Pd(PPh3)2Cl2 (10 mg) in a 10 mL tube under Ar was treated sequentially with 2′-amino-6-bromo-1′-methyl-2-phenylspiro[chroman-4,4′-imidazol]-5′(1′H)-one (20 mg, 0.052 mmol) in 1,4-dioxane (1 mL), Cs2CO3 (2 N, 0.3 mL) and 4-fluoro-3-(trifluoromethoxy)phenylboronic acid (20 mg, 0.106 mmol). The mixture was heated at 120° C. under microwave reactor for 0.5 h. The reaction mixture was concentrated in vacuo to give the residue, which was purified by preparative TLC to give pure 2′-amino-1′-methyl-2-phenyl-6-(3-(trifluoromethoxy)phenyl)spiro[chroman-4,4′-imidazol]-5′(1′H)-one (3.32 mg, 14%). 1H-NMR (MeOD): 2.23 (m, 2H), 3.10 (s, 3H), 5.80 (d, 1H), 6.98 (m, 1H), 7.13 (m, 1H), 7.26 (m, 2H), 7.34 (m, 3H), 7.38 (m, 3H), 7.46 (m, 2H).
