Phosphorus oxychloride → (+/-)-2,4-Dichloro-5-(1-chloroethyl)-pyrimidine

To a solution of (±)-1-(2,4-dichloro-pyrimidin-5-yl)-ethanol (1.27 g, 6.60 mmol) (from Example 1a supra) in phosphorus oxychloride (5.0 mL, 53.11 mmol) (Aldrich), at 0° C., was added diisopropylethyl-amine (2.60 mL, 14.78 mmol) (Aldrich). The reaction was stirred at 0° C. for 5 minutes, at ambient temperature for 15 minutes and then at 115° C. for 3 hours. The reaction was cooled to room temperature, diluted with toluene (10 mL) and the mixture was then poured into ice (15 g). After stirring for 10 minutes, the layers were separated and the aqueous extract was back washed with toluene. The combined organic extracts were dried over anhydrous sodium sulfate, filtered, and concentrated. Purification by flash chromatography (Biotage, 40M, 10:90 to 15:85 ethyl acetate-hexanes gradient) gave (±)-2,4-dichloro-5-(1-chloroethyl)-pyrimidine as an oil. (Yield 1.233 g; 88.3%).