No abstract

A series of 1,3‐benzoxazine monomers were successfully synthesized by simple one‐pot and three‐component condensation of phenol, paraformaldehyde and varying types of primary aliphatic and aromatic amines in a molar ratio of 1 : 2 : 1 and in the presence of non‐acidic 2,3;4,5‐di‐O‐isopropylidene‐β‐D‐fructopyranose as an effective green carbohydrate based organocatalyst obtained from renewable feedstock. This multicomponent method provides a convenient fast approach for the construction of valuable 1,3‐benzoxazine monomers (8 examples) with moderate to excellent yields. The chemical structures of the synthesized benzoxazines were confirmed by FTIR,1H NMR,13C NMR spectra and elemental analysis.

In the present work, homonuclear coordination complex including Zn (II) and N-hexadecylimidazole ligand was used for the first time as a highly efficient homogeneous neutral organocatalyst for the synthesis of 3,4-dihydro-2H-1, 3-benzoxazine monomers. Therefore, N-alkyl or N-aryl substituted, both mono-benzoxazine and bis-benzoxazine, were successfully synthesized (21 examples) via Mannich-type condensation reactions. Effortlessly obtaining the pure product with high yields and the short reaction time makes this method more useful and advantageous than the common existing benzoxazine synthesis methods.