Reference of 1193-24-4 , The common heterocyclic compound, 1193-24-4, name is 4,6-Dihydroxypyrimidine, molecular formula is C4H4N2O2, its traditional synthetic route has been very mature, but the traditional synthetic route has various shortcomings, such as complicated route, low yield, poor purity, etc., below Introduce a new synthetic route.
A kind of the improved 4, 6 – dichloro pyrimidine production process, characterized in that the production process comprises the following steps: (1) to the reaction kettle top feed port input 1 parts by weight of 4, 6 – dihydroxy pyrimidine and 3 parts by weight of chloroform, opening the stirrer stirring, continue adding 0.5 parts by weight of pyridine catalyst, and then open the jacket steam make the reaction kettle temperature to rise to 50 C, from the reactor into the bottom of the 1 parts by weight of phosgene to the phosgenation reaction, after the reaction is complete, to inject the nitrogen in the reactor catches up with was mad, at the same time the exhaust gas by the pipe into the absorption tower; (2) to be step 1 the product in the transfer to the rectifying tower, control rectification temperature is 65 C, collecting chloroform fraction, to be its after cooling to room temperature, the filling storage recycling; (3) collecting the step 2 in the remaining product, transferred to ice in the ice solution, slowly dropping concentration is 10% hydrochloric acid to adjust the pH of the solution to 5, standing the solution is layered, then methyl tert-butyl ether to the organic phase extraction, extraction 3 – 4 times, saturated copper sulfate solution for washing, until the copper sulfate solution is not color-changing, collecting pyridine circulation use; (4) the step 3 in the remaining product to filter, washing, and drying to obtain the target product 4, 6 – dichloro pyrimidine.The beneficial effects of the present invention: 1) using phosgene to replace the traditional process of phosphorus oxychloride, to avoid the emergence of phosphorus-containing by-product, the protection of the environment; 2) by adding pyridine catalyst, can accelerate the reaction of generating; 3) traditional use phosphorus oxychloride with 4, 6 – dihydroxy pyrimidine chloride obtained when the 4, 6 – two chlorine pyrimidine, easy to produce 3 different by-product, so that the trouble in processing after, and the yield of target product is not high, in the reaction of the present invention less by-products, and the yield of 4, 6 – dichloro pyrimidine higher; 4) by adjusting the solution pH, methyl tert-butyl ether extraction, and sulfuric acid copper and washing the collecting various pyridine, avoiding the traditional rectification, and steaming and method and the like caused by the leakage of pyridine, ensures the safety of the operators.
The synthetic route of 1193-24-4 has been constantly updated, and we look forward to future research findings.
Reference:
Patent; Anhui Guangxin Agrochemical Co., Ltd; Huang, Jinxiang; Guo, Xuejun; wu, Jianping; hu, minghong; tang, Xiude; cheng, Weijia; li, Hongwei; Xu, Xiaobing; Yang, Zhiwei; Gao, yanbing; (4 pag.)CN106187913; (2016); A;,
Pyrimidine | C4H4N2 – PubChem,
Pyrimidine – Wikipedia