Cesium carbonate → 4-{4-[7-(2,6-Dichloro-phenyl)-5-methyl-benzo[1,2,4]triazin-3-ylamino]-benzenesulfonyl}-piperazine-1-carboxylic acid tert-butyl ester

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Reaction Steps

In a dry 25 mL round bottom flask, 7-(2,6-dichloro-phenyl)-5-methyl-benzo[1,2,4]triazin-3-ylamine (0.205 g, 0.672 mmol, 1 equiv), 4-(4-bromo-benzenesulfonyl)-piperazine-1-carboxylic acid tert-butyl ester (0.408 g, 1.01 mmol, 1.5 equiv), cesium carbonate (0.657 g, 2.02 mmol, 3 equiv); 4,5-bis(diphenylphosphino)-9,9-dimethyl xanthene (0.078 g, 0.134 mmol, 0.2 equiv) and tris(dibenzylideneacetone) dipalladium (0.0615 g, 0.067 mmol, 0.1 equiv) were combined. The reactants were flushed with argon, diluted with dioxane (20 mL) and outfitted with a reflux condenser. The reaction was heated to reflux for 2 hours, then filtered hot, and the solvents were evaporated. Purification on silica gel flash column provided desired product as a yellow solid (0.185 g, 44% yield). MS (ESI+): m/z=529.0 (M−100), LC retention time: 3.51 min. 1H NMR (DMSO-d6): δ 1.33 (s, 9H), 2.72 (s, 3H), 2.87 (m, 4H), 3.4 (m, 4H), 7.5 (m, 1H), 7.67 (d, J=8.7 Hz, 2H), 7.78 (m, 3H), 8.18 (d, J=1.7 Hz, 1H), 8.30 (d, J=8.8 Hz, 2H), 11.53 (s, 1H).

Provenance & Evidence