2-Chloro-1,1-diethoxyethane → 6-Chloro-7-phenyl-imidazo[1,2-b]pyridazine

Beteiligte Stoffe

Reaktionsschritte

The mixture of 6-chloro-5-phenyl-pyridazin-3-yl-amine and 6-chloro-4-phenyl-pyridazin-3-yl-amine (20.2 g=0.1 mol) was suspended in 300 mL water and 30 mL THF. After addition of 32 mL (0.51 mol) chloracetaldehyde diethylacetal the reaction mixture was heated for five hours at reflux. Additional 32 mL (0.51 mol) chloracetaldehyde diethylacetal were added and heating was continued for another six hours. The reaction mixture was diluted with ethyl acetate and extracted three times. The organic phase was dried (sodium sulfate), filtrated and the solvent was removed. The residue was purified by chromatography (Biotage, eluents: ethyl acetate/hexane). 6.8 g (30.1%) of the title compound, 6-chloro-7-phenyl-imidazo[1,2-b]pyridazine, and 6.4 g (28.4%) of the regioisomer, 6-chloro-8-phenyl-imidazo[1,2-b]pyridazine, were obtained.

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