METHOD FOR PREPARING 4,6-DIMETHOXY-2-METHYLSULFONYLPYRIMIDINE (VARIANTS) AND ITS USING Russian patent published in 2006 - IPC C07D239/60 C07D405/12 A01N43/54 A01P13/00 

FIELD: organic chemistry, chemical technology.

SUBSTANCE: invention relates to the improved method for preparing 4,6-dimethoxy-2-(methylsulfonyl)-1,3-pyrimidine. Method involves reaction of 4,6-dichloro-2-(methylthio)-1,3-pyrimidine with alkaline metal methoxide in inert organic solvent, transfer of prepared 4,6-dimethoxy-2-(methylthio)-1,3-pyrimidine in aqueous acid medium and the following oxidation of this compound in the presence of catalyst if necessary, preferably, with an interphase catalyst, such as tricaprylmethylammonium chloride. Then method involves carrying out the purification stage wherein pH value of the aqueous acid reaction mixture is brought about to the value from 5 to 8 with aqueous base, such as alkaline metal hydroxide, for example, sodium hydroxide at temperature 10-90°C and stirring in the presence of absence of organic solvent, for example, aromatic hydrocarbon, such as benzene, toluene or isomeric xylenes, or alcohol, such as methanol or ethanol. Also, invention relates to using the prepared compound as an intermediate substance for synthesis of herbicide, in particular, 7-[(4,6-dimethoxypyrimidin-2-yl)thio]-3-methylphthalide by reaction of 7-mercapto-3-methylphthalide of compound in preparing herbicides, for example, 7-[(4,6-dimethoxypyrimidin-2-yl)thio]-3-methylphthalide.

EFFECT: improved preparing method.

24 cl, 2 sch, 1 ex