Hydrochloric Acid → 8-(1-Ethyl-propyl)-3-(5-fluoro-3-methyl-benzofuran-2-yl)-2,6-dimethyl-imidazo[1,2-b]pyridazine

Participants

Reaction Steps

A THF solution (6 mL) of 5-fluoro-3-methyl-benzofuran (187.0 mg, 1.25 mmol) is cooled to −78° C. under N2 then treated with nBuLi (1.6 M in hexane, 1.0 mL, 1.6 mmol). After 10 min at −78° C., ZnCl2 (Aldrich, 0.5 M in THF, 3.0 mL, 1.5 mmol) is added. The resulting mixture is warmed to room temperature and treated with 8-(1-ethyl-propyl)-3-iodo-2,6-dimethyl-imidazo[1,2-b]pyridazine (212.4 mg, 0.62 mmol) and PdCl2(dppf)-CH2Cl2 complex (Aldrich, 60 mg, 0.073 mmol). The mixture is heated to 65° C. for 18 hours, then poured into H2O, acidified with 1 N HCl then extracted with ethyl acetate. The organic extract is ished with aq. brine, dried over Na2SO4, filtered, and concentrated. The crude product is purified by chromatography using hexane-ethyl acetate gradient (100% hexane to 20% ethyl acetate in hexane) to give the title compound as a solid (121.7 mg, 54% yield).

Provenance & Evidence