Potassium Phosphate, Tribasic → 3-((trimethylsilyl)ethynyl)-10,11-dihydro-5H-dibenzo[c,g]chromen-8(9H)-one

Participants

Reaction Conditions

Reaction Steps

A 300 mL flask equipped with an overhead stirrer and a reflux condenser under an atmosphere of nitrogen was charged with 3-chloro-10,11-dihydro-5H-dibenzo[c,g]chromen-8(9H)-one (10.0 g, 35.12 mmol), powdered anhydrous tripotassium phosphate (22.4 g, 105.4 mmol), XPhos (1.34 g, 2.81 mmol), and PdCl2(MeCN)2 (364 mg, 1.40 mmol). Acetonitrile (140 mL) was added followed by TMSacetylene (18 mL, 141 mmol). The mixture was heated to 65° C. After 6 h, the reaction was judged complete, and the mixture was cooled to 20° C. The mixture was filtered through a fitted funnel, and the filtercake was washed with acetonitrile. The filtrate was concentrated to about 150 mL under reduced pressure and extracted with heptane (50 mL, 3×100 mL). N-Acetyl cysteine (15 g) was added to the acetonitrile phase, and the mixture was agitated for 5 h at 45° C. The mixture was cooled to ambient temperature, filtered through a fitted funnel, and the filtercake was washed with acetonitrile. The filtrate was concentrated to about 120 mL under reduced pressure. Water (120 mL) was added and the mixture was agitated for 40 minutes at 45° C. and then cooled to ambient temperature. After 30 minutes the mixture was filtered through a fitted funnel to provide 3-((trimethylsilyl)ethynyl)-10,11-dihydro-5H-dibenzo[c,g]chromen-8(9H)-one (4.07 g, 33.4% yield) as a yellow solid: 400 MHz 1H NMR (CDCl3) δ 7.65 (d, J=8.1 Hz, 1H), 7.60 (s, 1H), 7.55 (s, 1H), 7.47 (dd, J=8.1, 1.4 Hz, 1H), 7.27 (s, 1H), 5.06 (s, 2H), 2.95 (t, J=6.1 Hz, 2H), 2.67-2.59 (m, 2H), 2.18-2.08 (m, 2H), 0.26 (s, 9H).

Provenance & Evidence