3-chloro-4-methyl-5,6,7,8-tetrahydro-pyrido[4,3-c]pyridazine 、
maleate dianion 、
邻氟苯甲酰氯 以whereby 3-chloro-6-(o-fluorobenzoyl)-5,6,7,8-tetrahydro-4-methylpyrido[4,3-c]pyridazine is obtained (M.P. 151°-153°)的产率得到3-chloro-6-(2-fluoro-benzoyl)-4-methyl-5,6,7,8-tetrahydro-pyrido[4,3-
c]pyridazine