Plant-protective 2 -acylamino-1,3,4-oxadiaz- - oles

摘要

(a) 2-Acylamino-1,3,4-oxadiazoles (III) are produced by reacting iminocarbonic ester derivs. (I) with acylhydrazines (II) pref. at -20 to +80 degrees in presence of a solvent. They are plant-protective agents. R = haloalkyl or an opt. substd. arom. residue opt.: joined to a heterocycle. R' = opt. substd. aliphatic arom. or heterocyclic residue X = halogen n = 0 or 1. R2 = H or an opt. substd. aliph. arom. or heterocyclic residue. (b) Compounds (II) where n = 1 are specifically claimed. In an example 9.6 g (89%) 2-propionyl-5-phenyl-oxadiazole, m.p. 218 degrees are obtained from 13.3 g (0.05 mol) Cl3C-CH2 OC=N-COCH2CH3 and 13.6 g (0.1 mol) benzhydrazide in dioxan at 10 degrees.