VERFAHREN ZUR HERSTELLUNG VON 1-PYRAZOLINEN.

摘要

Prodn. of 1-pyrazolines of formula (I) is effected by (a) stirring a 10-30% aq. soln. of a 1,3-diaminopropane of formula (II) while simultaneously adding a 5-22 wt.% aq. hypochlorite soln. and a 20-50 wt.% aq. soln. of a hydro-peroxide of formula (III) in a hypochlorite: (III) molar ratio of 1:0.5-1.5, the temp. not being allowed to exceed 60 deg. C; (b) rapidly extracting (I) with a hydrophobic organic solvent at room temp.; and (c) distilling the extract in vacuo at a temp. below 100 deg.C: R1-R6 = H or 1-3C alkyl, or 2 such gps. on the same or adjacent C atoms linked to form 3-5C alkylene; R = H, 1-5C alkyl or 2-5C aliphatic acyl. Pref. a 15-19% hypochlorite soln. and a 40-50% H2O2 soln. are added at a rate such that the ClO- and H2O2 concn. never exceeds 5%.