Hydrochloric Acid → HCID 42604469, compound

Participants

Reaction Steps

To a stirred mixture of acetic acid 3-(4-oxo-3,4-dihydro-thieno[3,2-d]pyrimidin-2-yl)-phenyl ester, 27, (1.72 g, 6.0 mmol) in MeCN (25 mL) under a nitrogen atmosphere was added POBr3 (8.6 g, 30 mmol) and the resulting mixture was heated at reflux for 2.5 h. The reaction mixture was quenched by pouring onto iced water (200 mL) and the aqueous layer was neutralized by addition of solid NaHCO3. The precipitate formed was collected by filtration and dried. The resulting tan solid (1.6 g) was dissolved in THF/MeOH (1:1 v/v, 20 mL). K2CO3 (1.76 g, 12.8 mmol) was added and the mixture stirred at rt for 3.5 h. The reaction mixture was diluted with H2O (20 mL), acidified to pH 3-4 with 2M HCl and extracted with EtOAc (2×100 mL). The combined organic extracts were dried (MgSO4), concentrated and purified by flash chromatography (70:30 hexanes/EtOAc as eluent) to afford the title compound, IVa, as a colourless solid (0.76 g; 41%).

Provenance & Evidence