Boron tribromide → HCID 9823190, compound

Participants

Reaction Conditions

Reaction Steps

To a −5° C. solution of 6-methoxy-3-[4-(2-carboxyvinyl)benzoyl]-2-(4-methoxyphenyl)benzo[b]thiophene (900 mg, 2.0 mmol) in 40 mL of anhydrous CH2Cl2 under N2 was added BBr3 (0.76 mL, 8.0 mmol) slowly via syringe. After warming to 5° C., the mixture was stirred for 1 h at 5° C., then quenched by pouring into ice water (100 mL). The mixture was extracted with EtOAc (3×100 mL). The organic was then dried (Na2SO4) and concentrated in vacuo to a solid residue that was chromatographed (SiO2, 1% MeOH/CHCl3) to provide 730 mg (86%) of (E)-6-hydroxy-3-[4-(2-carboxyvinyl)benzoyl]-2-(4-hydroxyphenyl)benzo[b]thiophene as a yellow solid. mp 155-160° C. 1H NMR (DMSO-d6) δ12.55 (bs, 1H), 9.81 (s, 1H), 9.73 (s, 1H), 7.67 (s, 4H), 7.54 (d, J=16.0 Hz, 1H), 7.40 (d, J=9.0 Hz, 1H), 7.30 (d, J=2.5 Hz, 1H), 7.18 (d, J=9.0 Hz, 2H), 6.89 (dd, J=9.0, 2.5 Hz, 1H), 6.65 (d, J=9.0 Hz, 2H), 6.58 (d, J=16.0 Hz, 1H). FD mass spec: 416. Anal. Calcd. for C24H16O5S: C, 69.22; H, 3.87. Found: C, 68.95; H, 3.73.

Provenance & Evidence