Boron trifluoride etherate → (+)-1-[3-Methoxy-6-[4-(2-piperidin-1-yl-ethoxy)-phenyl]-6h-benzo[c]chromen-8-yl]-ethanone

Participants

Reaction Conditions

Reaction Steps

The compound from Step G (1.66 g, 3.2 mmol) was dissolved in CH2Cl2 (90 mL) and cooled to −78° C. Et3SiH (3.1 ml, 19.2 mmol) and BF3-Et2O (2.6 ml, 19.2 mmol) were added slowly under Ar. The mixture was stirred at −78° C., then at room temperature overnight. Saturated NaHCO3 (100 ml) was added and the mixture extracted three times with ethyl acetate (150 ml). The combined organic layer was washed with brine (100 ml) and dried over MgSO4. The solvent was removed and the crude product was chromatographed on silica gel with 7% CH3OH/CH2Cl2 to yield a fraction containing a mixture of the title compound along with side products and a fraction containing 0.52 g (32%) of the title compound. 1H-NMR (400 MHz, CDCl3) δH 1.42 (2H, m, NCH2CH2CH2), 1.59 (4H, m, NCH2CH2CH2), 2.50 (7H, m, NCH2CH2CH2 and COCH3), 2.76 (2H, m, NCH2CH2O), 3.77 (3H, s, OCH3), 4.08 (2H, m, NCH2CH2O), 6.14 (1H, s, Ph2CHO), 6.50 (1H, s, ArH), 6.61 (1H, d, ArH), 6.86 (2H, d, ArH), 7.22 (2H, d, ArH), 7.45 (1H, s, ArH), 7.66 (1H, d, ArH), 7.72 (1H, d, ArH), 7.93 (1H, d, ArH).

Provenance & Evidence