Amines, primary benzoxazine synthesis

The polybenzoxazines (PBZs) provide a new class of phenolic resins that were first described by Ishida in 1998 (Ref. 15). Synthesis of the resins involves three components a phenol, a primary amine and formaldehyde. The first stage involves the formation of a multifunctional benzoxazine monomer Figure 23.30 a)). The monomer can then be ring-opened at elevated temperatures (160-220 C) to yield a polymeric stmcture (Figure 23.30(b)). 

An efficient one-pot, three-component synthesis of substituted 1,2,4-triazoles 164 has been reported from primary amines 161, dimethylamino acetals 162, and acyl hydrazides 163 <04OL2969>. 1,3-Benzoxazine 165 reacted with acyl hydrazides in refluxing methanol to give... 

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