Preparation of New Nitrogen-Bridged Heterocycles. 27. First Synthesis of 1,3-Thiazinoindolizine Derivatives

Article abstract of DOI:10.1246/bcsj.64.3289

Potassium 2-indolizinethiolates, generated in situ from the treatment of dialkyl 2-<(2-ethoxycarbonylethyl)thio>indolizine-1,3-dicarboxylates with potassium t-butoxide in N,N-dimethylformamide, reacted smoothly with various isothiocyanates and isocyanates with the elimination of alkoxide ions to give new heterocyclic compounds, alkyl 4(3H)-oxo-2-thioxo- and 2,4(3H)-dioxo-2H-1,3-thiazino<6,5-b>indolizine-10-carboxylates, in moderate to good yields.The structures of these 1,3-thiazino<6,5-b>indolizine derivatives were determined mainly by elemental analyses and spectral inspections, and the structural assignment was finally confirmed by the single crystal X-ray analyses of two compounds.