4-Methyl-5-oxo-3-thioxo-tetrahydro-1,2,4-(2H,4H)-triazines, which are intermediate products for known herbicides, can be prepared in high yields by a process in which an acyl cyanide of the general formula R--CO--CN (II) wherein R represents an optionally substituted aliphatic radical having up to 12 carbon atoms, an optionally substituted cycloalkyl radical having 3 to 10 carbon atoms, an optionally substituted phenyl or naphthyl radical or an optionally substituted heterocyclic radical, is reacted with a carboxylic acid anhydride of the general formula R.sup.1 --CO--O--CO--R.sup.1 (II) in which R.sup.1 represents an optionally substituted aliphatic radical having up to 8 carbon atoms or an optionally substituted phenyl radical, in the presence of a strong acid and, if appropriate, in the presence of a solvent, at a temperature between -50.degree. and 150.degree. C., and the reaction mixture thus obtained is then reacted directly with 4-methyl-thiosemicarbazide (CH.sub.3 --NH--CS--NH--NH.sub.2).
4-甲基-5-氧代-3-硫代-四氢-1,2,4-(2H,4H)-三嗪是已知除草剂的中间产物,可以通过一种方法高产率制备。该方法中,通式为R--CO--CN (II) 的酰基氰化物与通式为R.sup.1 --CO--O--CO--R.sup.1 (II) 的羧酸酐反应,其中R表示具有最多12个碳原子的可选取代的脂肪基,具有3到10个碳原子的可选取代的环烷基,可选取代的苯基或萘基或可选取代的杂环基,R.sup.1表示具有最多8个碳原子的可选取代的脂肪基或可选取代的苯基,在强酸存在下,如有必要,在溶剂存在下,在-50℃至150℃的温度下反应,然后将得到的反应混合物直接与4-甲基硫脲(CH.sub.3--NH--CS--NH--NH.sub.2)反应。
3-Dimethylamino-4-methyl-1,2,4-triazin-5(4H)-ones and herbicidal
申请人:Bayer Aktiengesellschaft
公开号:US04447258A1
公开(公告)日:1984-05-08
3-Dimethylamino-4-methyl-1,2,4-triazin-5(4H)-one compounds of the formula ##STR1## in which R.sup.1 is t-butyl, sec.-butyl or cyclohexyl; are effective herbicides.