A Convenient Synthesis of 2H-1,2,4-Benzothiadiazine 1,1-Dioxides from 2-Aminobenzenesulfonamide and Carboxylic Acids by using Polyphosphoric Acid Trimethylsilyl Ester as Condensing Agent

Development of subtype-selective covalent ligands for the adenosine A2B receptor by tuning the reactive group

Signalling through the adenosine receptors (ARs), in particular through the adenosine A2B receptor (A2BAR), has been shown to play a role in a variety of pathological conditions, ranging from immune disorders to cancer. Covalent ligands for the A2BAR have the potential to irreversibly block the receptor, as well as inhibit all A2BAR-induced signalling pathways. This will allow a thorough investigation of the pathophysiological role of the receptor. In this study, we synthesized and evaluated a set of potential covalent ligands for the A2BAR. The ligands all contain a core scaffold consisting of a substituted xanthine, varying in type and orientation of electrophilic group (warhead). Here, we find that the right combination of these variables is necessary for a high affinity, irreversible mode of binding and selectivity towards the A2BAR. Altogether, this is the case for sulfonyl fluoride 24 (LUF7982), a covalent ligand that allows for novel ways to interrogate the A2BAR.

Facile Synthesis of 2H-1,2,4-Benzothiadiazine 1,1-Dioxides Promoted by SmI2

2 H-1,2,4-Benzothiadiazine 1,1-dioxides are prepared in good yields via reductive cyclisation of N,N-diethyl- o-nitrobenzenesulfonamides with appropriate nitriles promoted by SmI2 under mild and neutral conditions.

Polyphosphoric Acid Trimethylsilylester: A Useful Reagent for Organic Synthesis

This review describes the composition, preparation and applications in organic synthesis of polyphosphoric acid trimethylsilylester (PPSE). It covers the literature since it first appeared in the eighties until the first trimester of 2007. A discussion of the synthetic utility of PPSE, compared to other related reagents such as polyphosphoric acid (PPA) and polyphosphoric acid ethyl ester (PPE) as well as various Lewis acids, is also included.

Palladium-catalyzed direct C–H arylation of 3-aryl-2H-benzo[1,2,4]thiadiazine 1,1-dioxides: an efficient strategy to the synthesis of benzothiadiazine-1,1-dioxide derivatives

An efficient strategy to the synthesis of 3-aryl-2H-benzo[1,2,4]thiadiazine 1,1-dioxide derivatives via palladium-catalyzed direct arylation of benzothiadiazine-1,1-dioxides with various aryl iodides is described.

Synthetic utility of ammonium salts in a Cu-catalyzed three-component reaction as a facile coupling partner

Ammonium salts were found to be a convenient and inexpensive reagent in the Cu-catalyzed three-component reaction with terminal alkynes and sulfonyl or phosphoryl azides leading to N-unprotected amidines. Thus obtained amidines bearing 2-bromobenzenesulfonyl moiety were efficiently cyclized by the Cu-catalyzed intramolecular N-arylation to give an important pharmacophore skeleton of 2H-1,2,4-benzothiadiazine 1,1-dioxides. Conveniently, two tandem catalytic procedures could be readily operated in one pot.

Synthesis and vasodilator effects of 3- and 7-sulfonylurea-1,2,4-benzothiadiazin-1,1-dioxides on rat aorta

A series of substituted-1,2,4-benzothiadiazin-1,1-dioxide derivatives was designed and synthesized as potassium channel modulators. Various sulfonylurea moieties were introduced on positions 3 and 7 of the heterocycle without, or by means of, methylene and phenyl spacers. On rat aortic rings, several compounds displayed vasodilating activities, especially compound 24, which was more active than cromakalim and diazoxide at low doses (0.1 microM) and more active than diazoxide between 1 and 10 microM.