Phosphorus oxychloride → 4,6-Dichloro-3-nitroquinoline
Reaction equation
[Cl:1][C:2]1[CH:3]=[C:4]2[C:9](=[CH:10][CH:11]=1)[N:8]=[CH:7][C:6]([N+:12]([O-:14])=[O:13])=[C:5]2O.O=P(Cl)(Cl)[Cl:18]>>[Cl:18][C:5]1[C:4]2[C:9](=[CH:10][CH:11]=[C:2]([Cl:1])[CH:3]=2)[N:8]=[CH:7][C:6]=1[N+:12]([O-:14])=[O:13]Participants
3
Procedure
11 g (48.97 mmol) of 6-chloro-3-nitro-quinolin-4-ol (step b) in 80 ml of POCl3 are heated under reflux for 5 h (tlc-control). The cool reaction mixture is poured slowly into 1.5 l of ice water. The title compound separates as a solid. The mixture is stirred for 15 min, the temperature not exceeding 0-5° C. The solid is filtered off, washed with water and dissolved in 200 ml ethylacetate. The organic phase is washed with a mixture of 200 ml of water and 38 ml of a 2 N sodium hydroxide solution, then again with water. After drying over MgSO4, the solvent is evaporated almost to dryness; hexane is added to the residue and the title compound is isolated by filtration as a dark-grey powder. This material is used in the next step without further purification.
Workup
- temperatureunder reflux for 5 h (tlc-control)