Annulation of 1-(2-Aminoaryl)pyrroles, Ethers with Elemental Sulfur To Give 1,3,6-Benzothiadiazepine Derivatives through Double C-S Bond Formation and C-O Cleavage of Ethers.

An efficient three-component reaction of 1-(2-aminoaryl)pyrroles, ethers, and elemental sulfur for constructing N-heterocycle-fused 1,3,6-benzothiadiazepines under transition-metal-free conditions has been developed. Ethers act as both reactants and solvent in this reaction. The method proceeds efficiently over a broad range of substrates with good functional group tolerance.