Ethanol → tert-Butyl 4-(4-(6-bromo-7-(4-(thiazol-4-ylmethyl)piperazin-1-yl)-3H-imidazo[4,5-b]pyridin-2-yl)benzyl)piperazine-1-carboxylate

Participants

Reaction Conditions

Reaction Steps

To a mixture of 5-bromo-3-nitro-4-(4-(thiazol-4-ylmethyl)piperazin-1-yl)pyridin-2-amine (0.054 g, 0.13 mmol), EtOH (2.3 mL) and DMF (0.31 mL), tert-butyl-4-(4-formylbenzyl)piperazine-1-carboxylate (0.045 g, 0.15 mmol, 1.1 eq) was added followed by a freshly prepared aqueous solution of Na2S2O4 (1M; 0.40 mL, 0.40 mmol). The reaction mixture was heated at 85° C. for 24 h, then allowed to cool to room temperature and diluted with DCM and a few drops of aqueous NH3 until complete dissolution was observed. This solution was deposited on two preparative silica TLC plates and eluted with DCM/MeOH (v/v; 92:8). The title compound was obtained as a solid after trituration with diethyl ether (0.031 g, 35%); 1H-NMR (500 Mz, DMSO-d6): δ 1.39 (s, 9H, C(CH3)3), 2.34 (t, J=4.8 Hz, 4H), 2.65-2.72 (m, 4H), 3.30-3.36 (m, 4H), 3.55 (s, 2H, NCH2), 3.68 (m, 4H), 3.77 (s, 2H, NCH2), 7.47 (d, J=8.0 Hz, 2H, ArH, C6H4), 7.58 (d, J=2.0 Hz, 1H, thiazole 5-H), 8.14 (d, J=8.5 Hz, 2H, ArH, C6H4), 8.23 (s, 1H, imidazo[4,5-b]pyridine 5-H), 9.07 (d, J=2.0 Hz, 1H, thiazole 2-H), 13.47 (br s, 1H, imidazo[4,5-b]pyridine N—H); LC (method B)-MS (ESI, m/z) 2.50 min—653/655 [(M+H)+], Br isotopic pattern]. ESI-HRMS: Found: 653.2023, calculated for C30H38BrN8O2S (M+H)+: 653.2022.

Provenance & Evidence