4-Aminophenol → 2-p-Tolylbenzoxazole

Participants

Reaction Steps

68 g (0.5 mole of p-toluic acid were heated with 54.5 g (0.5 mole) of p-aminophenol and 2 g of boric acid in 750 ml of 1,2-methylnaphthalene and the water that formed was eliminated slowly by azeotropic destillation. After heating for 6 hours, 1 g of boric acid were added. After 12 hours, 16 ml of H2O (98%) passed over. The solvent was then removed until dryness, the residue was dissolved in 750 ml of ethanol, clarified with silica gel while still hot, and combined after filtration, while still hot, with 500 ml of H2O. After cooling and filtration with suction at room temperature and washing with aqueous ethanol, there were obtained 89.4 g (85.6% of the theory) of 2-p-tolyl-benzoxazole melting at 113° to 114° C. ##STR41##

Provenance & Evidence