57473-32-2

Light Yellow Solid

General procedure for the synthesis of 5,7-dichloroimidazo[1,2-a]pyrimidines from 5,7-dihydroimidazo[1,2-A]pyrimidines: imidazo[1,2-a]pyrimidine-5,7-diol (4 g, 26.49 mmol) was dissolved in phosphorus trichloride (POCl3, 50 mL) and heated to a temperature of 90 °C for 4 hours. Upon completion of the reaction, the mixture was cooled to room temperature and concentrated under reduced pressure to remove excess POCl3. The residue was quenched with saturated sodium bicarbonate (NaHCO3) solution (100 mL) and subsequently extracted with ethyl acetate (EtOAc, 2 x 60 mL). The organic phases were combined, washed with brine (30 mL), dried over anhydrous sodium sulfate (Na2SO4), filtered and concentrated under reduced pressure to afford the target compound 5,7-dichloroimidazo[1,2-a]pyrimidine (3.5 g, 71% yield) as an off-white solid. The product was characterized by 1H NMR (400 MHz, DMSO-d6): δ 8.07 (d, J=1.6Hz, 1H), 7.86 (d, J=1.6Hz, 1H), 7.69 (s, 1H); LCMS (mass spectrometry) analysis showed molecular ion peaks m/z: 187.9 ([M+H]+).

[1] Patent: WO2018/48930, 2018, A1. Location in patent: Paragraph 00337
[2] Patent: EP1666468, 2006, A1. Location in patent: Page/Page column 64