Boron tribromide → [2-(4-Trifluoromethylphenyl)-6-hydroxybenzo[b]thien-3-yl][4-[2-(1-piperidinyl)ethoxy]phenyl]methanone

Participants

Reaction Conditions

Reaction Steps

The product of Example 19 (480 mg, 0.89 mmol) was dissolved in anhydrous CH2Cl2 (15 mL), cooled to -78° C., and treated with a 1.0 M CH2Cl2 solution of boron tribromide (0.8 mL, 0.8 mmol). The mixture was allowed to warm to room temperature, stirred overnight, and treated with additional boron tribromide (1.75 mL, 1.75 mmol) in 2 portions. After 72 h, the mixture was diluted with 75 mL of water and extracted with CH2Cl2 (2×75 mL). The organic layers were washed with 2 N sodium hydroxide and the resultant aqueous layer was acidified and extracted with CH2Cl2 (75 mL). The combined organic layers were dried (Na2SO4), concentrated, and purified via radial chromatography (2:1:0.1 hexane:ethyl acetate:MeOH, under an ammonia atmosphere) to provide 110 mg (24%) of the title product as an amorphous green solid: 1H NMR d 1.45 (m, 2H), 1.63 (m, 4H), 2.57 (m, 4H), 2.79 (t, J=4.9 Hz, 2H), 4.08 (t, J=4.9 Hz, 2H), 6.59 (d, J=8.6 Hz, 2H), 6.77 (d, J=8.7 Hz, 1H), 7.15 (s, 1H), 7.33 (d, J=8.7 Hz, 1H), 7.42 (s, 4H), 7.64 (d, J=8.6 Hz, 2H), 8.18 (b, 1H); HRMS (FD+) m/e calc'd. for C29H27F3NO3S (MH+): 526.1664, found: 526.1669; Anal. calc'd for C29H26F3NO3S.H2O: C, 64.07; H, 5.20; N, 2.57. Found: C, 63.67; H, 5.12; N, 2.89.

Provenance & Evidence