5177-27-5

49845-33-2

5177-27-5

General procedure for the synthesis of 5-amino-2,4-dichloropyrimidine from 2,4-dichloro-5-nitropyrimidine: 2,4-dichloro-5-nitropyrimidine (1.0 eq.) and iron powder (6.0 eq.) were formulated in acetic acid to form a non-homogeneous reaction system at a concentration of 0.4 M, and the reaction was carried out for 14 hours at room temperature with vigorous stirring. Upon completion of the reaction, the reaction mixture was thermally filtered through a diatomaceous earth pad to remove insoluble impurities. The filtrate was washed with methanol (MeOH) and the volatile solvent was subsequently evaporated under reduced pressure. The resulting residue was dissolved in ethyl acetate (EtOAc) and washed sequentially with saturated sodium carbonate (Na2CO3) solution and saturated sodium chloride (NaCl) solution to remove acidic impurities and salts. The organic phase was dried over anhydrous magnesium sulfate (MgSO4), filtered and concentrated under reduced pressure to afford the target product 5-amino-2,4-dichloropyrimidine in 80% yield. The product was analyzed by liquid chromatography-mass spectrometry (LCMS), showing a molecular ion peak (MH+) of 157.0 and a retention time (Rt) of 1.85 min.