| 摘要 |
1,227,375. 2 - Methyl - 3 - cyano - quinoxaline di-N-oxides. FARBENFABRIKEN BAYER A.G. 9 July, 1968 [8 Aug., 1967], No. 32749/68. Addition to 1,187,991. Heading C2C. The invention comprises quinoxaline di-N- oxides of the formula wherein R represents hydrogen, halogen or an alkyl, alkoxy, carbalkoxy, carboxylic amide or sulphonamido group, in which the amide groups may be mono- or di-alkyl-substituted, and the preparation thereof by heating to 40-80‹ C., in a water-miscible organic solvent, 5-methyl-isoxazole, or an isomeric mixture of 4- and 5-methylisoxazoles, with at least an equimolar amount, based on 5-methylisoxazole, of an alkali metal hydroxide or alcoholate and reacting the resulting solution, if desired after cooling to 15-25‹ C., with an equimolar amount, based on 5-methyl-isoxazole, of a benzofuroxane of the formula in a water-miscible organic diluent in the presence of at least equimolar amounts, based on benzofuroxane, of ammonium chloride and ammonia at 20-80‹ C. Specified solvents and diluents include alcohols, cyclic ethers, dimethylformamide and acetamide and dimethylsulphoxide. Examples relate to the preparation of compounds in which R is hydrogen, chlorine, a methyl and a methoxy group. |
