Diisopropylethylamine → 4-[3-(4-Chloro-phenoxy)-benzyl]-piperazine-1-carboxylic acid imidazo[1,2-a]pyridin-5-ylamide

Participants

Reaction Steps

To a solution of imidazo[1,2-a]pyridin-5-ylamine (56.0 mg, 0.421 mmol) in CH2Cl2 (2.0 mL) were added N,N′-disuccinimidyl carbonate (108 mg, 0.421 mmol) and DMAP (51.0 mg, 0.417 mmol). The reaction mixture was stirred at rt for 6 h, then treated with 1-[3-(4-chloro-phenoxy)-benzyl]-piperazine hydrochloride (158 mg, 0.420 mmol) and diisopropylethylamine (109 mg, 0.840 mmol) and stirred for an additional 16 h at rt. The reaction mixture was diluted with EtOAc and extracted with H2O then saturated aqueous NaCl. The organic layer was dried (MgSO4), and concentrated. The crude residue was purified (FCC, 2 N NH3 in MeOH/DCM) to give 4-[3-(4-chloro-phenoxy)-benzyl]-piperazine-1-carboxylic acid imidazo[1,2-a]pyridin-5-ylamide (90.0 mg, 46%). MS (ESI+): calcd for C25H24ClN5O2 m/z 461.17. found 462.2 (M+H)+. 1H NMR (d6-DMSO): 9.21 (br s, 1H), 7.57 (s, 1H), 7.54 (d, J=1.2, 1H), 7.47-7.35 (m, 4H), 7.23 (dd, J=9.0, 7.2, 1H), 7.15 (d, J=7.6, 1H), 7.06-7.01 (m, 3H), 6.94 (dd, J=8.1, 1.9, 1H), 6.73 (d, J=7.1, 1H), 3.54 (s, 2H), 3.52-3.45 (m, 4H), 2.46-2.40 (m, 4H).

Provenance & Evidence