Boron trifluoride etherate → HCID 22401272, compound

Participants

Reaction Conditions

Reaction Steps

To a solution of Compound 228 (7.0 g, 12.16 mmol) in wet CHCl3 (100 mL) was added BF3.OEt2 (7.48 mL, 60.82 mmol). The mixture was stirred at 25° C. (1. 5 hours) until TLC indicated complete conversion of Compound 228. Silica gel (10.0 g) was added to the reaction mixture followed by stirring at 25° C. for another 12 hours. Silica gel was filtered off through Celite and washed with ethyl ether (100 mL). The solvent was removed in vacuo, and the residue was purified by flash column chromatography (silica gel, 10 percent ethyl ether in benzene) to provide Compound 229 (3.91 g, 73 percent). A more polar component (about 1.0 g) was also isolated which could not be converted to Compound 229 in the presence of silica gel for prolonging reaction time. Compound 229: white solid; mp 140°-142° C.; Rf =0.44 (silica, 10 percent ethyl ether in benzene); IR (CHCl3) νmax 3305, 2977, 1737 (shoulder), 1720, 1705, 1684, 1607, 1577, 1495, 1382, 1306, 1201, 1178, 1122 cm-1 ; 1H NMR (300 MHz, CDCl3) δ 8.25 (d, J=8.7 Hz, 1 H, H1), 7.43-7.35 (m, 3 H, H4 and aromatic), 7.28-7.16 (m, 3 H, aromatic), 6.98 (dd, J=8.7, 2.4 Hz, 1 H, H2), 5.86 (d, J=2.4 Hz, 1 H, H6), 2.87-2.51 (m, 4 H, H7 and H9 ), 2.26 (d, J=2.4 Hz, 1 H, acetylenic), 2.24-2.08 (m, 2 H, H8), 1.33 (s, 9 H, COC(CH3)3); MS (FAB+) m/e (rel intensity) 444 (M+H, 82), 350 (15), 266 (20), 238 (15); HRMS for C27H26NO5 (M+H), calcd 444.1811, found 444.1842.

Provenance & Evidence