A solution of 50 mg (0.166 mmol) of 1-6 and 25 mg (0.166 mmol) of 1-3 in 1.5 mL of dry NMP was heated with stirring at 90° C. under nitrogen. After 7 hours, the reaction was stopped and cooled. The reaction mixture was diluted with water, and extracted twice with EtOAc. The combined EtOAc extracts were washed with water and brine, dried, filtered, and concentrated in vacuo to give a crude oil. The crude product was purified by reversed phase preparative HPLC on a Gilson apparatus to give the title product as a white amorphous solid. MS M+1=430. 1H NMR (CDCl3): 4.77 (d, 2H), 5.60 (br m, 1H), 7.17 (q, 1H), 7.34 (m, 1H), 7.36 (m, 1H), 7.39 (m, 1H), 7.50 (d, 1H), 8.01 (dd, 1H), 8.53 (m, 1H), 10.5-11.5 (br, 1H).
