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Thioesters, thiocarbamates, thiocarbazates, semithiocarbazates, peptides, aza-amino acid conjugates, and azapeptides; and a chemoselective and site-specific functionalization protocol of protected thiocarbazates and semithiocarbazates are described. The protocol features the use of Mitsunobu reaction to alkylate specifically the nitrogen atom close to the acylthiol moiety with alcohols to produce protected mono-substituted thiocarbazates that can be stored for months, activated under mild conditions at low temperature using halonium reagents and integrated orthogonally to make substituted semicarbazides that can be used, e.g., as synthons in synthesis of aza-amino acid conjugates, azapeptides and other peptidomimetics. Methods for preparing and using ureases, carbazides, semicarbazides, beta-peptides, azapeptides, and other peptidomimetics and azapeptide conjugates, and uses of ureases, carbazides, semicarbazides, beta-peptides, azapeptides in drug discovery, diagnosis, inhibition, prevention and treatment of diseases are also described.

The present study describes the discovery and characterization of a series of 5-aryl-2H-tetrazol-3-ylacetamides as G protein-gated inwardly-rectifying potassium (GIRK) channels activators. Working from an initial hit discovered during a high-throughput screening campaign, we identified a tetrazole scaffold that shifts away from the previously reported urea-based scaffolds while remaining effective GIRK1/2 channel activators. In addition, we evaluated the compounds in Tier 1 DMPK assays and have identified a (3-methyl-1H-pyrazol-1-yl)tetrahydrothiophene-1,1-dioxide head group that imparts interesting and unexpected microsomal stability compared to previously-reported pyrazole head groups.

A triazine ring derivatized with morpholine, an N-alkyl-N′-BOC-hydrazine (alkyl=isopropyl or benzyl) and the diethylacetal of glycinylpropionaldehyde undergoes spontaneous dimerization in good yields upon acid-catalyzed deprotection. The resulting 24-member macrocycles can be characterized by NMR spectroscopy, mass spectrometry, and single crystal X-ray diffraction. In the solid state, both homodimers adopt a taco-like conformation. Although each shows π–π stacking between the triazine rings, different patterns of hydrogen bonds emerge. The crystal structure of the isopropyl dimer shows that it includes two molecules of trifluoracetic acid per macrocycle. The trifluoroacetate anion charge balances the protonated triazines, which engage in bifurcated hydrogen bonds with the carbonyl acceptor of the distant glycine. This carbonyl also forms a hydrogen bond with the NH of the proximate glycine. The crystal structure of the benzyl derivative does not include trifluoracetic acid. Instead, two hydrogen bonds form, each between a glycine NH and the lone pair of the C=N nitrogen of the hydrazine group. In the solid state, both molecules present the alkyl side chains and morpholine groups in close proximity. A heterodimer is accessible in approximately statistical yields—along with both homodimers—by mixing the two protected monomers prior to subjecting them to deprotection.

1,2-Diazetidin-3-ones are readily accessible, small ring scaffolds that upon functionalization have the potential to produce diverse 3-dimensional structures for drug discovery. Thus, treatment of diazo hydrazides, obtained from simple hydrazides and malonyl half ester derivatives, followed by diazo transfer, with catalytic amounts of rhodium(II) acetate dimer results in intramolecular carbenoid N?H insertion to give 1,2-diazetidin-3-ones. Although subsequent functionalization reactions could be hampered by the lability of the 4-membered ring, a wide range of new derivatives was available by deprotection at N-1, and subsequent amide or urea formation. The structures of four four-membered rings was confirmed by X-ray crystallography; the compounds showed modest growth inhibitory activity in mammary carcinoma cells.

While the incorporation of one aza-amino acid in peptides has been proved to be beneficial for inducing a structure constraint, increasing the resistance towards proteolysis and improving the biological activity, only very rare examples of the incorporation of two or more consecutive aza-amino acids have been reported. In this work, we demonstrate that this fact is probably due to the unsuspected difficulty in synthesizing such peptide analogues, as illustrated by the synthesis of tripeptide derivatives containing two consecutive aza-amino acids. Herein, we report some general guidelines regarding the activation and the coupling of alkyl-hydrazides either mutually or with a natural amino acid, taking into account their nucleophilicity and the nature of their side chains.

We demonstrate a Au(i)-mediated three-component reaction to DNA-tagged highly substituted 6-oxa-1,2-diazaspiro[4.4]nonanes from either DNA-coupled aldehydes, hydrazides, or alkynols. The choice of the starting material coupled to the DNA tag was critial for the purity of the product as the DNA-aldehyde conjugate yielded the purest products, whereas the alkynol- and hydrazide conjugates returned complex product mixtures. The reaction was compatible with thymine-, cytosine-, and, surprisingly, with adenine-DNA, while guanine-containing DNA strands were degraded under the reaction conditions.

The present invention discloses a kind of as NS4B benzofuran analogue inhibitors, in particular to the formula (I) below or a pharmaceutically acceptable salt thereof. (by machine translation)

An efficient, highly atom economic synthesis of hitherto unknown spirocyclic pyrazolidines in a one-pot process was developed. The gold-catalyzed three-component coupling of alkynols, hydrazines and aldehydes or ketones likely proceeds via cycloisomerization of the alkynol to an exocyclic enol ether and subsequent [3 + 2]-cycloaddition of an azomethine ylide. A library of 29 derivatives with a wide range of functional groups was synthesized in up to 97% yield. With this new method, every position in the final product can be substituted which renders the method ideal for applications in combinatorial or medicinal chemistry.

Emerging yeasts are among the most prevalent causes of systemic infections with high mortality rates and there is an urgent need to develop specific, effective and non-Toxic antifungal agents to respond to this issue. In this study 35 aldehydes, hydrazones and hydrazines were obtained and their antifungal activity was evaluated against Candida species (C. parapsilosis, C.Tropicalis, C. krusei, C. albicans, C. glabrata and C. lusitaneae) and Trichosporon asahii, in an in vitro screening. The minimum inhibitory concentrations (MICs) of the active compounds in the screening was determined against 10 clinical isolates of C. parapsilosis and 10 of T. asahii. The compounds 4-pyridin-2-ylbenzaldehyde] (13a) and tert-butyl-(2Z)-2-(3,4,5-Trihydroxybenzylidine)hydrazine carboxylate (7b) showed the most promising MIC values in the range of 16-32 μg/mL and 8-16 μg/mL, respectively. The compounds' action on the stability of the cell membrane and cell wall was evaluated, which suggested the action of the compounds on the fungal cell membrane. Cell viability of leukocytes and an alkaline comet assay were performed to evaluate the cytotoxicity. Compound 13a was not cytotoxic at the active concentrations. These results support the discovery of promising candidates for the development of new antifungal agents.

Strategies to inhibit kinases by targeting the substrate binding site offer many advantages, including naturally evolved selectivity filters, but normally suffer from poor potency. In this work we propose a strategy to design and prepare covalent substrate-competitive kinase inhibitors as a method to improve potency. We have chosen AKT as the model kinase for this work. Using the AKT-GSK3β cocrystal structure and a reactive cysteine near the substrate binding site, we have identified phenylalanine (Phe) as an appropriate scaffold for the covalent inactivator portion of these inhibitors. By synthesizing compounds that incorporate cysteine-reactive electrophiles into phenylalanine and testing these compounds as AKT inhibitors, we have identified Boc-Phe-vinyl ketone as a submicromolar inactivator of AKT. We also show that Boc-Phe-vinyl ketone (1) potently inhibits AKT1 and inhibits cell growth in HCT116 and H460 cells nearly as well as AKT inhibitors GSK690693 and MK-2206, (2) is selective for kinases that possess an activation loop cysteine such as AKT, (3) requires the vinyl ketone for inactivation, (4) has inactivation that is time-dependent, and (5) alkylates Cys310 of AKT as shown by mass spectrometry. Identification of Boc-Phe-vinyl ketone as a covalent inactivator of AKT will allow the development of peptide and small-molecule substrate-competitive covalent kinase inhibitors that incorporate additional substrate binding elements to increase selectivity and potency. This proof-of-principle study also provides a basis to apply this strategy to other kinases of the AGC and CAMK families.

Behind the mask: Nitrogen-substituted isocyanates are rare and their synthetic potential is virtually untapped. Simple masked precursors can form amphoteric amino isocyanate intermediates in situ, and allows the synthesis of complex hydrazine derivatives upon addition with amines. This reactivity was used in a cascade substitution/hydroamination sequence, and in the assembly of azadipeptide analogues. Copyright

Novel N-(N-Pg-azadipeptidoyl)benzotriazoles 20a-e couple efficiently with α-amino acids 21a-e, dipeptides 22a-c, aminoxyacetic acid 23a, depsidipeptide 23b, and α-hydroxy-β-phenylpropionic acid 27 yielding, respectively, azatripeptides 24a-g, azatetrapeptides 25a,b, a hybrid azatripeptide with an oxyamide bond 26a, a hybrid azatetrapeptide with an ester bond 26b, and a hybrid azatripeptide with an ester bond 28. A new protocol for the synthesis of N-Pg-azatripeptides 33a,b and 35a,b, each containing a natural amino acid at the N-terminus, avoids the low coupling rates of the aza-amino acid residue and enables the solution-phase synthesis of an azaphenylalanine analogue of Leu-enkephalin 40.

An efficient solution-phase synthesis of aza-diketopiperazines (aza-DKP, triazinediones) is reported. A structurally diverse collection of c-[aza-alkylGly-Pro] derivatives and yet unreported 2,4,5-trisubstituted-1,2,4- triazine-3,6-diones has been synthesized starting from Fmoc-l-Pro-OH and various Fmoc-l-amino acids. To extend the practical value of this class of dipeptidomimetics, a general solid-phase synthesis approach amenable to library production was developed on both Wang-PS and HMBA-PS resins. The final acidic treatment of the resins in TFA/water mixture at room temperature enabled the rapid and quantitative cyclization/release highly pure triazinediones. The conformational preferences and the spatial organization of the three substituents of a representative 2,4,5-trisubstituted-1,2,4-triazine-3,6-dione were investigated by X-ray diffraction and 1H NMR spectroscopy.

β-Boc-protected aryl and alkyl hydrazines, useful intermediates for azapeptides and N-substituted pyrazoles, were synthesized by electrophylic amination methodology, using less energetic N-Boc-O-tosyl hydroxylamine as an efficient nitrogen source. Also we have demonstrated a two-step, chromatography-free synthesis of N-Boc-O-tosyl hydroxylamine. Georg Thieme Verlag Stuttgart - New York.

The first kilogram-scale synthesis of the PPARα agonist LY518674 (1) is described. The de novo convergent synthetic approach involved coupling of two rapidly assembled components, triazolone formation via a novel acid-promoted cyclization reaction, and final step saponification, delivering the compound in 32.5% overall yield via eight total steps with a six-step longest linear sequence. A regioselective alkylation on the dianion of 4-hydroxyphenylbutyric acid allowed the direct preparation of one of the convergent coupling partners, carboxylic acid 12, and an unusual solvent effect enabled the installation of a urea group on a protected hydrazine, permitting the regiospecific preparation of the other coupling partner, semicarbazide mesylate 17. Sulfonic acids were found to effect the desired triazolone ring formation, affording 25 from the coupled precursor acyl semicarbazide 23. Following saponification of 25 to 1, a wide solubility differential between ethyl acetate extracts of 1 and solutions of 1 in anhydrous ethyl acetate was harnessed in the final crystallization step to deliver the final compound in high yield and purity. The novel acid-mediated triazolone formation was further evaluated on a range of additional substrates, showing the new methodology to be largely complementary to existing base-mediated triazolone syntheses.

Based on an orthogonal protective group strategy dealing with N-protected hydrazine, we established for the first time a highly efficient synthetic pathway leading to 2,3-benzodiazepine-1,4-dione. Moreover, the versatile reactivities exhibited by this 2,3

(Chemical Equation Presented) Electrophilic amination of primary aliphatic and aromatic amines is reported using a diethylketomalonate-derived oxaziridine to afford the corresponding N-Boc hydrazines in good to excellent yields. The method allows a one-pot synthesis of pyrazoles from primary amines.

We describe the synthesis and activities of a series of pseudopeptides containing an N-aryl-N′-hydroxyalkyl hydrazide core structure to inhibit human immunodeficiency virus protease and viral replication. Of the series, compound Hmb-Leu-N(Bzl)-N(CH2-CH-OH)-rPro-Boc (24) displayed the greatest inhibitory potency (IC50 1 μM) and exhibited enzymatic resistance and stability in vitro.

Azapeptides, peptide analogues in which the α-carbon of one or more of the amino acid residues is replaced with a nitrogen atom, exhibit propensity for adopting β-turn conformations. A general protocol for the synthesis of azapeptides without racemization on solid phase has now been developed by introducing the aza-amino acid residue as an N-Boc-aza1-dipeptide. This approach has been validated by the synthesis of six N-Boc-aza 1-dipeptides and their subsequent introduction into analogues of the C-terminal peptide fragment of the human calcitonin gene-related peptide (hCGRP). By performing an aza-amino acid scan of such antagonist peptides, a set of aza-hCGRP analogues was synthesized to examine the relationship between turn secondary structure and biological activity.

New tool substances may help to unravel the physiological role of the human orphan receptor BRS-3 and its possible use as a drug target for the treatment of obesity and cancer. In continuation of our work on BRS-3, the solid- and solution-phase synthesis of a library of low molecular weight peptidomimetic agonists based on the recently developed short peptide agonist 4 is described. Functional potencies of the compounds were determined measuring calcium mobilization in a fluorometric imaging plate reader (FLIPR) assay. Focusing on the N-terminus, the D-Phe-Gln moiety of 4 was modified in a combinatorial SAR-oriented medicinal chemistry approach. With the incorporation of N-arylated glycine and alanine building blocks azaglycine, piperazine, or piperidine and the synthesis of semicarbazides and semicarbazones, a number of highly potent and selective compounds with a reduced number of peptide bonds were obtained, which also should have enhanced metabolic stability.

An efficient method of synthesis of N-t-butoxycarbonyl-azaamino acid ethyl esters has been described. This method consisted of three stages including: hydrazone formation, its reduction and acylation with ethyl chloroformate. The second step - reduction of the hydrazones to the appropriate hydrazides - was the most challenging. Some reducing agents have been tested, though NaBH3CN was found to lead to the final products with the highest yields in relatively short time and even to allow the selective reduction of C-N bond in the presence of nitro group.

The present invention relates to N-substituted cyclic aza compounds, pharmaceutical compositions comprising such compounds, and methods of their use for effecting neuronal activities.

There are disclosed novel synthetic peptides of the general formula (I) Compounds of formula (I) stimulate the release of growth hormone from the pituitary in humans and animals. A method for increasing the rate and extent of growth of animals to increase their milk and wool production or for the treatment of ailments, and the use of the compounds of formula (I) for the preparation of medicaments, are also disclosed.

The synthesis and identification of a novel series of inhibitors of integrin VLA-4 are described. Their in vitro activity and selectivity against closely related integrins are also presented.

Novel peptide derivatives, compositions containing them, and their use for treating medical disorders resulting from a deficiency in growth hormone are disclosed. The peptides have the formula (I): STR1 wherein a, b, A, R1, L1, D, R3, R4, R2, L2, E and G are as defined in the specification. These peptides exhibit improved resistance to proteolytic degradation, and hence, improved bioavailability.

Molecular modeling and topographic considerations of the thrombin-specific sequences Boc-Asp-Pro-Arg-TS or Ac-d-Phe-Pro-Arg-TS (TS = transition state analog electrophilic center) and related scaffolds led to the design of novel P2-P4-azapeptidomimetic P1-argininal and P1-ketoargininamide derivatives (3a-j). The synthesis and biological activity of these potential serine protease inhibitors are presented.

Two series of symmetry-based HIV protease inhibitors containing (S,S) or (R,R) tartaric acid core structure were prepared and tested for inhibitory property against the enzyme. All compounds showed weak antiprotease activity.

A retroviral protease inhibiting compound of the formula: STR1 is disclosed wherein R 1, R 2, R 5, R 6, Y m and Y' n are herein defined.

A series of potent inhibitors of the HIV-1 protease containing a novel pseudo-symmetric dipeptide isostere 3 was synthesized via ring opening of a protected epoxide with various substituted hydrazines.

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