Potassium Hydroxide → 2-(2-isopropyl-2H-[1,2,4]triazol-3-yl)-4,5-dihydro-6-oxa-1,3a-diaza-benzo[e]azulen-8-ol

Participants

Reaction Conditions

Reaction Steps

Alternatively, 8-Bromo-2-(2-isopropyl-2H-[1,2,4]triazol-3-yl)-4,5-dihydro-6-oxa-1,3a-diaza-benzo[e]azulene (9.5 g, 25.4 mmol), 2-di-tert-butylphosphino-2′,4′,6′-triisopropylbiphenyl (855 mg, 2.0 mmol), tris(dibenzylideneacetone)dipalladium (0) (475 mg, 0.5 mmol) and potassium hydroxide (4.2 g, 76.2 mmol) were suspended in dioxane (29 mL) and water (15 mL). The suspension was degassed with nitrogen and the reaction mixture heated at 90° C. for 1 h. The reaction mixture was diluted with water (50 mL) and extracted with ethyl acetate (20 mL). The aqueous fraction was acidified to pH˜5 by addition of hydrochloric acid (1M) causing a precipitate to form. The suspension was extracted with ethyl acetate (3×15 mL). The combined organic extracts were dried (MgSO4), concentrated in vacuo. The resultant residue was triturated with diethyl ether to yield 490 as an orange solid (3.6 g, 46%). 1H NMR (400 MHz, DMSO-d6) δ 9.90 (1H, br s), 8.22 (1H, d, J=8.9 Hz), 7.88 (1H, s), 7.82 (1H, s), 6.61 (1H, dd, J=8.9, 2.6 Hz), 6.41 (1H, d, J=2.6 Hz), 5.90 (1H, sept, J=6.5 Hz), 4.49-4.39 (4H, m), 1.47 (6H, d, J=6.5 Hz)

Provenance & Evidence