Crystal structure of 1,2-bis-(6-bromo-3,4-dihydro-2 H-benz[ e][1,3]oxazin-3-yl)ethane: a bromine-containing bis-benzoxazine

Abstract

The title benzoxazine molecule, C₁₈H₁₈Br₂N₂O₂, was prepared by a Mannich-type reaction of 4-bromo-phenol with ethane-1,2-di-amine and formaldehyde. The title compound crystallizes in the monoclinic space group C2/c with a centre of inversion located at the mid-point of the C-C bond of the central CH₂CH₂ spacer. The oxazinic ring adopts a half-chair conformation. The structure is compared to those of other functionalized benzoxazines synthesized in our laboratory. In the crystal, weak C-H⋯Br and C-H⋯O hydrogen bonds stack the mol-ecules along the b-axis direction.

Keywords: C—H⋯Br and C—H⋯O hydrogen bonds; benzoxazines; crystal structure; phenolic resins.