Dimethylformamide → 3-phenyl-5,7-dimethyl-1-(4-bromobutyl)pyrido[2,3-d]-pyrimidin-2,4(1H,3H)-dione

Participants

Reaction Steps

A mixture comprising of 13.36 g 3-phenyl-5,7-dimethylpyrido[2,3-d]pyrimidine-2,4(1H,3H)-dione, 43.18 g of 1,4-dibromobutane, 10.37 g of anhydrous potassium carbonate and 150 ml of N,N-dimethyl-formamide was heated at 80° C. for 3 hours. After the completion of the reaction, the reaction mixture was poured into 600 ml of water. The resulting mixture was extracted with ethyl acetate and further with a small amount of dichloromethane. These extracts were combined, dried over anhydrous potassium carbonate and distilled under a reduced pressure to remove the solvent. The obtained residue was dissolved in a small amount of dichloromethane, columnchromatographed over silica gel column and eluted with dichloromethane. The eluate was concentrated under a reduced pressure and the residue was recrystallized from a dichloromethaneisopropyl ether solvent to give 13.06 g of 3-phenyl-5,7-dimethyl-1-(4-bromobutyl)pyrido[2,3-d]-pyrimidin-2,4(1H,3H)-dione having a melting point of 153.5° to 154.5° C., which serves as an intermediate (yield: 65%).

Provenance & Evidence