ethyl 6-ethyl-6,7-dihydro-3-methyl-7-oxo-2H-pyrazolo[3,4-d]pyridazine-4-carboxylate 、 alkaline earth salt of/the/ methylsulfuric acid 在
potassium carbonate 作用下,
以
丙酮 为溶剂,
以14%的产率得到ethyl 2-(4-cyanobenzyl)-6-ethyl-6,7-dihydro-3-methyl-7-oxo-2H-pyrazolo[3,4-d]pyridazine-4-carboxylate