Sodium Hydroxide → 2,7-Dichloroquinoline

Participants

Reaction Conditions

Reaction Steps

7-Chloroquinoline (2.2 g, 13.45 mmol) was dissolved in chloroform (100 mL) and treated with 3-chloroperoxybenzoic acid (3.32 g, 13.45 mmol). The reaction was stirred at 45° C. for 30 minutes after which the oxidation was deemed complete. Water (100 mL), 1 N sodium hydroxide (50 mL) and dichloromethane (200 mL) were added and the phases mixed and separated. The organic was dried with magnesium sulfate and evaporated to dryness under reduced pressure. The crude N-oxide was treated with phosphorus oxychloride (20 ml, 218 mmol) and heated at 110° C. After 5 minutes the chlorination was deemed complete and the solution evaporated to dryness under reduced pressure. The crude product was partitioned between water (50 mL), 1 N sodium hydroxide (50 mL) and ethyl acetate (200 mL). The organic phase was dried with magnesium sulfate and evaporated to dryness under reduced pressure. Purification using silica chromatography (hexane to ethyl acetate gradient) gave the desired 2,7-dichloroquinoline (0.98 g, 4.95 mmol, 36.8% yield).

Provenance & Evidence