Facile preparation of tetrahydro-5H-pyrido[1,2,3-de]-1,4-benzoxazines via reductive cyclization of 2-(8-quinolinyloxy)ethanones and their antioxidant activity

Pd/C-catalyzed reductive cyclization of 1-aryl-2-(8-quinolinyloxy)ethanones opens a facile access to the title compounds in good yields. The scope of this reductive cyclization is explored and the antioxidant activities of the products are studied.