Phenylacetylene → 1-(5-Bromo-2-isopropoxyphenyl)-3-phenylprop-2-yn-1-one

Participants

Reaction Steps

To a stirred solution of phenyl-acetylene (0.27 ml, 2.46 mmol) in anhydrous THF (3 ml) 2M iPrMgCl in THF (1.25 ml) was added drop wise at 0° C. under N2. After stirring for 15 min, the solution of product of Step A (0.5 g, 2.06 mmol) in anhydrous THF (2 ml) was added drop wise and the mixture was stirred for 1 h at room temperature. The mixture was quenched with saturated NH4Cl and extracted with EtOAc (50 ml). The organic layer was washed with H2O, dried over MgSO4. and filtered. The filtrate was evaporated to dryness to give a creamy paste (0.59 g; 83%). [1H-NMR (CDCl3) 7.68 (d, 1H, J=2.49 Hz); 7.46-7.43 (m, 2H); 7.36 (dd, 1H, J=8.75, 2.54 Hz); 7.32-7.28 (m, 3H); 6.79 (d, 1H, J=6.77 Hz); 5.79 (d, 1H, J=5.23 Hz); 4.64-4.58 (m, 1H); 3.13 (d, 1H, J=5.91 Hz); 1.37 (d, 6H)]. This was dissolved in dioxane (10 ml) and MnO2 (1 g) was added to it. The resulting suspension was stirred for 6 h at reflux, then filtered through Celite and the solvent was evaporated to dryness to give the title compound (0.54 g, 76.5%), as light yellow paste. 1H-NMR (CDCl3) 8.00 (d, 1H, J=2.61 Hz); 7.61-7.52 (m, 3H); 7.44-7.35 (m, 3H); 6.88 (d, 1H, J=8.91 Hz); 4.68-4.60 (m, 1H); 1.36 (d, 6H).

Provenance & Evidence