Study On Synthesis Of Substituted Hydroxypirimidine

New pesticides with efficient, low-toxicity and novel structure were emerging and expanding market share during the past three decades. However, several varieties of pesticides which core intermediate is N-alkylamino-5,6-alkyl-4-hydroxypyrimidine (referred to as the hydroxypyrimidine) did not decline in the global market share, had stable market demand and generous profits, because of their low toxicity, stability control effect of the specific target, no resistance, and security for beneficial organisms. The market of the pesticides is major in foreign countries. The quality requirement of the products is high, and the content of harmful impurities need strict control. So the production of dihydroxypyrimidine is the key, which has direct impact on the quality of the pesticides, the cost of intermediate has impact on the cost and profit of the pesticides. The market share of the pesticides was affected by some problems in the process route of dihydroxypyrimidine at present, such as heavy pollution, odor, poor product quality.In response to these problems, and learn from our key technologies of development2,2-diethylamino-6-methyl-4-hydroxypyrimidine, by appropriately changing the synthesis conditions, application to synthesis process of other hydroxypyrimidine compounds, thereby increasing the yield, improve product quality, reduce production costs and reduce environmental pollution. Mainly to carry out the following work:1, As lower price, higher atomic utilization of methyl acetoacetate instead of ethyl acetoacetate, catalytic hydrogenation reaction with formaldehyde to synthesis of methyl2-methyl acetoacetate, the reaction is mild, and yield of85.5%, the purity of the product is more than95%. Compared with the existing methods of synthesis ethyl2-methylacetoacetate with dimethyl sulfate and ethyl acetoacetate, our work increased the yield and content of ethyl2-methylacetoacetate, ensured the content of corresponding of hydroxypyrimidine and the original drug, controled a large part of harmful impurities in source, with lower production costs and less waste.2, Prepared1,1-dimethylguanidine and1,1-diethylguanidine as sulfuric acid, dimethylamine (or ethyl amine) reaction with cyanamide, successfully applied multiple batches of mother liquor, significant increased the yield and content of the production. Compared with the conventional method, wastewater reduced by90%and85%or more, respectively.3, Using a patented technology, synthesized2-ethylamino-5-n-butyl-6-methyl-4-hydroxypyrimidine as raw material of1,1-diethylguanidine and2-butyl acetylacetate. The reaction conditions were optimized as reaction yield was96.4%and content of98.2%, significantly increased the yield and content compared with the the domestic existing production process, in particular avoided to produce methyl mercaptan and heavy pollution problems of the old process.4, Using a patented technology, synthesised2,2-dimethylamino-5,6-dimethyl-4-hydroxypyrimidine (Pirimicarb intermediate) as methyl2-methylacetoacetate cyclization with sulfuric dimethoxy guanidine, yield of96.4%, more than the literature value with three percentage points. The content of direct synthesis products get98%or more, with its synthetic Pirimicarb completely meet the export requirements.5, The technology of synthesis2,2-dimethylamino-5,6-dimethyl-4-hydroxypyrimidine has been successfully applied on a500tons/year production plant, the yield and content reach the level of small trial, and exported volume with its production of pirimicarb. The production unit of2,2-dimethylamino-5-butyl-6-methyl-4-hydroxy-pyrimidine is designing, the achievement of research has application value.