| 摘要 |
Pyrazole and its derivs. (I) are produced by dehydrogenation of the corresp. 2-pyrazoline (II) with the aid of sulphuric acid in the presence of iodine or an iodine cpd. (III) at 50-250 deg.C. (II) is produced in situ in the reaction medium by reaction of glycerol or acrolein or a deriv. thereof with hydrazine or a hydrazine deriv.; amt. of (III) is 0.01-10 mol. equiv. w.r.t. (II) or the corresp. hydrazine; 30-99 wt.% H2SO4 is used. |
