Synthesis and Identification of some Benzoxazole Derivatives via Mannich Reaction

The p-Hydroxy benzyldehyde is one of the aromatic compounds which contains two important functional groups (OH, CHO). In this work, the p-hydroxy benzyldehyde has been introduced into different reactions. The first one involves the synthesis of ether via Williamson reaction,in which p-hydroxybenzyldehyd reacts with chloro acetic acid to afford compound (1), then compound (1) in presence of sodium bicarbonate gives the anion (2). Which reacts with propargyl bromide to give the acetylenic compound (3). The compound (3) in turn reacts with secondary amine via Mannich reaction to give the acetylenic amine(4a-f). Finally, the compounds (4a-f) undergo reaction with o-amino phenol to give benzoxazole derivatives (5a-f). The structure of synthesized compounds had been elucidated by the available physical and spectral data.