反应详情

This urea was suspended in freshly distilled tetrahydrofuran (3 mL) and cooled in an ice-brine bath. Potassium tert-butoxide (1.0 M in tetrahydrofuran; 0.64 mL; 0.64 mmol) (Aldrich) was added dropwise to the suspension over 5 minutes. The solid went into solution as the potassium tert-butoxide was added. After stirring for an additional 15 minutes in the cold, the reaction mixture was filtered through a bed of silica gel (1.75 g), eluting with 1:1 ethyl acetate-hexanes and then ethyl acetate. Purification by flash chromatography (Biotage 40S; 40:60 to 50:50 ethyl acetate-hexanes) gave (±)-7-chloro-3-(2-fluoro-4-methoxy-phenyl)-4-methyl-1-phenyl-3,4-dihydro-1H-pyrimido[4,5-d]pyrimidin-2-one. (Yield 0.22 g; 38% overall for two steps).

1. temperaturecooled in an ice-brine bath
2. additionwas added
3. filtrationwas filtered through a bed of silica gel (1.75 g)
4. washeluting with 1:1 ethyl acetate-hexanes
5. customPurification by flash chromatography (Biotage 40S; 40:60 to 50:50 ethyl acetate-hexanes)