Methyl 6-chloropyridazine-3-carboxylate (1) is a key intermediate in the research of anti-tumor, blood-lipid lowering and insecticides. In this article, methyl 6-chloropyridazine-3-carboxylate (1) is synthesized by using ethyl levulinate as starting material via a six-steps process including cyclization, bromination, elimination, oxidation, esterification and chlorination in the overall yield of 42%. This method is easy to operate and purificate with good yield, and the starting material is cheap. It has established a way to prepare methyl 6-chloropyridazine-3-carboxylate (1) on a large scale.

Key words: methyl 6-chloropyridazine-3-carboxylate, ethyl levulinate, synthesis