A one-pot synthesis of pyrido[2,3-b][1,4]oxazin-2-ones.
Pyrido[2,3-b][1,4]oxazin-2-ones are conveniently prepared in excellent yields by a one-pot annulation of N-substituted-2-chloroacetamides with 2-halo-3-hydroxypyridines with use of cesium carbonate in refluxing acetonitrile. The key transformation features a Smiles rearrangement of the initial O-alkylation product and subsequent cyclization.
D000081:Acetamides / Q000737:chemistry; D010078:Oxazines / Q000138:chemical synthesis*; D011725:Pyridines / Q000138:chemical synthesis* / Q000737:chemistry
D000081:Acetamides; D010078:Oxazines; D011725:Pyridines