N-Iodosuccinimide → 8-Chloro-3-cyclobutyl-1-iodoimidazo[1,5-a]pyrazine

Reaction equation

[Cl:1][C:2]1[C:3]2[N:4]([C:8]([CH:11]3[CH2:14][CH2:13][CH2:12]3)=[N:9][CH:10]=2)[CH:5]=[CH:6][N:7]=1.C1C(=O)N([I:22])C(=O)C1>CN(C=O)C.C(Cl)Cl>[Cl:1][C:2]1[C:3]2[N:4]([C:8]([CH:11]3[CH2:14][CH2:13][CH2:12]3)=[N:9][C:10]=2[I:22])[CH:5]=[CH:6][N:7]=1

Participants

Procedure

8-Chloro-3-cyclobutylimidazo[1,5-a]pyrazine (1058 mg, 5.1 mmol) and NIS (1146 mg, 5.1 mmol) in anh DMF (10 mL) were stirred at 60° C. under Ar for 6 h. The reaction was diluted with DCM (˜400 mL), washed (H2O, brine), dried (Na2SO4) and concentrated under reduced pressure. Purification of the crude material by flash chromatography on silica gel (50 g cartridge, 10:1-8:1-7:1-6:1 hexanes:EtOAc) afforded the title compound as a pale yellow solid; 1H NMR (400 MHz, CDCl3) δ 7.51 (d, J=4.8 Hz, 1H), 7.26 (d, J=4.8 Hz, 1H), 3.75 (quintet, J=1.2 Hz, 8.4 Hz, 1H), 2.62-2.42 (m, 4H), 2.32-1.98 (m, 2H); MS (ES+): m/z 334.0 (100) [MH+]; HPLC: tR=3.38 min (OpenLynx, polar—5 min).