5-Bromothiophene-3-carboxamide → HCID 59022988, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of [4-(4-methyl-piperazin-1-yl)-phenyl]-(5-tributylstannanyl-imidazo[1,2-a]pyrazin-8-yl)-carbamic acid tert-butyl ester (0.106 g, 0.15 mmol) in DMF (3 mL) is added 5-bromo-thiophene-3-carboxylic acid amide (0.062 g, 0.3 mmol) and tetrakis(triphenylphosphine)palladium(0) (0.018 g, 0.015 mmol). The solution is degassed and heated at 85° C. for 18 hours. The reaction mixture is diluted with ethyl acetate and washed with water (3×) and brine. The aqueous layers are backwashed with ethyl acetate and the organic layers are combined, dried (MgSO4), and concentrated. The crude mixture is then stirred in (1:1) TFA: dichloromethane (3 mL) for 2 hours at room temperature. The resulting solution is diluted with ethyl acetate and washed with water, sat. NaHCO3 and brine. The aqueous layers are backwashed with ethyl acetate and the organic layers are combined, dried (MgSO4), and concentrated. The crude material is purified by flash column chromatography using 99:1 and 95:5 DCM:NH3 (7M in MeOH), to give 5-{8-[4-(4-methyl-piperazin-1-yl)-phenylamino]-imidazo[1,2-a]pyrazin-5-yl}-thiophene-3-carboxylic acid amide (0.013 g, 20%) as a yellow solid. LCMS: Rt 2.79 min, (93.3%), m/z (APCI) 434 (M+H)+; 1H-NMR (400 MHz, d6-DMSO) δ (ppm) 2.26 (3H, s), 2.48-2.53 (4H, m), 3.14 (4H, m), 6.96 (2H, d), 7.42 (1H, br s), 7.61 (1H, s), 7.78 (1H, s), 7.82 (2H, d), 7.92 (1H, s), 7.99 (1H, br s), 8.21 (1H, s), 8.31 (1H, s), 9.61 (1H, s).

Provenance & Evidence