名称:
                                Synthesis of substituted 3,4-dihydro-2H-pyrido[3,2-b][1,4]oxazine as new scaffolds for potential bioactive compounds
                             
                            
                                摘要:
                                The title compounds having different substituents on the heterocyclic framework were prepared by several methods from 2-acetamido-3-hydroxypyridine. The condensation of 2-protected-amino-3-hydroxypyridine with 2-chloroacrylonitrile or ethyl 2,3-dibromopropionate provided in several cases two isomeric pyrido-oxazines. Whereas the reaction of 2-acetamido-3-hydroxypyridine with methyl 2,3-dibromopropionate or with alpha-halocarbonyl compounds gave exclusively the 2-substituted pyrido-oxazine, in a one-step operation. (c) 2005 Elsevier Ltd. All rights reserved.
                             
                                                            
                                    DOI:
                                    10.1016/j.tet.2005.11.071