Phosphorus oxychloride → Methyl 4-chloro-6-oxo-1-phenyl-1,6-dihydropyridazine-3-carboxylate
Reaction equation
[CH3:1][O:2][C:3]([C:5]1[C:10](O)=[CH:9][C:8](=[O:12])[N:7]([C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=2)[N:6]=1)=[O:4].P(Cl)(Cl)([Cl:21])=O>>[CH3:1][O:2][C:3]([C:5]1[C:10]([Cl:21])=[CH:9][C:8](=[O:12])[N:7]([C:13]2[CH:18]=[CH:17][CH:16]=[CH:15][CH:14]=2)[N:6]=1)=[O:4]Participants
3
Conditions
- Temperature
- 85 °C
Procedure
A mixture of 4-hydroxy-6-oxo-1-phenyl-1,6-dihydropyridazine-3-carboxylic acid methyl ester (3.83 g, 15.6 mmol) and phosphorous oxychloride (50 mL) was heated to 85° C. After 20 hours, the reaction mixture was concentrated under reduced pressure. The resulting residue was quenched with water. The precipitate was filtered and dissolved in EtOAc, dried (MgSO4) and concentrated under reduced pressure to yield 3.44 g (84%) of desired product.