酸性离子液体催化合成N-甲酰吗啉

合成了7种酸性离子液体,并将其应用于催化合成N-甲酰吗啉的反应中,筛选出了一种可以重复使用的离子液体HSO3-pmim]HSO4,并对其进行了表征。以吗啉和甲酸为原料,离子液体HSO3-pmim]HSO4为催化剂,以一种环保的工艺合成了N-甲酰吗啉。用红外光谱对产品结构进行了分析表征,和N-甲酰吗啉标准谱图一致,用气相色谱测定产品质量分数大于99.8%。考察了影响反应的主要因素,确定了较佳反应条件:n(甲酸)∶n(吗啉)=1.15∶1,反应温度85~95℃,反应时间8.0 h。在该条件下HSO3-pmim]HSO4重复使用7次后,没有明显消耗,N-甲酰吗啉的收率大于81.3%。

Synthesis of N-Formylmorpholine Using Acidic Ionic Liquid as Catalyst

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.A green process for the synthesis of N-formylmorpholine was established using morpholine and formic acid in mole ratio 1∶1.15 reacting at 85~95 ℃ for 8.0 h in the presence of HSO3-pmim]HSO4 catalyst.Structure of 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.After used 7 times under the conditions,HSO3-pmim]HSO4 didn′t consume obviously and the yield of N-formylmorpholine keeps over 81.3 %.