Formaldehyde → Benzoxazines

Participants

Reaction Steps

A 500 mL flask was charged with resorcinol (33 g, 300 mmol), 3-amino-1-propanol vinyl ether (61 g, 600 mmol), and paraformaldehyde (38 g, 1260 mmol). Approximately 200 g of toluene was added and the mixture was heated to reflux. Reflux continued until water ceased to collect in the trap (about one hour). The reaction mixture was then cooled to room temperature. A large volume of solid byproduct formed in the reaction vessel. The toluene solution was decanted from the solid, and the remaining solid was washed with extra toluene. All of the toluene fractions were combined in a separatory funnel. The toluene solution was washed with a 5% NaOH solution, followed by a saturated NaCl solution. The toluene solution was dried with magnesium sulfate, and filtered over a small bed of neutral alumina. Removal of the solvent under reduced pressure produced about 50 g of an orange colored liquid (46% yield).

Provenance & Evidence