To a solution of Example 7a (0.08 g, 0.2 mmol), in 2 mL dimethoxyethane/ethanol/water (7:2:3) was added 2,3-dimethylphenylboronic acid (0.036 g, 0.27 mmol), catalytic dichlorobis(triphenylphosphine) palladium(II) and 0.297 mL of 1M aqueous sodium carbonate. The contents were heated at 150 degrees for 30 minutes in a microwave. The reaction was diluted with ethyl acetate and washed with brine, dried over MgSO4, filtered, and concentrated. The residue was purified on silica gel using flash chromatography (gradient elution, ethyl acetate/hexane 0-50%). The material obtained (35 mg) after concentration of the fractions was purified by preparative HPLC on a Phenomenex Luna C8(2) 5 μm 100 Å AXIA column (30 mm×75 mm), eluting with a gradient of acetonitrile (A) and 0.1% trifluoroacetic acid in water (B), at a flow rate of 50 mL/min (0-0.5 min 10% A, 0.5-7.0 min linear gradient 10-95% A, 7.0-10.0 min 95% A, 10.0-12.0 min linear gradient 95-10% A) to give 9 mg of the title compound. 1H NMR (300 MHz, DMSO-d6) ppm 2.19-2.27 (m, 3H) 2.33 (s, 3H) 6.94-7.53 (m, 4H) 7.80 (d, J=9.52 Hz, 2H) 8.19-8.55 (m, 3H) 12.36 (s, 1H). MS (ESI+) m/z 333.9 (M+H)+.
