Efficient Synthesis of 1,5‐Benzodiazepines Mediated by Sulfamic Acid under Neat Condition or in Solution

Abstract

2,3‐Dihydro‐1H‐1,5‐benzodiazepines have been synthesized in good to excellent yield from direct condensations of o‐phenylenediamines with ketones promoted by sulfamic acid at room temperature under neat condition or in acetonitrile.

Keywords:

• 1,5‐benzodiazepine
• condensation
• ketone
• o‐phenylenediamine
• sulfamic acid

Acknowledgment

This work was supported by the Major Basic R & D Program of China (Grant No. 2003CB716004).