Thiophenesulfonamides as endothelin receptor antagonists

Primary Sulfonamide Functionalization via Sulfonyl Pyrroles: Seeing the N-Ts Bond in a Different Light

Despite common occurrence in molecules of value, methods for transforming sulfonamides are distinctly lacking. Here we introduce easy-to-access sulfonyl pyrroles as synthetic linchpins for sulfonamide functionalization. The versatility of the sulfonyl pyrrole unit is shown by generating a variety of products through chemical, electrochemical and photochemical pathways. Preliminary results on the direct functionalization of primary sulfonamides are also provided, which may lead to new modes of activation.

Site-selective Suzuki-Miyaura coupling of heteroaryl halides - understanding the trends for pharmaceutically important classes

Suzuki-Miyaura cross-coupling reactions of heteroaryl polyhalides with aryl boronates are surveyed. Drawing on data from literature sources as well as bespoke searches of Pfizer's global chemistry RKB and CAS Scifinder® databases, the factors that determine the site-selectivity of these reactions are discussed with a view to rationalising the trends found.

A simple guide for predicting regioselectivity in the coupling of polyhaloheteroaromatics

A simple guide for predicting the order and site of coupling (Suzuki, Stille, Negishi, Sonogashira, etc.) in polyhaloheteroaromatics based upon the (1)H NMR chemical shift values of the parent non-halogenated heteroaromatics has been developed.

Design, Synthesis, and Biological Activity of Novel, Potent, and Selective (Benzoylaminomethyl)thiophene Sulfonamide Inhibitors of c-Jun-N-Terminal Kinase

Several lines of evidence support the hypothesis that c-Jun N-terminal kinases (JNKs) play a critical role in a wide range of disease states including cell death (apoptosis)-related and inflammatory disorders (epilepsy, brain, heart and renal ischemia, neurodegenerative diseases, multiple sclerosis, rheumatoid arthritis, and inflammatory bowel syndrome). The screening of a compound collection led to the identification of a 2-(benzoylaminomethyl)thiophene sulfonamide (AS004509, compound I) as a potent and selective JNK inhibitor. Chemistry and structure--activity relationship (SAR) studies performed around this novel kinase-inhibiting motif indicated that the left and central parts of the molecule were instrumental to maintaining potency at the enzyme. Accordingly, we investigated the JNK-inhibiting properties of a number of variants of the right-hand moiety of the molecule, which led to the identification of 2-(benzoylaminomethyl)thiophene sulfonamide benzotriazole (AS600292, compound 50a), the first potent and selective JNK inhibitor of this class which demonstrates a protective action against neuronal cell death induced by growth factor and serum deprivation.

Synthesis and anti-tubercular activity of a series of 2-sulfonamido/trifluoromethyl-6-substituted imidazo[2,1-b]-1,3,4-thiadiazole derivatives

A series of 2-sulfonamido/trifluoromethyl-6-(4'-substituted aryl/heteroaryl)imidazo[2,1-b]-1,3,4-thiadiazole derivatives (II) have been synthesized by reaction of 2-amino-5-sulfonamido/trifluoromethyl-1,3,4-thiadiazoles and an appropriate alpha-haloaryl/heteroaryl ketones. Further 5-bromo (III), 5-thiocyanato (IV), 5-gaunylhydrazone (V) derivatives were synthesized in order to study the effect of these substituents on biological activity. Structures of these compounds were established by IR, (1)H NMR, (13)C NMR, Mass and HRMS. The selected compounds were evaluated for their preliminary in vitro anti-tuberculosis activity against Mycobacterium tuberculosis H37Rv strain using radiometric BACTEC and broth dilution assay methods. The results show that compounds 5, 7, 8, 10 and 12 exhibited moderate to good anti-tubercular activity with percentage inhibition of 29, 43, 58, 31 and 41, respectively, at a MIC of >6.25 microg/mL. Compound 18 showed a MIC of 20 microg/mL.

Mass spectrometric investigation of N-sulfonylated purine nucleic bases and nucleosides

The gas/phase behaviour of N-sulfonylated purine nucleic bases and nucleosides towards electron impact (EI) and matrix-assisted laser desorption/ionization (MALDI) occurring in a ion trap of a Fourier transform ion cyclotron resonance mass spectrometer is investigated. The influence of the storage time on the protonated molecule ([M+H](+)) abundance under EI conditions confirms that the formation of these ions proceeds through ion/molecule reactions. Using stored-waveform inverse Fourier transform (SWIFT) selective isolation of M(+.) or H(3)O(+), self-chemical ionization, M(+.)/M, and chemical ionization, H(3)O(+)/M, are detected. Investigation of specific EI expulsion of SO(2), SO(2)H and/or SO(2)H(2) from M(+.) and/or [M+H](+) shows that oxygen protonation in bond;SO(2)bond; proceeds faster than nitrogen protonation. Expulsion of SO(2) from molecular ions is not observed in MALDI mass spectra of nucleosides.

Peptoids as endothelin receptor antagonists

A series of new peptoids as endothelin receptor antagonists has been synthesized. Screening them for their ability to bind with endothelin receptors (ET(A) and ET(B)) competitively in the presence of (125I) endothelin led to the discovery of compounds as possible leads with IC50s in the low micromolar concentrations.

The discovery and structure-activity relationships of nonpeptide, low molecular weight antagonists selective for the endothelin ET(B) receptor

The systematic modification of the ETA selective N-(5-isoxazolyl)benzene-sulfonamide endothelin antagonists to give ETB selective antagonists is reported. The reversal in selectivity was brought about by substitution of the 4-position with aryl and substituted aryl groups. Of all the aromatic substituents studied, the para-tolyl group gave rise to the most active and selective ETB antagonist. Larger substituents caused a decrease in both ETB activity and selectivity. A similar trend was observed by substitution at the 5-position of the N-(5-isoxazolyl)-2-thiophenesulfonamide ETA receptor antagonists. The para-tolyl group was again found to be optimal for the ETB activity and selectivity. The structural features that were found to be favorable for binding to the ETB receptor, that is, the presence of a linear, conjugated pi-system of definite shape and size, have been successfully incorporated into the design of ETB selective polycyclic aromatic sulfonamides antagonists.

Structure-activity relationships of N2-aryl-3-(isoxazolylsulfamoyl)-2-thiophenecarboxamides as selective endothelin receptor-A antagonists

We report here that N2-aryl-3-(isoxazolylsulfamoyl)-2-thiophenecarboxamides are potent and selective small molecule ETA receptor antagonists. The aryl group was subjected to extensive structural modification. With monosubstitution, the para position was most useful in increasing potency, with methyl being preferred. With disubstitution, 2,4-disubstitution further enhanced activity with methyl or cyano groups being preferred at the 2-position. In this series, a benzo-[d][1,3]dioxole group is equivalent to a 4-methyl group in in vitro activity and afforded the compounds with both in vivo activity and moderate half-lives.