反应详情

A mixture of the product of Step B (0.275 g; 0.681 mmol), Cl2Pd(PPh3)2 (0.058 g; 0.083 mmol); CuI (0.025 g; 0.13 μmol), anhydrous N,N-diisopropyl ethylamine (1 ml) in anhydrous DMF (5 ml) was cooled to −40° C., degassed under reduced pressure and saturated with dry N2. To it, propyne gas (0.5 g; 12.4 mmol) was added at −40° C. The reaction flask was sealed with septum and allowed to warm up to room temperature and stirred overnight at room temperature than evaporated to dryness under reduced pressure. The residue was purified by flash column chromatography (SiO2, hexane/ethyl acetate, 8:2) to give the title compound (0.171 g; 79% yield) as creamy solid. 1H-NMR (CDCl3) 1.21 (d, 6H, J=6.16 Hz); 2.00 (s, 3H); 3.86 (s, 3H); 4.43 (m, 1H, J=6.16 Hz); 6.79 (d, 1H, J=8.67 Hz); 7.14 (d, 1H, J=8.67 Hz); 7.72 (broad s, 1H).

1. customdegassed under reduced pressure and saturated with dry N2
2. customThe reaction flask was sealed with septum
3. customthan evaporated to dryness under reduced pressure
4. customThe residue was purified by flash column chromatography (SiO2, hexane/ethyl acetate, 8:2)