p-Toluenesulfonic acid → Oxazolo(4,5-b)pyridine

Participants

Reaction Conditions

Reaction Steps

A mixture of 2-amino-3-hydroxy pyridine (25 g, 227 mmol), triethylorthoformate (75 ml) and p-toluenesulfonic acid (61 mg) was heated at 140° C. for 8 hours. Excess triethylorthoformate was removed under vacuum. The product was crystallized from ethyl acetate to yield 22.5 g of oxazolo[4,5-b]pyridine; H1NMR (DMSO-δ): 9.26 (1H, s), 8.78 (1H, d), 8.45 (1H, d), 7.7(1H, dd); MS: 120.8 (M+1).

Provenance & Evidence