Study On Synthesis Of Derivatives Of Morpholine

N-formylmorpholine was synthesized with phosphoric acid as catalyst, the product was characterized by FT-IR, and it was coincident with the standard IR spectrum of N-formylmorpholine. Its purity was over 99.8 % as tested by GC. The influences of main factors on the reaction were investigated and the optimum conditions were: materials molar ratio n(formic acid)︰n(morpholine) = 1.3︰1.0, reaction temperature 80～90℃, reaction time 8.0 h, under the conditions, the yield of N-formyl morpholine was over 89 %. Then, seven acidic ionic liquids were synthesized and used as catalyst in the synthesis of N-formylmorpholine, among which a reusable ionic liquid [HSO3-pmim]HSO4 was selected and characterized by FT-IR, NMR, et al, a green process for the synthesis of N-formylmorpholine was studied. The optimum conditions of the reaction catalyzed by [HSO₃-pmim]HSO₄ were as follows: materials molar ratio n(formic acid)︰n(morpholine)=1.15︰1.00, reaction temperature 85～95℃, reaction time 8.0 h. After used 7 times under the conditions, [HSO₃-pmim]HSO₄ did not consume obviously and the yield of N-formylmorpholine keeps over 81 % and the purity over 99 %.N-acetylmorpholine was synthesized and characterized by FT-IR, it was coincident with the standard IR spectrum of N-acetylmorpholine, the optimum conditions of the reaction were as follows: materials molar ratio n(acetic acid)︰n(morpholine) = 1.2︰1.0, reaction temperature 125～130℃, reaction time 6.0 h, catalyst dosage (morpholine/%)6 %. Under the conditions, the yield of N-acetyl- morpholine was over 88 % and the purity tested by GC over 99 %. N-methylmorpholine was synthesized and characterized by FT-IR, it was coincident with the standard IR spectrum of N-methylmorpholine. The influences of main factors on the reaction were investigated, the optimum conditions of synthesis of N-methylmorpholine were as follows: raw materials molar ratio n(formaldehyde)︰n(formic acid)︰n( Morpholine) = 1.3︰1.2︰1.0, reaction temperature 90℃, reaction time 4.0 h, under the conditions, the yield of N-methylmorpholine was over 90 % and the purity tested by GC over 98 %;N-methylmorpholine-oxide was synthesized and characterized by FT-IR, it was coincident with the standard IR spectrum of N-methylmorpholine-oxide. The optimum conditions of the reaction were as follows: materials molar ratio n(hydrogen peroxide)︰n(N-methylmorpholine) = 1.4︰1.0, reaction temperature 65～75℃, reaction time 6.0 h, under the conditions, the yield of N-methylmorpholine-oxide was over 92 % and the purity tested by GC over 99 %.