Formaldehyde → Benzoxazines

Participants

Reaction Steps

Hydroquinone (8.23 grams, 75 mmole), 3-amino-1-propanol vinyl ether (15.1 grams, 150 mmole), and toluene (100 mL) were placed in a 250 mL round bottom flask. Paraformaldehyde (9.0 grams, equivalent to 300 mmole of formaldehyde) was then added to the flask. The flask was then equipped with a magnetic stir bar, a Dean-Stark trap, and condenser. The mixture was stirred and heated to reflux under an argon blanket. A total of 5.2 milliliters (96% of theory) of water was collected in the trap after two hours reflux. The reaction mixture had turned black by this point. The toluene reaction solution was washed with two 50 mL aliquots of 5% aqueous sodium hydroxide, followed by one 50 mL aliquot of water. The toluene solution was passed over a bed of neutral alumina and then evaporated to yield 3.8 grams (14% of theory) of a viscous, light brown liquid.

Provenance & Evidence