Yield:-

Reaction Conditions:

with trichlorophosphate at 90; for 1 h;

Steps:

A suspension of 5-bromopyrimidone hydrobromide (1.0 g, 3.9 mmol) in phosphorous oxychloride (4 mL) was heated at 90 ⁰C for 1 h then cooled 0 ⁰C. The mixture was filtered, washed with POCI₃ (2 x 2 mL) to furnish the title compound as a cream solid(388 mg). This compound was unstable to air and was used immediately in the next step.

References:

WO2010/41054,2010,A1 Location in patent:Page/Page column 39-40