Phosphorus oxychloride → 3-Benzyl-5-chloro-8-methylpyrido[2,3-d]pyrimidine-4,7(3H,8H)-dione
Reaction equation
[CH2:1]([N:8]1[C:13](=[O:14])[C:12]2[C:15](O)=[CH:16][C:17](=[O:20])[N:18]([CH3:19])[C:11]=2[N:10]=[CH:9]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1.O=P(Cl)(Cl)[Cl:24]>>[CH2:1]([N:8]1[C:13](=[O:14])[C:12]2[C:15]([Cl:24])=[CH:16][C:17](=[O:20])[N:18]([CH3:19])[C:11]=2[N:10]=[CH:9]1)[C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][CH:3]=1Participants
3
Procedure
3-Benzyl-5-hydroxy-8-methylpyrido[2,3-d]pyrimidine-4,7(3H,8H)-dione (1.1 g, 3.88 mmol) was dissolved in excess POCl3 (5 mL) and subjected to microwave irradiation at 70° C. for 30 minutes. The POCl3 was removed in vacuo and the residue dissolved in DCM then quickly washed with saturated sodium bicarbonate solution until neutral pH was observed. The organic layer was dried over MgSO4 and evaporated to dryness to give 1.5 g of the title compound as a reddish brown solid (94%). [M+H] calc'd for C15H12ClN3O, 302; found, 302.