In a 8-mL screw-cap vial, a mixture of 4-(4′-amino-1,1′-biphenyl-4-yl)-2,2-dimethyl-4-oxobutanoic acid (60 mg, 0.20 mmol) and 2-bromo-5-nitro-1,3-thiazole (63.3 mg, 0.30 mmol) in 4 mL n-butanol was heated at 90° C. overnight. The solvent was removed under reduced pressure. The mixture was dissolved in 5 mL 1:4 MeOH/DMF and purified by reverse-phase HPLC to provide 8.9 mg (10%) of the desired product. 1H NMR (400 MHz, DMSO-d6) δ 11.55 (br s, 1H), 8.50 (s, 11H), 7.70-8.05 (m, 8H), 3.15 (d, 1H), 1.25 (s, 6H); LC-MS m/z 426.2 (MH+), ret. time 3.12 min.
