-dihydro-3H-pyrazoles bearing two electronegative groups at C-3 was observed; nonpolar solvents gave predominantly alkenes, whereas polar solvents gave ...