Synthesis of Chiral 2-(6,8-dichloro-4-methyl-1,1,3-trioxo-3,4-dihydro-1H-1λ6-benzo[1,2,4]thiadiazin-2-yl) Carboxylic Acids Derived from Enantiomeric Amino Acids

A series of new chiral 2-(6,8-dichloro-4-methyl-1,1,3-trioxo-3,4-dihydro-1H-1λ6-benzo[1,2,4]thiadiazin-2-yl) carboxylic acids 7a-g containing the chiral amino acid residue were synthesized by adopting the chemical transformations, which have not affected the chirality of the amino acid residue. No significant racemization of the chiral centre was observed during the synthesis of enantiomeric benzothiadiazine 1,1-dioxide derivatives from the corresponding D and L amino acids. Structures of all the newly synthesized compounds were determined by analytical and spectral data.