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

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Reaction Steps

A suspension of 4.78 g (19.5 mmol) 4-hydroxy-2-pyridin-4-yl-pyrimidine-5-carboxylic acid ethyl ester in 20 ml POCl3 was heated at reflux for 1 h. 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 (MgSO4), filtered and evaporated. The residue was purified by chromatography (SiO2, CH2Cl2/MeOH 40:1) to give 4.34 g (84%) 4-chloro-2-pyridin-4-yl-pyrimidine-5-carboxylic acid ethyl ester as a yellow solid, MS (EI): 263.1 (M+).

Provenance & Evidence