THE SYNTHESIS OF 3-ARYLAMINOMETHYL-2,4-DI HYDROXYACETOPHENONE OR YL-3-ARYL-3,4-DIHYDRO-5-HYDROXY-2H-1,3-BENZOXAZINE AND THEIR INTERCONVERSION

The Mannich reaction of 2, 4-dihydroxyacetophenone, 37% formaldehyde s olution and arylamines has been studied in ethanolic-HCl solution or 9 5% ethyl alcohol. Two different kinds of compounds are obtained. Five 3-arylamino-methyl-2, 4-dihydroxy-acetophenone (5) and five 8-acetyl-3 -aryl-3, 4-di-hydro-5-hydroxy-2H-1,3-benzoxazine (6) are prepared. All of them are first reported. The structures of 5 and 6 are deduced by elemental analysis, IR, H-1 NMR, MS and UV analysis. The interconversi on between 5 and 6 has also been realized successfully.