Sodium Dithionite → HCID 178453048, compound

Participants

Reaction Steps

To 2-[4-(2-Amino-5-bromo-3-nitro-pyridin-4-yl)-piperazin-1-yl]-N-thiazol-2-yl-acetamide (0.1 g, 0.22 mmol) in ethanol (5 ml) was added tert-butyl N-(3 formylbenzyl)carbamate (69 mg, 0.29 mmol) and 1M aq. Na2S2O4 (900 μL, 0.9 mmol). The reaction mixture was stirred at 80° C. for 16 h. tert-Butyl N-(3 formylbenzyl)carbamate (20 mg, 0.08 mmol) and 1M aq. Na2S2O4 (200 μL, 0.2 mmol) were added and the reaction mixture was stirred for another 5 h. The reaction mixture was concentrated in vacuo. The crude product was purified by chromatography on silica gel (100% dichloromethane to dichloromethane/ethyl acetate 1:1+1% methanol to 2% methanol in ethyl acetate). The isolated product was further triturated in ether, filtered, and dried in vacuo to give the title compound as a pale yellow solid (0.038 g, 27%); 1H-NMR (500 MHz, DMSO-d6) 1.39 (s, 9H, CH3 Boc), 2.78 (broad s, 4H, piperazine N(CH2)2), 3.40 (s, 2H, CH2CO), 3.70 (broad s, 4H, piperazine N(CH2)2), 4.22 (d, J=6.23 Hz, 2H, CH2NHBOC), 7.24 (d, 1H, J=3.60 Hz, thiazole 4-H or 5-H), 7.37 (d, J=7.21 Hz, 1H) and 8.02 (d, J=7.21 Hz, 1H) (4-ArH, and 6-ArH), 7.47 (m, 1H, 5-ArH), 7.49 (d, J=4.12 Hz, 1H, thiazole 4-H or 5-H), 8.11 (s, 1H, imidazo[4,5-b]pyridine 5-H), 11.89 (s, 1H, CONH), 13.54 (s, 1H, imidazo[4,5-b]pyridine NH);

Provenance & Evidence