By extension, the derivatives are also referred to as oxazines; examples include ifosfamide and morpholine (tetrahydro-1,4-oxazine).Cinnabarine and cinnabaric acid are two naturally occurring dioxazines, being derived from biodegradation of tryptophan.[2] Dioxazines are pentacyclic compounds consisting of two oxazine subunits.Polybenzoxazines are a class of polymers formed by the reaction of phenols, formaldehyde, and primary amines which on heating to ~200 °C (~400 °F) polymerise to produce polybenzoxazine networks.[5] The resulting high molecular weight thermoset polymer matrix composites are used where enhanced mechanical performance, flame and fire resistance compared to epoxy and phenolic resins is required.
