反应详情

Following the General Procedure of Description 15 (Part B), The zinc insertion product of (6c) was used in situ to cross couple with commercial 3-iodo-4-methyl-aniline (1.21 g, 5.2 mmol) in the presence of tris(benzylideneacetone)dipalladium (Pd2(dba)3) (119 mg, 0.13 mmol, 2.5 mol-%) and tris(o-tolyl)phosphine (P(o-tol)3) (158 mg, 0.52 mmol, 10 mol-%) in anhydrous degassed DMF (6 mL). Filtration, aqueous work-up, and purification by silica gel column chromatography with an ethyl acetate (EtOAc)/hexane mixture (EtOAc/hexane=7:3, v/v) furnished 1.15 g (61% yield) of the title compound (6d) as a yellow viscous oil. Rf˜0.28 (EtOAc/hexane=1:1, v/v). 1H NMR (300 MHz, CDCl3): δ 6.91 (d, J=8.1 Hz, 1H), 6.50-6.46 (m, 2H), 5.20-5.10 (br. m, 1H), 4.18-4.00 (m, 1H), 3.24 (br. s, 2H), 2.88-2.78 (br. dd, 1H), 2.70 (dd, 1H), 2.44 (dd, J=15.4 Hz, 5.4 Hz, 1H), 2.36 (dd, J=15.4 Hz, 5.4 Hz, 1H), 2.22 (s, 3H), 1.45 (s, 9H), 1.40 (s, 9H) ppm. LC/MS: Rt=1.433 min; ESI (pos.) m/z=365.20 (M+H+)+.

1. customin anhydrous degassed DMF (6 mL)
2. filtrationFiltration, aqueous work-up, and purification by silica gel column chromatography with an ethyl acetate (EtOAc)/hexane mixture (EtOAc/hexane=7:3