Nitrogen → (5-{2-[(3',4',5'-Trihydroxy-biphenyl-2-carbonyl)-amino]-phenyl}-thiophen-2-yl)-acetic acid

Participants

Reaction Conditions

Reaction Steps

(The following reaction is done in an anhydrous N2 atmosphere.) Dissolve (5-{2-[(3′,4′,5′-Trimethoxy-biphenyl-2-carbonyl)-amino]-phenyl}-thiophen-2-yl)-acetic acid (86) (55 mg, 0.11 mmol) in anhydrous DCM (3.2 mL) at −78° C., add dropwise a 1M solution of BBr3 in DCM (730 μL, 0.73 mmol) and stir for additional 30 min at −78° C. After slowly warming up stir the reaction solution for additional 4 h at rt. Cool reaction mixture to 0° C., add dropwise water. Extract the mixture with EtOAc (3×), wash combined organic layer with brine and dry it with Na2SO4. Purify the crude product by preparative RP HPLC (gradient, water/CH3CN 95:5 to 5:95) to obtain (5-{2-[(3′,4′,5′-Trihydroxy-biphenyl-2-carbonyl)-amino]-phenyl}-thiophen-2-yl)-acetic acid (87) (10 mg, 18%) as a yellow solid. 1H NMR (400 MHz, CD3OD): 3.88 (s, 2H); 6.50 (s, 2H); 6.66 (d, 1H, J=3.5 Hz); 6.93 (d, 1H, J=3.5 Hz); 7.23 (t; 1H, J=7.3 Hz); 7.35 (t, 1H, J=7.6 Hz); 7.38-7.46 (m, 3H); 7.50 (t, 1H, J=7.3 Hz); 7.62 (d, 1H, J=8.0 Hz); 7.84 (d, 1H, J=8.0 Hz).

Provenance & Evidence