Potassium Carbonate → 3-(1,3-Benzodioxol-5-yl)-6-propoxy-1H-inden-1-one

Participants

Reaction Conditions

Reaction Steps

A 1 L three-necked flask equipped with mechanical stirrer was charged with DMF (1.5 L), PPh3 (3.6 g, 13.7 mmol), K2CO3 (67.5 g, 0.489 mol), PdCl2 (0.855 g, 4.82 mmol) and 3-(1,3-Benzodioxol-5-yl)-1-(2-bromo-5-propoxyphenyl)-2-propen-1-one (75 g, 0.193 mol). Upon purging the solution with nitrogen, heat the mixture at 110° C. for 0.5 h, cool to 40° C., concentrate to 1/2 volume (57° C., 40 mm Hg), and add H2O (750 ml) and stir the reaction mixture at room temperature for 1 h. Filter the precipitate and wash with H2O (500 mL). Transfer the wet solid (62 g) to a 1 L 3-necked flask, add EtOAc (500 ml) and 20% KSCN solution (250 mL) and heat the biphasic mixture to 65° C. for 1 h. Remove the aqueous layer, wash the organic layer with brine (2×250 mL), dry over MgSO4 and concentrate in vacuo. Slurry the crude solid in iPrOAc/iPrOH (200 ml, 1:1) and stir for 1.5 h at 5° C. Filter the product, wash with cold iPrOH (50 ml, 0° C.) and air dry to afford 3-(1,3-Benzodioxol-5-yl)-6-propoxy-1H-inden-1-one as an orange solid (43 g, 73% yield): mp 99.0-101.0° C.; 1H NMR δ 7.3-7.2 (m, 3 H), 7.1 (m, 2 H), 6.9 (d, J=8.1 Hz, 1 H), 6.75 (dd, J=2.5, 8.2 Hz, 1 H), 6.05 (s, 1 H), 5.8 (s, 1 H), 3.95 (t, J=6.6 Hz, 2 H), 1.8 (quintet, J=7.8 Hz, 2 H), 1.05 (t, J=7.4 Hz, 3 H).

Provenance & Evidence