o-Aminomethylderivatives of phenols. Part 3. Mechanistic investigation of a Mannich reaction of phenols with N-methylenealkylamines

摘要: The mechanism of the Mannich reaction phenols (1) with 1,3,5-trialkyl-hexahydro-1,3,5triazines (2) as a source N-methylenealkylamines (3) in organic solvent has been investigated. It determined that formation o-hydroxybenzylamine 4 and its subsequent quick transformation into benzoxazine 5 primary amine reversible 3 takes place first stage process. Then, yield slowly increases appropriately decreases result so far unreacted 1 slow aminolysis 5. In addition, benzyldiamine 6 is formed by-product (Scheme 1).