Formic Acid → 4-[4-(4-Fluorophenyl)-1,3-oxazol-5-yl]pyridine

Participants

Reaction Steps

A solution of 2-bromo-1-(4-fluoro-phenyl)-2-pyridin-4-yl-ethanone hydrobromide (10 g, Reference Example 9) in acetonitrile (100 ml) at 0° C. was treated with formic acid (10 ml) followed by triethylamine (35 ml). The solution was stirred at room temperature for 16 hours and urea (4 g) was added together with formic acid (100 ml). The resulting mixture was refluxed for 6 hours with concomitant removal of the acetonitrile [with a Mc Intire head]. The solvent was then evaporated, the residue taken up into ethyl acetate and the grey solid discarded. The solvent was evaporated and the resulting gum was dissolved in water (100 ml) and the solution basified to pH 11 by addition of sodium hydroxide pellets. The resulting solid was filtered and subjected to flash chromatography on silica eluting with ethyl acetate to give the title compound as a white solid. MS: 241 [MH+]. RF=0.34 (ethyl acetate, determined by thin layer chromatography on silica).

Provenance & Evidence