反应详情

36.3 g of 3-methyl-5,6,7,8-tetrahydro-1H-pyrido[4,3-d]-pyrimidine-2,4-dione, 23 g of 1-chloro-2-methylsulfanylethane (97% pure), 17.4 g of lithium bromide and 27 g of ethyldiisopropylamine in 700 ml of dimethylformamide were stirred for 14 h at 50° C. After the reaction mixture had been concentrated under reduced pressure, the residue was taken up with 400 ml of water and 400 ml, of dichloromethane, the pH was adjusted to 8 with sodium bicarbonate, with stirring, and the mixture was worked up by extraction with dichloromethane and water. 23 g of 3-methyl-6-(2-methylsulfanylethyl)-5,6,7,8-tetrahydro-1H-pyrido[4,3-d]pyrimidine-2,4-dione were obtained from the combined dichloromethane phases after drying, concentration and recrystallization of the residue from isopropanol.

1. concentrationAfter the reaction mixture had been concentrated under reduced pressure
2. extractionthe mixture was worked up by extraction with dichloromethane and water