Studies on the Chemistry of Thienoanellated O,N- and S,N-Containing Heterocycles, 5: An Access to the Thienooxazin Ring System

Article abstract of DOI:10.1007/BF00812707

The reactivity of 5-acetyl-2-chloro-3-nitrothiophene with α-hydroxyesters is described.The influence of the solvent (DMF, tetrahydrofurane, toluene) and of the used base is discussed.These reactions provide an access to substituted thiophene derivatives, which are cyclized after reduction by iron powder/glacial acetic acid to give thieno<2,3-b><1,4>oxazine derivatives. - Keywords: Thieno<2,3-b><1,4>oxazines; Nucleophilic substitution.