A solution of 1-3 (90 mg, 0.211 mmol, 1.0 equiv) in DMF (2 ml) in a microwave vial was treated with the 3,5-dimethylphenyl boronic acid (34.7 mg, 0.232 mmol, 1.1 equiv), cesium carbonate (0.632 mL of a 1M solution in water, 0.632 mmol, 3.0 equiv), and PdCl2(dppf)-CH2Cl2 adduct (17.20 mg, 0.021 mmol, 0.1 equiv). The mixture was heated to 150° C. in a microwave reactor for 10 minutes. The mixture was cooled to room temperature and diluted with EtOAc. The organic solution was washed with sat. aq. NH4Cl, dried over Na2SO4, filtered and concentrated. The crude material was purified by gradient elution on silica gel (0 to 100% EtOAc in hexanes) to yield impure material which was precipitated from ether/hexanes and filtered. The solid was isolated to afford the product (1-4) as a tan solid. HRMS [M+H] C26H27N5O3 calc'd 453.2173. found 453.2178.
