With the rapid development and complex challenges of chemical substances, new drug synthesis pathways are usually the most effective.1352925-63-3,Ethyl 4,6-dihydroxypyridazine-3-carboxylate,as a common compound, the synthetic route is as follows.
Step 3.Preparation of 4,6-dichloro-pyridazine-3-carboxylic acid methyl or ethyl ester 5 A mixture of 4,6-dihydroxy-pyridazine-3-carboxylic acid methyl or ethyl ester (50 mmol) and POCl3 (90 ML) is heated at 95 C. for 4 hours.The excess POCl3 is evaporated in vacuo and to the residue cooled to 0 C. was added ice (150 g) followed by EtOAc (200 ML).The layers are separated and the aqueous layer is extracted with EtOAc (2*100 ML).The combined extracts are washed with brine (200 ML), dried (Na2SO4) and evaporated in vacuo.This residue is purified by flash column chromatography (225 g silica gel, eluted with 4:1 hexane, EtOAc).The desired 4,6 dichloro-pyridazine-3-carboxylic acid methyl ester is obtained as a white solid, while the 4,6 dichloro-pyridazine-3-carboxylic acid ethyl ester is a colorless liquid., 1352925-63-3
The synthetic route of 1352925-63-3 has been constantly updated, and we look forward to future research findings.
Reference：
Patent; Xie, Linghong; Han, Bingsong; Xu, Yuelian; Maynard, George D.; US2004/77653; (2004); A1;,
Pyridazine – Wikipedia
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