Synthesis of Fused sp-Enriched Imidazoles.

A synthetic approach to imidazoles annulated to saturated six-membered cycles featuring S, SO, NH, NCbz was developed. It was achieved by combining the Neber rearrangement and the Marckwald reaction. The Neber rearrangement applied to cyclic ketones allowed us to prepare in hundred gram quantities previously unknown α-amino ketones.

Reductive cleavage of annulated 5,6-dihydro-2-1,2,4-thiadiazine-1,1-dioxides: medium sized ring azasultams.

A novel method for synthesis of medium sized ring azasultams was proposed. It includes reductive cleavage with sodium cyanoborohydride of annulated 5,6-dihydro-2-1,2,4-thiadiazine-1,1-dioxides that were prepared in bulk quantities by an improved procedure consisting of reacting cyclic imidates with taurine followed by treatment with phosphorus oxychloride in the presence of DIPEA.