New Chiral Benzothiazine Ligand and Its Use in the Synthesis of a Chiral Receptor

Abstract

The development of chiral ligands to direct the course and stereoselectivity of many catalytic asymmetric reactions is an important area of interest for many research groups. As part of a program examining the chemistry of 2,1-benzothiazines, we have prepared a new chiral benzothiazine ligand. This ligand can be made in as few as three steps from commercially available starting materials. Presented herein is the synthesis of the ligand along with the synthesis of a chiral molecular receptor that potentially presages a new class of chiral molecular tweezers.

3-Chloro-4-[2-(4-chlorobenzylidene)hydrazinylidene]-1-methyl-3,4-dihydro-1H-2λ6,1-benzothiazine-2,2-dione

“…For background to benzothiazines, see: Misu & Togo (2003); Harmata et al (2006). For the synthesis and biological activity of the title compound and related materials, see: Ahmad et al (2010a); Shafiq et al (2011a).…”

“…Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012); software used to prepare material for publication: SHELXL97. Benzothiazine derivatives are versatile chiral ligands (Harmata et al, 2006) and show various biological activities (Ahmad et al, 2010a, Misu & Togo, 2003. As part of our ongoing studies in this area (Shafiq et al, 2011a,b), we now describe the synthesis and structure of the title compound, (I) (Fig.…”

Synthesis of Novel Anti-Bacterial 2,1-Benzothiazine 2,2-Dioxides Derived From Methyl Anthranilate

“…Besides, characterization of the newly synthesized compounds through spectroscopic techniques and single crystal X-ray analysis, these were also subjected to the preliminary evaluation for their anti-bacterial potential due to their carbohydrazide functionalities 10,11 . e-mail: rehman_pcsir@hotmail.com Figure 1: Examples of some benzothiazine based drugs 2,1-Benzothiazine 2,2-dioxides are now becoming important and are being reported in literature due to their applications in the synthesis of medicinally important natural products and new chiral ligands for catalysis and molecular recognition 7 . Among these, 3,4-dihydro-2,1-benzothiazine 2,2-dioxide derivatives have been reported to possess potent biological activities such as lipoxygenase inhibition and are being used as drugs for treating heart diseases 8 ( Fig.…”

The study of the three-component interaction between 1-ethyl-1H-2,1-benzothiazin-4(3H)-one 2,2-dioxide, heterylcarbaldehydes and active methylene nitriles

“…Specifically, the cyclic sulfonamides (sultams) are important therapeutic and chiral agents [9]. This group includes derivatives of 2,1-benzothiazine (benzosultams), the important class of heterocyclic compounds, due to the fact that derivatives of this heterocyclic system possess the versatile range of biological activities.…”