Synthesis of Novel Dispiro 1,4-Benzothiazine Hybrid Heterocycles Through 1,3-Dipolar Cycloaddition

<div><p></p><p>The 1,3-dipolar cycloaddition of azomethine ylides generated in situ from the reaction of acenaphthylene-1,2-dione or isatins and α-amino acids to (E)-methyl/ethyl 2-(3-oxo-3,4-dihydro-2H-benzo[b][1,4]thiazin-2-ylidene)acetate led to the stereoselective formation of novel dispiro 1,4-benzothiazine hybrid heterocycles in good yields.</p>