Tetrakis(triphenylphosphine)palladium(0) (32.9 mg) was added to a mixture of 2M aqueous sodium carbonate solution (0.428 mL), 9-bromo-3,4-dihydropyrido[2,1-c][1,2,4]thiadiazine 2,2-dioxide (150 mg) and biphenyl-4-ylboronic acid (135 mg) in 1,2-dimethoxyethane (5.701 mL). The reaction mixture was stirred under a nitrogen atmosphere at 100° C. overnight, added to water, and the mixture was extracted with ethyl acetate. The organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate/hexane, then ethyl acetate/methanol) to give the title compound (44.5 mg) as a pale-brown solid.
