PROCEDEU DE PREPARARE A FENILPIRIDAZINELOR

摘要

1362886 Phenylpyridazines CHEMIE-LINZ AG 2 June 1972 [11 June 1971] 25968/72 Heading C2C The invention comprises phenylpyridazines of general Formula (I) in which X is a chlorine or bromine atom and R is H, CH 3 or CH 3 CO, and their preparation by reacting a phenyldihalopyridazine of general formula in which Y is Cl or Br, with a compound MO R 1 , where M is an alkali metal or the equivalent of an alkaline earth metal and R 1 is H or CH 3 , preferably in an aqueous medium or in an organic solvent, e.g. methanol at 50‹ to 100‹ C., after which, when R in Formula (I) is CH 3 CO, the latter is introduced by acetylation of the hydroxy group. Examples describe the preparation of 3-phenyl-4-hydroxy-6-chloropyridazine,' 3 - phenyl - 4 - methoxy - 6 - chloropyridazine, 3 - phenyl - 4 - hydroxy - bromopyridazine and 3 - phenyl - 4 - acetoxy - 6- chloropyridazine. 3 - Phenyl - 4,6 - dichloropyridazine and 3- phenyl-4,6-dibromopyridazine are prepared by reacting 3 - phenyl - 4 - chloropyridazone - 6 with POCl 3 and PBr 5 respectively. Herbicidal compositions for the selective combating of weeds in crop plantings comprise one or more phenylpyridazines of general Formula (I) in admixture with a carrier, e.g. kaolin, preferably in the form of a dispersion, an emulsion, a pulverulent preparation or in the form of granules and when in the form of an aqueous dispersion or emulsion admixed with a wetting agent such as sodium oleyl-methyltauride.