1,8-Diazabicyclo(5.4.0)undec-7-ene → 5-phenylfuro[2,3-d]pyrimidin-4(3H)-one

Participants

Reaction Conditions

Reaction Steps

The title compound was prepared by the method of Dauzonne, D.; Adam-Launay, A. Tetrahedron 1992, 48, 3069-3080. 4,6-Dihydroxypyrimidine 161 (3.3 g, 29.4 mmol) and 160 (5.3 g, 26.7 mmol) were combined in EtOH (absolute, 110 mL) and the mixture was heated at 60° C. for 10 min to dissolve 161. DBU (8.06 mL, 53.9 mmol) was then added drop-wise. After addition of DBU the deep green-brown solution was heated at reflux for 3 h then at 60° C. over night. The deep red solution was then cooled to room temperature and concentrated to a thick red oil. Purification by flash chromatography (SiO2, gradient eluent: CH2Cl2 to 5% MeOH/CH2Cl2) to afford as an orange-red semisolid/oil. This material was triturated with 1.75:1 CH2Cl2/hexanes and solid 162 was isolated by Buchner filtration (−95% pure). Flash chromatography of the mother liquors afforded a second crop of solid 162 (>90% pure). The two crops were combined and concentrated to afford 162 as a pale orange solid (69% yield).

Provenance & Evidence