Bis(heteroaryl)piperazine (BHAP) reverse transcriptase inhibitors: structure-activity relationships of novel substituted indole analogues and the identification of 1-[(5-methanesulfonamido-1H-indol-2-yl)-carbonyl]-4-[3- [(1-methylethyl)amino]-pyridinyl]piperazine monomethanesulfonate (U-90152S), a second-generation clinical candidate

Halogen Bonding in Sulphonamide Co-Crystals: X···π Preferred over X···O/N?

Sulphonamides have been one of the major pharmaceutical compound classes since their introduction in the 1930s. Co-crystallisation of sulphonamides with halogen bonding (XB) might lead to a new class of pharmaceutical-relevant co-crystals. We present the synthesis and structural analysis of seven new co-crystals of simple sulphonamides N-methylbenzenesulphonamide (NMBSA), N-phenylmethanesulphonamide (NPMSA), and N-phenylbenzenesulphonamide (BSA), as well as of an anti-diabetic agent Chlorpropamide (CPA), with the model XB-donors 1,4-diiodotetrafluorobenzene (14DITFB), 1,4-dibromotetrafluorobenzene (14DBTFB), and 1,2-diiodotetrafluorobenzene (12DITFB). In the reported co-crystals, X···O/N bonds do not represent the most common intermolecular interaction. Against our rational design expectations and the results of our statistical CSD analysis, the normally less often present X···π interaction dominates the crystal packing. Furthermore, the general interaction pattern in model sulphonamides and the CPA multicomponent crystals differ, mainly due to strong hydrogen bonds blocking possible interaction sites.

Unified Approach to Benzo[d]thiazol-2-yl-Sulfonamides

In this paper, we report a unified approach to N-substituted and N,N-disubstituted benzothiazole (BT) sulfonamides. Our approach to BT-sulfonamides starts from simple commercially available building blocks (benzo[d]thiazole-2-thiol and primary and secondary amines) that are connected via (a) a S oxidation/S-N coupling approach, (b) a S-N coupling/S-oxidation sequence, or via (c) a S-oxidation/S-F bond formation/SuFEx approach. The labile N-H bond in N-monoalkylated BT-sulfonamides (pK_a (BTSO₂N(H)Bn) = 3.34 ± 0.05) further allowed us to develop a simple weak base-promoted N-alkylation method and a stereoselective microwave-promoted Fukuyama-Mitsunobu reaction. N-Alkyl-N-aryl BT-sulfonamides were accessed with the help of the Chan-Lam coupling reaction. Developed methods were further used in stereo and chemoselective transformations of podophyllotoxin and several amino alcohols.

High Catalytic Activity of Pd Nanoparticles Synthesized from Green Alga Chlorella vulgaris in Buchwald-hartwig Synthesis of N-Aryl Piperazines

Background:

The N-aryl piperazines are an important component of many drug products used for the treatment of malaria, depression, anxiety and Parkinson diseases. Buchwald-Hartwig amination is the latest and well-known reaction for Pd catalyzed direct synthesis of N-aryl piperazine from aryl halides. Although several Pd-ligand systems have already been discovered for this conversion, Pd nanoparticles are recently being used for this useful coupling reaction due to their recyclability and durability. Metal nanoparticles show enhanced catalytic activity compared to their bulk counterparts due to increased surface area at the edges and corners. The use of green algal extract in place of chemical ligands makes this process more environment-friendly and cost-effective. In this research, Pd nanoparticles synthesized using green alga C. Vulgaris were utilized as an alternative approach for the coupling reaction during the preparation of N-aryl piperazines.

Methods:

Synthesized Pd nanoparticles from C. Vulgaris were characterized by FTIR, SEM and XRD techniques. The catalytic activity of the synthesized nanoparticles was monitored for the synthesis of N-aryl piperazines by Buchwald-Hartwig reaction. The synthesized N-aryl piperazines were characterized by NMR, FTIR and mass analysis.

Results:

A very good catalytic activity of the synthesized Pd nanoparticles from green alga Chlorella vulgaris extract was observed. The green alga not only reduces the size of the Pd metal to nanoparticles but also acts as a green ligand for reduction of Pd(II) to Pd(0) during nanoparticle synthesis. Using this Pd nanoparticles-green ligand system, several N-aryl piperazines were synthesized in good to excellent yields. Reaction conditions for better conversion were optimized. The comparative advantage of the catalytic system with recently published works on Buchwald-Hartwig C-N coupling reaction is given. Recyclability and durability of the catalyst were explored and the results were found to be promising. A plausible mechanism of Pd nanoparticle catalyzed reaction is also proposed.

Conclusion:

Catalytic activity of the Pd nanoparticle synthesized from Chlorella vulagris in the synthesis of N-aryl piperazines by Buchwald-Hartwig reaction is reported first time to the best of our knowledge and understanding. The green approach of Pd catalyst to facilitate the reaction and its environmental impact is the main characteristic of the process.

Streamlined Synthesis of Diaminopyridines by Pd-Catalyzed Ammonia Coupling with Deactivated Amino-Chloropyridines

An efficient and cost-effective two-step synthesis of diaminopyridines, fundamental building blocks of biologically active compounds, is reported. The advantages over previously reported routes include cost and wider availability of the bromo-chloropyridine starting materials and the straightforward accessibility to an extended array of diaminopyridine regioisomers. The key enabler of this synthetic strategy is the development of an unprecedented palladium-catalyzed coupling reaction of ammonia with chloropyridines deactivated by the presence of an alkylamino substituent. The coupling reaction was accomplished with very low catalyst loadings under remarkably mild reaction conditions, making the system particularly suitable for both academic and industrial applications. The utility of this methodology is exemplified by the application to the synthesis of highly relevant scaffolds, including the synthetic intermediates of the marketed drugs Ribociclib and Palbociclib.

Synthesis of New Quinazoline-2,4(1H,3H)-dione non-nucleoside Analogues of the reverse transcriptase inhibitor TNK-651

The synthesis is described of a series of new non-nucleoside analogues of the reverse transcriptase inhibitor TNK-651 from quinazoline-2,4(1 H,3 H)-diones. Compounds 2a–c were silylated and treated with benzyl chloromethyl ether in the presence of CsI to give 1-benzyloxymethylquinazoline derivatives 3a–c. Treatment of the silylated quinazolinediones 2a–c with the appropriate acetals 5a–e in the presence of TMS triflate afforded the corresponding TNK-651 analogues 6–10.

The Journey of HIV-1 Non-Nucleoside Reverse Transcriptase Inhibitors (NNRTIs) from Lab to Clinic

Human immunodeficiency virus (HIV) infection is now pandemic. Targeting HIV-1 reverse transcriptase (HIV-1 RT) has been considered as one of the most successful targets for the development of anti-HIV treatment. Among the HIV-1 RT inhibitors, non-nucleoside reverse transcriptase inhibitors (NNRTIs) have gained a definitive place due to their unique antiviral potency, high specificity, and low toxicity in antiretroviral combination therapies used to treat HIV. Until now, >50 structurally diverse classes of compounds have been reported as NNRTIs. Among them, six NNRTIs were approved for HIV-1 treatment, namely, nevirapine (NVP), delavirdine (DLV), efavirenz (EFV), etravirine (ETR), rilpivirine (RPV), and doravirine (DOR). In this perspective, we focus on the six NNRTIs and lessons learned from their journey through development to clinical studies. It demonstrates the obligatory need of understanding the physicochemical and biological principles (lead optimization), resistance mutations, synthesis, and clinical requirements for drugs.

Biological evaluation and structure activity relationship of 9-methyl-1-phenyl-9H-pyrido[3,4-b]indole derivatives as anti-leishmanial agents

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New anti-leishmanial agents designed through molecular hybridization approach.

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7d showed potent anti-leishmanial activity against both L. infantum & L. donovani.

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7d EC₅₀ against L. infantum promastigotes, axenic amastigotes 1.59 & 1.4 µM.

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7d EC₅₀ against L. donovani promastigotes, axenic & intracellular amastigotes 0.91 & 0.91 & 1.4 µM.

A series of piperazinyl-β-carboline-3-carboxamide derivatives were designed through a molecular hybridization approach. Designed analogues were synthesized, characterized and evaluated for anti-leishmanial activity against Leishmania infantum and Leishmania donovani. In L. infantum inhibition assay, compounds 7d, 7g and 7c displayed potent inhibition of promastigotes (EC₅₀ 1.59, 1.47 and 3.73 µM respectively) and amastigotes (EC₅₀ 1.4, 1.9 and 2.6 µM respectively). SAR studies revealed that, para substitution of methoxy, chloro groups and methyl group on ortho position favored anti-leishmanial activity against L. infantum. Among these analogues 7d, 7h, 7n and 7g exhibited potent inhibition against L. donovani promastigotes (EC₅₀ 0.91, 4.0, 4.57 and 5.02 µM respectively), axenic amastigotes (EC₅₀ 0.9, 3.5, 2.2 and 3.8 µM respectively) and intracellular amastigotes (EC₅₀ 1.3, 7.8, 5.6 and 6.3 µM respectively). SAR studies suggested that, para substitution of methoxy group, para and meta substitution of chloro groups and benzyl replacement recommended for significant anti-leishmanial against L. donovani.

Advances in diarylpyrimidines and related analogues as HIV-1 nonnucleoside reverse transcriptase inhibitors

HIV-1 nonnucleoside reverse transcriptase inhibitors (NNRTIs) have been playing an important role in the fight against acquired immunodeficiency syndrome (AIDS). Diarylpyrimidines (DAPYs) as the second generation NNRTIs, represented by etravirine (TMC125) and rilpivirine (TMC278), have attracted extensive attention due to their extraordinary potency, high specificity and low toxicity. However, the rapid emergence of drug-resistant virus strains and dissatisfactory pharmacokinetics of DAPYs present new challenges. In the past two decades, an increasing number of novel DAPY derivatives have emerged, which significantly enriched the structure-activity relationship of DAPYs. Studies of crystallography and molecular modeling have afforded a lot of useful information on structural requirements of NNRTIs, which contributes greatly to the improvement of their resistance profiles. In this review, we reviewed the discovery history and their evolution of DAPYs including their structural modification, derivatization and scaffold hopping in continuous pursuit of excellent anti-HIV drugs. And also, we discussed the prospect of DAPYs and the directions of future efforts.

Synthesis and in-vitro anti-leishmanial activity of (4-arylpiperazin-1-yl)(1-(thiophen-2-yl)-9H-pyrido[3,4-b]indol-3-yl)methanone derivatives

In the present study, we have reported synthesis and biological evaluation of a series of fifteen 1-(thiophen-2-yl)-9H-pyrido[3,4-b]indole derivatives against both promastigotes and amastigotes of Leishmania parasites responsible for visceral (L. donovani) and cutaneous (L. amazonensis) leishmaniasis. Among these reported analogues, compounds 7b, 7c, 7f, 7g, 7i, 7j, 7m, 7o displayed potent activity (15.55, 7.70, 7.00, 3.80, 14.10, 9.25, 3.10, 4.85μM, respectively) against L. donovani promastigotes than standard drugs miltefosine (15.70μM) and pentamidine (32.70μM) with good selectivity index. In further, in-vitro evaluation against amastigote forms, two compounds 7g (8.80μM) and 7i (7.50μM) showed significant inhibition of L. donovani amastigotes. Standard drug amphotericin B is also used as control to compare inhibition potency of compounds against both promastigote (0.24μM) and amastigote (0.05μM) forms.

Design, synthesis and anti-HIV-1 RT evaluation of 2-(benzyl(4-chlorophenyl)amino)-1-(piperazin-1-yl)ethanone derivatives

In this study, using molecular hybridization approach, fourteen novel 2-(benzyl(4-chlorophenyl)amino)-1-(piperazin-1-yl)ethanone derivatives (7a-n) were designed as inhibitor of HIV-1 RT. The binding affinity of the designed compounds with HIV-1 RT as well as their drug-likeness behavior was predicted using in-silico studies. All the designed compounds were synthesized, characterized and in-vitro evaluated for HIV-1 RT inhibitory activity, in which tested compounds displayed significant to weak potency against the selected target. Moreover, best active compounds of the series, 7k and 7m inhibited the activity of RT with IC₅₀ values 14.18 and 12.26μM respectively. Structure Activity Relationship (SAR) studies were also performed in order to predict the influence of substitution pattern on the RT inhibitory potency. Anti-HIV-1 and cytotoxicity studies of best five RT inhibitor (7a, 7d, 7k, 7L and 7m) revealed that, except compound 7d other compounds retained significant anti-HIV-1 potency with good safety index. Best scoring pose of compound 7m was analysed in order to predict its putative binding mode with wild HIV-1 RT.

Pd-Catalyzed Synthesis of Piperazine Scaffolds Under Aerobic and Solvent-Free Conditions

A facile Pd-catalyzed methodology providing an efficient synthetic route to biologically relevant arylpiperazines under aerobic conditions is reported. Electron donating and sterically hindered aryl chlorides were aminated to afford yields up to 97%, with examples using piperazine as solvent, illustrating an ecofriendly, cost-effective synthesis of these privileged structures.

An accelerated background subtraction algorithm for processing high-resolution MS data and its application to metabolite identification

Background: Metabolite identification without radiolabeled compound is often challenging because of interference of matrix-related components. Results: A novel and an effective background subtraction algorithm (A-BgS) has been developed to process high-resolution mass spectral data that can selectively remove matrix-related components. The use of a graphics processing unit with a multicore central processing unit enhanced processing speed several 1000-fold compared with a single central processing unit. A-BgS algorithm effectively removes background peaks from the mass spectra of biological matrices as demonstrated by the identification of metabolites of delavirdine and metoclopramide. Conclusion: The A-BgS algorithm is fast, user friendly and provides reliable removal of matrix-related ions from biological samples, and thus can be very helpful in detection and identification of in vivo and in vitro metabolites.

Design, Synthesis and Antiviral Activity of New Pyridinone Derivatives

A molecular modelling study was carried out in order to compare the structural and electronic properties of the pyridinone L-696,229 and the HEPT derivative EBPU. This comparison led to a hybrid structure, 3-(benzyloxymethyl)-5-ethyl-6-methylpyridin-2-one [18a], which revealed a good structural correlation with the models. A series of 2-[(arylmethyl)oxymethyl]pyridin-2-ones related to [18a] was synthesized and tested for antiviral activity against human immunodeficiency virus type 1 (HIV-1). Compound [18a] and four other derivatives showed anti-HIV-1 activity.

Design, synthesis and evaluation of diarylpiperazine derivatives as potent anti-tubercular agents

Molecular hybridization is an emerging approach to design novel ligands by combination of two or more pharmacophoric subunits of known bioactive compounds. In the present study, we have designed a novel series of diarylpiperazine analogues, synthesized, characterized using FTIR, (1)H NMR, Mass, Elemental analysis and evaluated their in-vitro anti-tubercular activity. Among the reported sixteen diarylpiperazines, eleven analogues exhibited significant anti-tubercular activity against Mycobacterium tuberculosis H37Rv strain with MIC values below 6.25 μg/mL and good selectivity index. Structure activity relationship studies concluded that, ortho-para directing group (except para chloro) substitution on ortho and para position of piperazine attached phenyl ring favored anti-tubercular activity.

Vibrational spectroscopic and computational study of 1,7,8,9-Tetrachloro-4-(4-bromo-butyl)-10,10-dimethoxy-4-aza-tricyclo[5.2.1.0(2,6)] dec-8-ene-3,5-dione

The optimized molecular structure, vibrational frequencies, corresponding vibrational assignments of 1,7,8,9-Tetrachloro-4-(4-bromo-butyl)-10,10-dimethoxy-4-aza-tricyclo[5.2.1.0(2,6)] dec-8-ene-3,5-dione (TDAD) have been investigated experimentally and theoretically using Gaussian09 software package. Potential energy distribution of normal modes of vibrations was done using GAR2PED program. Gauge-including atomic orbital (1)H NMR chemical shifts calculations were carried out and compared with experimental data. The HOMO and LUMO analysis is used to determine the charge transfer within the molecule. The stability of the molecule arising from hyper-conjugative interaction and charge delocalization has been analyzed using NBO analysis. Molecular Electrostatic Potential was performed by the DFT method and infrared intensities and Raman activities are also reported. Mulliken's net charges have been calculated and compared with the atomic natural charges. First hyperpolarizability is calculated in order to find its role in non-liner optics. The calculated geometrical parameters are in agreement with that of similar derivatives.

The nucleoside reverse transcriptase inhibitors, nonnucleoside reverse transcriptase inhibitors, and protease inhibitors in the treatment of HIV infections (AIDS)

The majority of the drugs currently used for the treatment of HIV infections (AIDS) belong to either of the following three classes: nucleoside reverse transcriptase inhibitors (NRTIs), nonnucleoside reverse transcriptase inhibitors (NNRTIs), and protease inhibitors (PIs). At present, there are 7 NRTIs, 5 NNRTIs, and 10 PIs approved for clinical use. They are discussed from the following viewpoints: (i) chemical formulae; (ii) mechanism of action; (iii) drug combinations; (iv) clinical aspects; (v) preexposure prophylaxis; (vi) prevention of mother-to-child transmission; (vii) their use in children; (viii) toxicity; (ix) adherence (compliance); (x) resistance; (xi) new NRTIs, NNRTIs, or PIs in (pre)clinical development; and (xii) the prospects for a "cure" of the disease.

Study on the structure and vibrational spectra of efavirenz conformers using DFT: comparison to experimental data

Efavirenz, (S)-6-chloro-4-(cyclopropylethynyl)-1,4-dihydro-4-(trifluoromethyl)-2H-3,1-benzoxazin-2-one, is an anti HIV agent belonging to the class of the non-nucleoside inhibitors of the HIV-1 virus reverse transcriptase. A systematic quantum chemical study of the possible conformations, their relative stabilities and vibrational spectra of efavirenz has been reported. Structural and spectral characteristics of efavirenz have been studied by vibrational spectroscopy and quantum chemical methods. Density functional theory (DFT) calculations for potential energy curve, optimized geometries and vibrational spectra have been carried out using 6-311++G(d,p) basis sets and B3LYP functionals. Based on these results, we have discussed the correlation between the vibrational modes and the crystalline structure of the most stable form of efavirenz. A complete analysis of the experimental infrared and Raman spectra has been reported on the basis of wavenumber of the vibrational bands and potential energy distribution. The infrared and the Raman spectra of the molecule based on DFT calculations show reasonable agreement with the experimental results. The calculated HOMO and LUMO energies shows that charge transfer occur within the molecule.

Spectroscopic investigations and computational study of 4-(3-bromopropyl)-4-azatricyclo [5.2.2.0(2,6)]undecane-3,5,8-trione

Fourier-transform (FT)-Raman and FT-infrared spectrum of 4-(3-bromopropyl)-4-azatricyclo [5.2.2.0(2,6)]undecane-3,5,8-trione were recorded and analyzed. The vibrational wavenumbers were examined theoretically using the Gaussian03 set of quantum chemistry codes, and the normal modes were assigned by potential energy distribution (PED) calculations. The first hyperpolarizability, predicted infrared intensities and Raman activities are reported. The calculated first hyperpolarizability is comparable with reported values of similar structures which makes this compound an attractive object for future studies of nonlinear optics. The calculated first hyperpolarizability was found to be very high and it is due to the pi-electron cloud movement from donor to acceptor which makes the molecule highly polarized and the intermolecular charge transfer interaction which is justified by the FT-IR spectrum due to the presence of strong broad bands in the region 2873-2000cm(-1). Optimized geometrical parameters of the compound are in agreement with similar reported structures.

Looking for an active conformation of the future HIV type-1 non-nucleoside reverse transcriptase inhibitors

HIV type-1 (HIV-1) non-nucleoside reverse transcriptase inhibitors (NNRTIs) are key drugs of highly active antiretroviral therapy (HAART) in the clinical management of AIDS/HIV infection. NNRTI-based HAART regimes effectively suppress viral reproduction, are not cytotoxic and show favourable pharmacokinetic properties. First-generation NNRTIs suffer the rapid selection of viral variants, hampering the binding of inhibitors into the reverse transcriptase (RT) non-nucleoside binding site (NNBS). Efforts to improve these first inhibitors led to the discovery of second-generation NNRTIs that proved to be effective against the drug-resistant mutant HIV-1 strains. The success of such agents launched a new season of NNRTI design and synthesis. This paper reviews the characteristics of second-generation NNRTIs, including etravirine, rilpivirine, RDEA-806, UK-453061, BIRL 355 BS, IDX 899, MK-4965 and HBY 097. In particular, the binding modes of these inhibitors into the NNBS of the HIV-1 RT and the most clinically relevant mutant RTs are analysed and discussed.

Quantum chemical DFT study of 4-azatricyclo [5.2.2.0(2,6)] undecane-3,5,8-trione

Fourier-transform-Raman and infrared spectrum of 4-azatricyclo [5.2.2.0(2,6)] undecane-3,5,8-trione were recorded and analyzed. The vibrational wavenumbers were examined theoretically using the Gaussian03 set of quantum chemistry codes, and the normal modes were assigned by potential energy distribution (PED) calculations. The first hyperpolarizability, predicted infrared intensities and Raman activities are reported. The calculated first hyperpolarizability is comparable with reported values of similar structures which makes this compound an attractive object for future studies of nonlinear optics. Optimized geometrical parameters of the compound are in agreement with similar reported structures. The red shift of the NH stretching wavenumber in the infrared spectrum from the computational wavenumber indicates the weakening of NH bond.

Synthesis and evaluation of in vitro biological activity of 4-substituted arylpiperazine derivatives of 1,7,8,9-tetrachloro-10,10-dimethoxy-4-azatricyclo[5.2.1.0(2,6)]dec-8-ene-3,5-dione

A series of twenty arylpiperazine derivatives of 1,7,8,9-tetrachloro-10,10-dimethoxy-4-azatricyclo[5.2.1.0^2,6]dec-8-ene-3,5-dione have been prepared. These derivatives were tested in vitro with the aim of identifying novel lead compounds active against emergent and re-emergent human and cattle infectious diseases (AIDS, hepatitis B and C, tuberculosis, bovine viral diarrhea). In particular, these compounds were evaluated in vitro against representatives of different virus classes, such as a HIV-1 (Retrovirus), a HBV (Hepadnavirus) and the single-stranded RNA⁺ viruses Yellow fever virus (YFV) and Bovine viral diarrhea virus (BVDV), both belonging to the Flaviridae. Compounds 2c, 2g and 3d showed a modest activity against CVB-2. The molecular structures of the starting imide 1 and one of propyl-piperazine derivatives, 3b, have been determined by an X-ray crystallography study.

4-Azatricyclo[5.2.2.02,6]undecane-3,5,8-triones as potential pharmacological agents

A series of twenty six arylpiperazine and aminoalkanol derivatives of 4-aza-tricyclo[5.2.2.0^2,6]undecane-3,5,8-trione have been prepared. The synthesized compounds were evaluated for their cytotoxicity and anti-HIV-1 activity in MT-4 cells.

Chemical transformation and biological studies of marine sesquiterpene (S)-(+)-curcuphenol and its analogs

Chemical transformation studies of the marine sesquiterpene phenol (S)-(+)-curcuphenol (1), isolated from the Jamaican sponges Myrmekioderma styx, were accomplished. In order to optimize the activity and better understand the SAR of (S)-(+)-curcuphenol, nineteen semisynthetic analogs were prepared and evaluated for activity against infectious diseases. A number of analogs showed significant activity against Mtb and Leishmania donovani, while showed good to moderate activities in antibacterial and antifungal assays as well as against Plasmodium falciparium (D6 clone) and (W2 clone). The analogs a, c, h, and r exhibited Mtb activity with MICs of 24.6, 41.2, 6.90, and 50.5 microM, respectively. Analog f showed enhanced activity against L. donovani with an IC50 of 0.6 microM and IC90 of 40 microM respectively.

Facile N-arylation of amines and sulfonamides and o-arylation of phenols and arenecarboxylic acids

An efficient, transition-metal-free procedure for the N-arylation of amines, sulfonamides, and carbamates and O-arylation of phenols and carboxylic acids has been achieved by allowing these substrates to react with a variety of o-silylaryl triflates in the presence of CsF. Good to excellent yields of arylated products are obtained under very mild reaction conditions. This chemistry readily tolerates a variety of functional groups.

Synthesis of benzenepropanamine analogues as non-detergent spermicides with antitrichomonas and anticandida activities

Fifteen analogues of benzenepropanamine were synthesized and evaluated for their spermicidal as well as microbicidal activities against Trichomonas vaginalis and Candida spp. Several compounds showed appreciable dual activities. Compound 12 exhibited good spermicidal (MEC=0.1%) along with substantial anticandidal (MIC=0.05%) activities, while compounds 3 and 6 showed significant microbicidal activities with moderate spermicidal effect. The SAR of these structures is being discussed here in this communication. It is concluded that suitable structural modifications in this class of compounds at 3-amino position may lead to a potent spermicide with associated microbicidal activity.

Synthesis and catalysed hydroboration of styryl sulfonamides

We have prepared the aryl sulfonamides 4,4′-R-C6H4SO2NHC6H4CH=CH2 (R = CH3, 1a; NO2, 1b) by addition of 2 equiv. of 4-vinylaniline to the corresponding sulfonyl chlorides. The disulfonamides 4,4,4′-(R-C6H4SO2)2NC6H4CH=CH2 (R = CH3, 2a; NO2, 2b) were also prepared using 4-vinylaniline and 2 equiv. of the sulfonyl chlorides in the presence of DMAP. Although hydroborations of sulfanilamide derivatives 1 suffered from competing hydrogenation reactions, judicious choice of the transition metal catalyst gave selective formation of either the primary or secondary boronate esters in hydroborations of 2a.Key words: boronate esters, catalysed hydroborations, sulfanilamides, vinylaniline.

A novel HIV-1 antiviral high throughput screening approach for the discovery of HIV-1 inhibitors

Antiviral high throughput screens remain a viable option for identifying novel target inhibitors. However, few antiviral screens have been reduced to practice on an industrial scale. In this study, we describe an HIV-1 dual reporter assay that allows for the simultaneous evaluation of the potential antiviral activities and cytotoxicities of compounds in a high throughput screen (HTS) format. We validate the assay with known HIV-1 inhibitors and show that the antiviral and cytotoxic activities of compounds are reproducibly measured under screening conditions. In addition, we show that the assay exhibits parameters (e.g., signal-to-background ratios and Z' coefficients) suitable for high throughout screening. In a pilot screen, we demonstrate that non-specific or cytotoxic compounds represent a significant fraction of the hits identified in an antiviral screen and that these false positives are identified and deprioritized by the HIV-1 dual reporter assay at the primary screening step. We propose that the HIV-1 dual reporter assay represents a novel approach to HIV-1 antiviral screening that allows for the effective execution of industrial scale HTS campaigns with significantly greater returns on resource investment when compared to previous methods.