Citric Acid → 4-[5-(2-Fluorophenoxy)oxazolo[5,4-d]pyrimidin-2-yl]-2,6-dimethylphenol

Participants

Reaction Conditions

Reaction Steps

Under argon, 0.48 g of sodium hydride (60% in mineral oil) is added a little at a time to a solution of 1.12 ml of 2-fluorophenol in 40 ml of dry N,N-dimethylacetamide. After 30 min at room temperature, a suspension of 2.78 g of 4-(5-chlorooxazolo[5,4-d]pyrimidin-2-yl)-2,6-dimethylphenol (see Ex. 1 (c)) in 60 ml of dry N,N-dimethylacetamide is added, and the reaction is stirred at 60° C. for 1.5 h and at 80° C. for 5.5 h. Another 1.12 ml of 2-fluorophenol in 40 ml of dry N,N-dimethylacetamide were then reacted under argon with 0.48 g of sodium hydride (60% in mineral oil), and this mixture was added to the reaction at room temperature. After a further 9 h at 80° C., the reaction was cooled to room temperature and neutralized with 10% strength aqueous citric acid solution. The precipitated solid was filtered off with suction, washed with water and dried under reduced pressure at 45° C. This gave 3.37 g (96%) of the title compound, which was reacted without any further purification.

Provenance & Evidence