Phosphorus oxychloride → Ethyl 4-chloro-2-(pyrimidin-2-yl)pyrimidine-5-carboxylate

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Reaction Steps

A suspension of 1.62 g (6.5 mmol) 4-hydroxy-[2,2′]bipyrimidinyl-5-carboxylic acid ethyl ester in 16 ml POCl3 was heated at reflux for lh. The solution was cooled to RT and poured into 100 ml ice-water. The pH of the solution was adjusted to 8 with sat. NaHCO3-solution. The water phase was extracted three times with 80 ml CH2Cl2. The combined organic phases were dried (Na2SO4), filtered and evaporated. The residue was purified by chromatography (SiO2, CH2Cl2/MeOH 95:5) to give 1.43 g (82%) 4-chloro-[2,2′]bipyrimidinyl-5-carboxylic acid ethyl ester as a light brown solid, MS (EI): 264.1 (M+).

Provenance & Evidence