Example 17 Synthesis of 2-aminopyrimidin-5-ylboronic acid III: [2-[(tert-butoxycarbonyl)amino]pyrimidin-5-yl]boronic acid (40.0 kg, 49 wt%, HPLC purity 82.0 mol) was dissolved in water (245 kg), and concentrated hydrochloric acid (39.6 L) was added slowly while keeping the temperature below 30°C. The reaction mixture was stirred for 12 hours and then cooled to 10°C. Subsequently, the pH of the mixture was adjusted to 6.5 with 50% aqueous sodium hydroxide solution while controlling the temperature below 15 °C and stirring was continued for 1 hour. After adding water (69.0 kg), the mixture was aged for 30 minutes. The resulting slurry was filtered and the filter cake was dried under vacuum at 50 °C to afford the target product 2-aminopyrimidin-5-ylboronic acid III (10.2 kg, 90% yield). The structure of the product was confirmed by 1H NMR (300 MHz, DMSO-d6): δ 8.50 (s, 2H), 7.97 (s, 2H), 6.74 (s, 2H).
![[2-[(tert-Butoxycarbonyl)amino]pyrimidin-5-yl]boronic acid](/CAS2/GIF/883231-25-2.gif)
