Shuo Yan

N-Formylation of Amines Using Molybdate Sulfuric Acid

Significance: Molybdate sulfuric acid (MSA) catalyzed the N-formylation of amines with orthoformates to give the corresponding formamide derivatives in up to 95% yield (19 examples). In the Nformylation of aniline with triethyl orthoformate, the catalyst was recovered by filtration and reused three times with a slight loss of catalytic activity (1st reuse: 87% yield, 3rd reuse: 80% yield). Comment: The catalytic activity of MSA was superior to that of the other catalysts (ZnO, ZrOCl2, MgBr2, ZnCl2, and H2SO4).The authors have reported previously the preparation of molybdate sulfuric acid and its application to the synthesis of phenazines and quinoxalines (Polycycl. Aromat. Compd. 2011, 31, 97). Selected examples: + MSA (2 mol%) EtOH, reflux, 40–450 min up to 95% yield (19 examples) R1 H N R2 RO H OR OR H N O R2 R1 (R = Me or Et)