Phosphorus oxychloride → HCID 178478399, compound

Participants

Reaction Steps

A mixture of 1,3-azaphospholo[4,5-d]pyrimidin-7(1H,6H)-one (compound 12, 5.0 g, 32.66 mmol) and phosphorus oxychloride (125 mL) was heated under reflux with stirring for 50 min under an argon atmosphere. The reaction mixture was cooled to room temperature and unreacted phosphorus oxychloride was removed under reduced pressure at 25° C. The residual syrup was cooled to 0° C. and carefully neutralized with 2 N aqueous ammonium hydroxide. The precipitate formed was collected by filtration, washed with cold water (2×25 mL) and dried over P2O5 under vacuum, first at 25° C. and then at 100° C. The dry solid was crystallized from acetonitrile to yield 2.73 g (49%) of the title compound, mp>300° C. (became black at 190° C.). 1H nmr (DMSO-d6): δ 8.81 (s, 1 H, C5H), 9.36 (dd, 1 H, JC2H, NH =4.8 Hz, JC2H,P =39.4 Hz, C2H), and 13.68 (br s, 1 H, NH). Anal. Calcd. for C5H3ClN3P: C, 35.02; H, 1.76; Cl, 20.67; N, 24.50; P, 18.05. Found: C, 35.36; H, 2.08; Cl, 21.10; N, 24.21; P, 17.78.

Provenance & Evidence