Phosphorus oxychloride → HCID 19604217, compound

Participants

Reaction Conditions

Reaction Steps

A suspension of 37 g (152 mmol) of methyl 4-(5-chloro-1,6-dihydro-6-oxopyridin-3-yl)-4-oxobutyrate in 230 ml of phosphorus oxychloride was heated at 75° C. for 25 hours. The phosphorus oxychloride was subsequently distilled off in vacuo. The pale red residue was taken up in 200 ml of dichloromethane, 100 ml of water was added, and the pH of the aqueous phase was brought to 8.5 using 30 percent sodium hydroxide solution. After phase separation, the aqueous phase was extracted using 100 ml of dichloromethane. The combined organic phases were treated with active charcoal and evaporated. The residue was recrystallized from 300 ml of diisopropyl ether and filtered at 2° C. The yield was 32.83 g of pale pink crystals. A further 1.76 g of product was obtained from the mother liquor in the form of crystals. The total product yield was 87 percent. The melting point of the product was 85.2° to 86° C. Other data concerning the product was:

Provenance & Evidence