still for framstellning of 4,5 - dichloro - 2 - phenyl - 3 (2h) - pyridazinon outbound transporter from 5 - chloro - 4 - amino - 2 - phenyl - 3 (2h) - pyridazinon

摘要

In a process for obtaining 4,5-dichloro-2-phenyl-3(2H)-pyridazinone from 5-chloro-4-amino-2-phenyl-3(2H)-pyridazinone the 5-chloro-4-amino-2-phenyl-3(2H)-pyridazinone is diazotized in a first stage in accordance with the following reaction: IMAGE (1) the compound (I) being obtained by dilution with water and filtration. In a second stage of the process the compound (I) is reacted with thionyl chloride in accordance with the following reaction: IMAGE (2) IMAGE the 4,5-dichloro-2-phenyl-3(2H)-pyridazinone being obtained by dilution with water and filtration.