Comparison of Base‐Promoted and Self‐Catalyzed Conditions in the Synthesis of Isocyanates from Amines Using Triphosgene

Abstract

Comparison of base‐promoted and self‐catalyzed conditions for the synthesis of isocyanates from amines and triphosgene shows no advantage in using an amine base in the majority of cases. The workup and isolation of the product is simplified under base‐free conditions. Yields of between 50 and 90% after distillation were common. Only acid‐sensitive substrates need a base catalyst.

Keywords:

• amines
• isocyanates
• triphosgene

Acknowledgments

The financial support of AWE and discussions with Norman Godfrey (AWE) are gratefully acknowledged.