1,3-Dimethoxy-2-fluoro-4-iodobenzene → 4-(3-Fluoro-2,4-dimethoxyphenylethynyl)-1-(4-methoxybenzyl)-1H-pyrazole

Participants

Reaction Steps

To a stirred solution of 3-fluoro-2,4-dimethoxy-iodobenzene (200 mg, 0.71 mmol) and 4-ethynyl-1-(4-methoxy-benzyl)-1H-pyrazole (180 mg, 0.85 mmol) in dry MeCN (4 ml) and NEt3 (2 ml) was added Pd(Ph3P)2Cl2 (15 mg, 3 mol %) and the reaction vessel was evacuated and backfilled with N2 (g) three times. Copper (I) iodide (6 mol %) was added and the reaction rapidly became dark. Stirring was continued at room temperature for 3 hours, then the crude mixture was concentrated directly onto silica-gel and purified by flash chromatography (silica-gel, eluted sequentially with hexanes:EtOAc, 3:1, 2:1) to give the product as a resin that crystallised slowly upon standing in the freezer (230 mg, 89%). 1H-NMR (300 MHz, CDCl3) δ 7.66 (s, 1H), 7.50 (s, 1H), 7.19 (d, J=8.6 Hz, 2H), 7.10 (dd, J=8.7, 2.1 Hz, 1H), 6.87 (d, J=8.6 Hz, 2H), 6.61 (t, J=8.2 Hz, 1H), 5.24 (s, 2H), 4.01 (s, 3H), 3.87 (s, 3H), 3.79 (s, 3H).

Provenance & Evidence