One-pot synthesis of new fused 4,5-bridged 1,2,5-triazepine-3,6-diones, 1,2,5-triazepine-3,7-diones heterocycles by Petasis reaction.

The one pot synthesis of a new fused 1,2,5-triazepine-3,6-diones, 1,2,5-triazepine-3,7-diones heterocyles has been described via Petasis reactions. These heterocycles might be suitable for elaboration into larger peptides at amino termini. The scope and limitations of this method have been examined.