Oxadiazoline derivatives of the formula: ##STR1## WHEREIN R is alkyl of 1 through 4 carbon atoms, which are useful as intermediates in the synthesis of oxadiazoline derivatives of the formula: ##STR2## WHEREIN R is as defined above the R.sub.1 is alkyl of 1 through 4 carbon atoms, possessing useful herbicidal properties, are prepared by a new process which comprises reducing the nitro group in a 5-alkyl-3-(2-nitro-4-chlorophenyl)-1,3,4-oxadiazolin-2-one of the formula: ##STR3## wherein R is as defined above to a hydroxylamino group, treating the resulting 5-alkyl-3-(2-hydroxylamino-4-chlorophenyl)-1,3,4-oxadiazolin-2-one with concentrated sulphuric acid of density about 1.83 to produce the corresponding amino-phenol, and converting the amine group in the resulting 5-alkyl-3-(2-amino-4-chloro-5-hydroxyphenyl)-1,3,4-oxadiazolin-2 -one to a chlorine atom. The 5-alkyl-3-(2-hydroxylamino-4-chlorophenyl)-1,3,4-oxadiazolin-2-one intermediates are new compounds.
本发明涉及一种新的制备方法,其中R为1至4个碳原子的烷基,其为合成具有有用除草特性的公式为:##STR2##其中R如上所述的氧代二唑衍
生物的中间体。该中间体的制备方法包括将公式为:##STR3##其中R如上所述的5-烷基-3-(2-硝基-4-
氯苯基)-1,3,4-氧代二唑-2-酮的硝基还原为
羟胺基,用密度约为1.83的浓
硫酸处理所得的5-烷基-3-(2-
羟胺基-4-
氯苯基)-1,3,4-氧代二唑-2-酮,以产生相应的
氨基
酚,并将所得的5-烷基-3-(2-
氨基-4-
氯-5-羟基苯基)-1,3,4-氧代二唑-2-酮中的
氨基转化为
氯原子。其中5-烷基-3-(2-
羟胺基-4-
氯苯基)-1,3,4-氧代二唑-2-酮中间体为新化合物。