Metal free oxidative CC bond cleavage: Facile and one-pot tandem synthesis of benzothiadiazine-1,1-dioxides
Graphical abstract
Introduction
Synthesis of heterocyclic compounds is one of the most adorable branch in organic synthesis, due to the significant role of heterocycles in pharmaceuticals, natural products, advanced materials, crop protecting agents [1]. Amongst them benzothidiazine-1,1-dioxides belong to the important class of fused heterocyclic scaffolds because of their diverse biological and pharmacological activities including diuretic [2], antihypertensive [3], anticancer [4], antiviral [5], anti-microbial [6] along with KATP channel activators [7] as well as α1-adrenoceptor antagonists [8].
Copious methodologies have been developed for the preparation of benzothiadiazine-1,1-dioxides by concerning their widespread applications. In last few decades, plenty of methods have been developed for the synthesis of benzothiadiazine-1,1-dioxides. Okano et al. in 1979 reported first for the synthesis of benzothiadiazine-1,1-dioxides using aryl carboxylic acids [9]. The reactions of 2-aminobenzenesulfonamide with carboxylic acid derivatives under harsh conditions are the typical synthetic procedures for the synthesis of benzothiadiazine-1,1-dioxides [10]. Afterwards, various reports were published for the synthesis of benzothiadiazine-1,1-dioxides using aldehydes [11], benzyl alcohols [12] and methylarenes [13]. Another strategy used for the synthesis of 1,2,4-benzothiadiazine-1,1-dioxide involves transition metal catalyzed reactions. An efficient method for the synthesis of benzothiadiazine-1,1-dioxides through iron-catalyzed cascade coupling of 2-bromobenzenesulfonamide with amidine hydrochlorides has been developed by Yang et al. [14]. Whereas, Su and co-workers produced via reductive cyclization of N,N diethyl 2-nitro benzenesulfonamide with nitriles using SmI2 as a reducing agent [15]. Similarly, benzothiadiazine-1,1-dioxides could also be synthesized through condensation of o-halosubstituted benzenesulfonyl chloride with amidines as reported by Cherepakha et al. [16]. K2S2O8-mediated, a transition-metal-free, intramolecular oxidative nitrogenation of C(sp3)-H in N-aryl benzylic amines followed by oxidation has been developed by Laha and co-workers in 2015 [17]. Very recently, Liu et al. have developed palladium-catalyzed oxidative cleavage tandem cyclization reaction of anilines and terminal alkenes for the concise synthesis of various quinazolinone derivatives and benzothiadiazine-1,1-dioxide (Fig. 1(a)) [18].
The transition metal-based protocols, although successful, still have some inherent limitations and environmental toxicity. Considering the advantages of iodine catalyzed oxidation reactions, we decided to continue our research work [19] and here for direct oxidative synthesis of benzothiadiazine-1,1-dioxides from styrene and 2-aminobenzenesulfonamide as a successive protocol (Fig. 1(b)) [20].
Section snippets
Results and discussion
Our previously obtained results for the synthesis of biologically active heterocycles [21], channeled our interest to explore our hypothesis for the synthesis of benzothiadiazine-1,1-dioxides. We began our study with a model reaction of styrene (1a) (1.0 equiv.) 2-aminobenzenesulfonamide (2a) (1.0 equiv.) in tert-butyl hydroperoxide (TBHP) (70% in H2O; 10 equiv.), iodine and various bases (Table 1). Initially, we started optimization of our proposed protocol using styrene (1a) (1.0 equiv.) in
Conclusions
We have demonstrated the general and efficient method for the synthesis of benzothiadiazine-1,1-dioxide via dehomologative oxidation of styrene. A variety of advisable products were obtained in good to moderate yields with high atom economy under environmentally gentle conditions. Notably, this method will facilitate metal and ligand free protocol and one pot formation of biologically salient heterocycles in iodine/TBHP mediated system.
Acknowledgments
B.N.P. and P.A.S. thanks to UGC, New Delhi, India for providing fellowship. A.S.K. and A.C.C. greatly appreciate the generous financial support from the Defence Research and Development Organization (DRDO) (ERIP/ER/1503212/M/01/1666), New Delhi, India.
References (22)
- et al.
Farmaco
(1973) - et al.
J. Comb. Chem.
(2009) - et al.
J. Chem. Res.
(2004) - et al.
Org. Chem. Front.
(2018) - et al.
Domino Reactions in Organic Synthesis
(2006)et al.Curr. Org. Chem.
(2009)et al.Chem. Soc. Rev.
(2007)Chem. Rev.
(1996)et al.Chem. Rev.
(2013)et al.Tetrahedron
(2009)et al.Chem. Soc. Rev.
(2007)et al.Modern Heterocyclic Chemistry
(2011) - et al.
J. Am. Chem. Soc.
(1957)et al.J. Am. Chem. Soc.
(1960) - et al.
Science
(1961)et al.J. Med. Chem.
(1964)et al.J. Med. Chem.
(1972)et al.Bioorg. Med. Chem. Lett.
(2005) - et al.
Bioorg. Med. Chem. Lett.
(2007)et al.Heterocycles
(1993)et al.Curr. Med. Chem.
(2003)et al.Eur. J. Med. Chem.
(2012) - et al.
Curr. Med. Chem.
(2008) - et al.
J. Med. Chem.
(2005)et al.J. Med. Chem.
(2005)et al.ChemMedChem
(2009)
J. Med. Chem.
Bioorg. Med. Chem. Lett.
Cited by (8)
Visible Light-Promoted Fluorescein/Ni-Catalyzed Synthesis of Bis-(β-Dicarbonyls) using Olefins as a Methylene Bridge Synthon
2022, Asian Journal of Organic ChemistryI<inf>2</inf>/TBHP Reagent System: A Modern Paradigm for Organic Transformations**
2022, European Journal of Organic ChemistryIodine-catalyzed tandem oxidative aromatization for the synthesis of meta-substituted alkoxybenzenes
2021, TetrahedronCitation Excerpt :The increasing demands of environmentally benign chemistry have promoted the chemical industries to minimize waste production in organic synthesis [1], [2]. One-pot or tandem reactions can generally provide such an approach because they avoid tedious manipulation processes and thus reduce the produce of wastes in them [3-7]. The construction of substituted alkoxybenzenes has attracted great interests among synthetic chemists because of their widely application in the preparation of high–value pharmaceuticals such as farnesyl protein transferase inhibitors [8], agrochemicals [9], oligomers [10], as well as building blocks in organic synthesis [11].