4-Azidobenzoic acid → 4-[4-(1H-indazol-3-yl)-1H-1,2,3-triazol-1-yl]benzoic acid

Participants

Reaction Steps

4-azidobenzoic acid (252 mg; 1.55 mmol; 1.1 eq.) and 3-ethynyl-1H-indazole (200 mg; 1.4 mmol; 1.0 eq.) were dissolved in 1,4-dioxane (3 mL). D-(−)-isoascorbic acid sodium salt (28 mg; 0.14 mmol; 0.1 eq.) followed by a solution of copper sulfate pentahydrate (7 mg; 0.03 mmol; 0.02 eq.) in water (0.75 mL) were added and the reaction mixture was stirred at 900 for 48 h. Reaction mixture was diluted with EtOAc and extracted with a NaOH (0.1N). Aqueous phase was filtered, acidified to pH 4-5 by addition of HCl (5N) and the precipitate thus obtained, was filtered, washed with water and dried under reduced pressure at 50° C. to afford the title compound as a white solid (453 mg, 100%). 1H NMR (300 MHz, DMSO-d6) δ 13.53 (s, 1H), 9.57 (s, 1H), 8.49 (d, J=8.1 Hz, 1H), 8.42-8.24 (m, 3H), 8.13-8.03 (m, 1H), 7.74 (d, J=8.4 Hz, 1H), 7.63-7.50 (m, 1H), 7.45-7.29 (m, 2H).

Provenance & Evidence