Umlagerung von Ketazinen in Pyrazoline

Hydrazine in Organic Chemistry

“…Dihydropyrazole derivatives are formed by treating ,ß-ethylenic ketones or aldehydes such as mesityl oxide or acrolein with hydrazine (219,368). They may also be made from azines of the fatty acid series having at least one methyl group next to the azine; ring closure is brought about by organic or mineral acids (83,89,144,155).…”