[Synthesis]
General procedure for the synthesis of 8-chloro-1-iodo-3-isopropylimidazo[1,5-a]pyrazines from 8-chloro-3-isopropylimidazo[1,5-a]pyrazines: intermediate J (33 mg, 0.17 mmol) was dissolved in 0.18 mL of DMF and then added to a solution of N-iodosuccinimide (NIS, 39 mg, 0.17 mmol) dissolved in 0.6 mL of DMF. 0.17 mmol) solution. The reaction mixture was heated to 60 °C and the reaction was stirred at this temperature for 3 hours. After completion of the reaction, the mixture was cooled to room temperature. Subsequently, the reaction mixture was partitioned between 1 M Na2SO3 aqueous solution and dichloromethane. The aqueous layer was extracted three times (3X) with dichloromethane. All organic layers were combined, dried with anhydrous Na2SO4, filtered and concentrated in vacuum to give 34 mg (62% yield) of pure intermediate K. The product was characterized by 1H-NMR (300 MHz, CDCl3): δ 1.41 (d, 6H, J=6.9 Hz), 3.20-3.31 (m, 1H), 7.28 (d, 1H, J=5.1 Hz), and 7.65 (d, 1H, J=5.1Hz). The mass spectrum (ESI) showed (M+H)+ m/z of 322.1. |