Acetic Acid → 3-(1H-benzoimidazol-2-yl)-6-(3-methoxy-4-methoxymethoxy-phenyl)-1H-indazole

Participants

Reaction Steps

6-(3-Methoxy-4-methoxymethoxy-phenyl)-1H-indazole-3-carbaldehyde (from Example 1(a), step (vi)) (20 mg, 0.064 mmol, 1 equiv) was dissolved in degassed 1:1 MeOH-water (0.7 mL) and was treated with acetic acid (19 μL, 5 equiv), 1,2-diaminobenzene (8.3 mg, 1.2 equiv) and copper(II) acetate (18 mg, 1.4 equiv) at 23° C. The mixture stirred for 30 min, was diluted with ethanol (3 mL) and water (2 mL) and was treated with a bubbling stream of SH2 for 3 min, which gave a black precipitate. The mixture was allowed to stir for 12 h. The mixture was filtered and concentrated. Purification by silica gel chromatography (6:4 ethyl acetate-hexane) gave 3-(1H-benzoimidazol-2-yl)-6-(3-methoxy-4-methoxymethoxy-phenyl)-1H-indazole as a solid (14 mg, 54%); Rf sm 0.39, p 0.24 (ethyl acetate-hexane 6:4); 1H NMR (CDCl3) δ 8.69 (d, 1H, J=8 Hz), 7.70 (bs, 2H), 7.58 (s, 1H), 7.53 (d, 1H, J=8 Hz), 7.30–7.15 (m, 7H), 5.30 (s, 2H), 3.97 (s, 3H), 3.58 (s, 3H); MS (ES) [m+H]/z Calc'd 401. found 401. [m−H]/z Calc'd 399. found 399.

Provenance & Evidence