Highly Regioselective N -2 Arylation of 4,5-Dibromo-1,2,3-triazole: Efficient Synthesis of 2-Aryltriazoles

Department of Chemical Development, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, Connecticut 06877, USA.
Organic Letters (Impact Factor: 6.14). 01/2009; 11(21):5026-5028. DOI: 10.1021/ol9019875

ABSTRACT Reaction of 4,5-dibromo-1,2,3-triazole with electron-deficient aromatic halides in the presence of potassium carbonate in DMF produces the corresponding 2-aryl-4,5-dibromotriazoles with high regioselectivity. Subsequent debromination of these triazoles by hydrogenation furnishes 2-aryltriazoles in excellent yields. Overall, this two-step process provides an efficient access to 2-aryl-1,2,3-triazoles.

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