Thesis is devoted to the development of a novel antagonists for the NMDA receptor glycine binding site (GlyB). The literature review covers publications about GlyB antagonists published over the past decade. A new class of ligands for glycine binding site has been identified based on 3,4-dihydro-2H-1,2-benzothiazine-3-carboxylic acid 1,1-dioxides and a method of their synthesis has been developed. Structure-activity relationship studies within the series have been performed. An assymetric synthesis of 3,4-dihydro-2H-1,2-benzothiazine-3-carboxylic acid 1,1-dioxides has been elaborated and affinity of both enantiomers has been evaluated. Published data on the synthesis of 3,4-dihydro-2H-1,2-benzothiazine 1,1-dioxides is reviewed. Elimination and reduction of hydroxy group of 4-hydroxy-1,1-dioxo-2H-1,2-benzothiazines has been evaluated as a potential synthetic approach to 2H-1,2-benzothiazine-3-carboxylic acid 1,1-dioxides and their 3,4-dihydro analogues.