General procedure for the synthesis of 4-amino-6-chloro-5-fluoropyrimidine from 4,6-dichloro-5-fluoropyrimidine: 4,6-dichloro-5-fluoropyrimidine (1.67 g, 10.0 mmol), n-butanol (6 mL), and 28% aqueous ammonium hydroxide (12 mL) were added to a sealed tube and mixed well. The reaction mixture was heated at 90 °C for 2 hours. After completion of the reaction, it was cooled to room temperature and the precipitated white crystals were collected by filtration to afford the target product 4-amino-6-chloro-5-fluoropyrimidine (1.31 g, 89% yield). The product was analyzed by LC-MS (ESI), m/z: 147.9 [M+H]+.
