Following the procedure of 3-[4-(1-amino-cyclobutyl)-phenyl]-6-fluoro-2-phenyl-chromen-4-one, {1-[4-(8-ethynyl-4-oxo-2-phenyl-4H-chromen-3-yl)-phenyl]-cyclobutyl}-carbamic acid tert-butyl ester was treated with TFA. The resultant free base was subjected to flash chromatography (SiO2, gradient 0 to 20% methanolic ammonia in DCM) to afford the title compound as a white solid (8 mg, 100%). 1H NMR (400 MHz, DMSO-d6): δ 8.08 (dd, J=7.8, 1.6 Hz, 1H), 7.97 (dd, J=7.6, 1.8 Hz, 1H), 7.48 (t, J=7.4 Hz, 1H), 7.42-7.28 (m, 7H), 7.14 (d, J=8.4 Hz, 2H), 4.65 (s, 1H), 4.01 (bs, 2H), 2.42-2.33 (m, 2H), 2.17-2.07 (m, 2H), 2.03-1.91 (m, 1H), 1.71-1.58 (m, 1H). LCMS (Method E): RT=3.64 min, [M+H]+=392.
