2-Amino-4-chloropyrrolo[2,3-d]pyrimidine

7355-55-7

84955-31-7

2-Amino-4-hydroxypyrrolo[2,3-d]pyrimidine (10.0 g, 66.6 mmol) was added to 100 mL of phosphorus oxychloride (POCl3) and the reaction was carried out at reflux for 2 hours. After completion of the reaction, the solvent was removed by rotary evaporator. After the reaction mixture was cooled to room temperature, it was slowly poured into 120 mL of ice water and the solid product was collected by filtration. The filter cake was washed with ice water and the pH of the filtrate was subsequently adjusted to 2 with ammonia solution and cooled in an ice bath for 2 hours to promote precipitation. The solid product was filtered again and washed sequentially with 10 mL of ice water and 30 mL of ether, resulting in 8.7 g of 2-amino-4-chloropyrrolo[2,3-d]pyrimidine in 78% yield.