I just want to synthesize simple pyrazolines with no N-acetylation. Is the acetic acid method reliable to do so, or is there a preferable method to get pyrazolines other than using methanol as solvent?
--- A mixture of Chalcones (0.01 mole) in 25 ml of absolute alcohol, add hydrazine hydrate (0.015 mole) is heated under reflux in water bath at temp. 80-90 ºC [~8 h]. The reaction is monitored by TLC.
***If no reaction is observed then add 1ml glacial acetic acid and 1ml PEG (400) and continue heating on hot-plate [ follow up your reaction with TLC].
Good luck
See
Lavania, Asha; Dasary, Kiran; Yadav, Manju; Anand, Anita V. K., Journal of Applicable Chemistry (Lumami, India) (2013), 2(5), 1341-1346
I did several tests to synthesize pyrazolines from an a, b unsaturated aldehyde but I can not obtain pyrazoline as reported in the literature. I have tested in EtOH at room temperature, with KOH, with heating and in no way obtained them. I always get to hydrazone but with low yields. What I can do?