Hydrochloric Acid → 2-Phenyl-1H-indene

Participants

Reaction Steps

A solution of 2-indanone (13.47 g, 102 mmol) in anhydrous benzene (100 mL) is added to phenylmagnesium bromide (3.0 M in diethyl ether, 50.9 mL, 153 mmol) at 5° C. over 2.5 hours. The reaction was allowed to warm to room temperature over 30 minutes. The solution was cooled to 0° C. and 150 mL of water are added. The resultant mixture was diluted with 200 mL of hexanes, neutralized with 5 M HCl, and washed with brine (2×100 mL). The aqueous layer was extracted with hexanes (2×50 mL), and the combined organic layers were dried (MgSO4), filtered, and the solvent removed in vacuo from the filtrate to yield a brown oil. This oil and p-toluenesulfonic acid (0.50 g) were dissolved in benzene (250 mL) in a round-bottom flask below a Soxhlet extractor containing 4 Å molecular sieves. After refluxing for 2.5 hours, the solution was filtered and cooled to 5° C. overnight. The product, a white flaky solid, was collected by filtration, and was washed with 50 mL of cold benezene. Additional product is obtained by concentrating the filtrate, cooling, and filtering the crystals (12.60 g, 64.3% yield). 1H NMR (400 Mhz, 20° C., CDCl3)δ7.62 (d, J=7.3 Hz, 2H), 7.47 (d, J=7.3 Hz, 1H), 7.39 (M, 3H), 7.27 (m, 2H), 7.22 (s,1H), 7.18 (t, J=7.4 Hz, 1H), 3.78 (S<2H). 13C{1H} NMR (100 Mhz, 20° C., CDCl3): δ146.3, 145.3, 143.1, 135.9, 128.6, 127.5, 126.5, 126.4, 125.6, 124.7, 123.6, 120.9, 38.9.

Provenance & Evidence