4-Formylmorpholine is widely used as a solvent and extracting agent for aromatics. It is used as a scrubbing agent for acidic gases. It is employed in the preparation of adenine hydrochloride labeled with 14C, 4-(trifluoromethyl)morpholine, 3-alkyl-2-chloro-5,6-dihydrobenzaldehyde and terphenyl dialdehyde. It plays an important role in the desulfurization of natural gas, synthetic gas, flue gas and gasoline.
Treatment of 4-formylmorpholine with sulphur tetrafluoride in the presence of potassium fluoride gives 4-(trifluoromethyl)morpholine in excellent yields. 4-Formylmorpholine reacts with series of 2-alkyl-2-cyclohexen-1-ones in the presence of POCl3 to give the corresponding 3-alkyl-2-chloro-5,6-dihydrobenzaldehydes and allylic alcohols (by-product).