Evaluation of an enantioselective synthesis of 6-chloro-3,4-dihydro-2 H -1,2-benzothiazine-3-carboxylic acid 1,1-dioxide and its derivatives

Step-by-step evaluation of an enantioselective synthesis of ( S )- and ( R )-ethyl 3,4-dihydro-2 H -1,2-benzothiazine-3-carboxylates is described, starting from ( S )- and ( R )-methyl 2-acetamido-3-(3-chlorophenyl)propanoates as a source of chirality. A one-pot procedure for transesterification and cleavage of the N -acetyl group was developed to prevent racemization during the hydrolysis of the methyl ester group. It was demonstrated that the synthesized benzothiazines might serve as useful building blocks for enantioselective synthesis of pharmacologically active compounds. How to Cite Bluke, Z.; Sladek, M.; Abel, U.; Kauss, V. Chem. Heterocycl. Compd. 201 5 , 51 , 187. [ Khim. Geterotsikl. Soedin. 2015 , 51 , 187.] For this article in the English edition see DOI 10.1007/s10593-015-1679-4