Synthesis of 2-quinolinecarboxamide derivatives as potential HDAC inhibitors

Inhibition of histone deacetylase activity appears as an original and effective approach for the treatment of cancer. A series of novel quinoline-containing derivatives has been synthesized and found that some of these compounds possess nanomolar histone deacetylase inhibitory activity.     

Synthesis of novel 3,4-diaryl-5-aminopyrazoles as potential kinase inhibitors

Synthesis of a diverse series of novel 3,4-diaryl-5-aminopyrazoles as candidates in the development of new protein kinase inhibitors is reported for the first time. In the course of a wider study into bisindolylmaleimide (BIM) derivatives, we examined a novel 5-aminopyrazole heterocyclic moiety as a structural analogue of the highly potent VEGF-R2/3 inhibitor pyrrole-2-one (8). The versatile nature of this pharmacophore allows considerable scope for derivatisation and hence exploration of structure activity relationships. Consequently, a variety of structural modifications were used in order to diversify the aminopyrazole ring substituents. Bicyclic derivatives of the parent aminopyrazoles (11, 12) were also synthesised as a means of probing the kinase active site, leading to formation of complex planar pyrimidine moieties. This work provides the framework for new explorations into kinase inhibition and critical investigations into selectivity of inhibitory activity.     

Synthesis and biological evaluation of 3-amino-2-pyrones as selective cyclooxygenase-1 (COX-1) inhibitors

A group of 3-amino-2-pyrones were synthesized and their biological activities were evaluated for inhibiting cyclooxygenase（COX） activity.This study has led to the identification of COX-1-selective inhibitors.Among the tested compounds,the compound 5j exhibited the most potent COX-1 inhibitory activity(IC₅₀ = 19.32μg/mL) and COX-1 selectivity index（SI = 41.98）.     

Synthesis and Crystal Structure of Dimethyl-3-（4-bromophenyl）-1-phenyl-4,5-dihydro-1H-pyrazole-4,5-dicarboxylate

The title compound (C19H17BrN2O4) was synthesized via a one-pot procedure starting from 4-bromobenzaldehyde, dimethyl acetylenedicarboxylate (DMAD) and phenylhydrazine with pyridine as the catalyst. Its structure was determined by single-crystal X-ray diffraction analysis. The crystal belongs to the monoclinic system, space group P21/c with a = 11.115(3), b = 8.090(2), c = 20.211(5) , β = 97.032(5)°, V = 1803.7(8) 3, Z = 4, Mr = 417.25, Dc = 1.536 g/cm3, μ = 2.306 mm-1, F(000) = 852, the final R = 0.0403 and wR = 0.0895 for 2215 observed reflections with I 2σ(I).     

Preparation of 3-arylmethylindoles as selective COX-2 inhibitors

The 3-arylmethylation of indoles using TMSOTf/Et₃SiH with a wide variety of substituted benzaldehydes has been accomplished. Under these mild Lewis acid mediated reductive conditions, it was demonstrated that indoles bearing both 6-MeSO₂ and 2-methyl substituents could be 3-arylmethylated in good to excellent yields to afford the corresponding 3-arylmethyl indoles, effective as selective COX-2 inhibitors. In addition, the viability of this method for the reductive alkylation of indoles by ketones was demonstrated and shown to be C-3 regioselective. For indoles bearing both a 6-MeSO₂ and 2-cyano substituent where this indole reductive alkylation methodology was unsuccessful, an unprecedented Pd(0) mediated arylorganozinc coupling with the requisite substituted 3-methylcarbonatomethylindole proved successful in affording the desired 2-cyano-6-MeSO₂-3-arylmethylindoles effective as selective COX-2 inhibitors.     

Synthesis of 4,5-diaryl-2-(n-methyl-3-carbazolyl)- and 4,5-diaryl-2-(n-methyl-1,2,3,4-tetrahydro-7-carbazolyl) imidazoyl radicals

A number of imidazoles were obtained by the reaction of substituted benzils with aldehydes of the carbazole series. Chlorobenzene solutions of the imidazoles take on a green coloration on oxidation with lead dioxide. The presence of free radicals in these solutions is confirmed by the ESR spectra and by the reaction with hydroquinone, diphenylamine, carbazole, and ,-diphenyl--picrylhydrazine.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1550–1551, November, 1971     

Synthesis of pyrazole derivatives as potential bioisosteres of thromboxane-synthetase inhibitors

A series of ω-carboalkenyl pyrazole derivatives have been synthesized as potential thromboxane-synthetase inhibitors considering the close bioisosteric relationship between the pyrazole ring and other heteroaromatic carboalkenyl compounds exhibiting inhibitory activity. (E)-7-(1-Phenylpyrazol-4-yl)hept-2-enoic acid (4b) were prepared in 28% overall yield from its minor bis-homologue, (E)-5-(1-phenylpyrazol-4-yl)pent-2-enoic acid (4a) , obtained from 4-formyl-1-phenylpyrazole (6) in 17% overall yield. Compounds 4a, 4b, 7, 8 and 13 were screened for their ability to inhibit the in vitro rabbit blood platelet aggregation induced by collagen using the Born test. Among the active compounds 4a exhibited an important inhibition at 1 μM concentration.     

Synthesis of new imidazole derivatives as potential inhibitors of thromboxane synthetase

The preparation of new imidazole derivatives containing a carboxylic moiety such as succinic, adipic or benzoic into the side chain, is reported starting from the suitable imidazole intermediates.     

Synthesis of 2-hydroxy-2-phenylethylamino derivatives as potential α-adrenergic blocking agents

The synthesis of N,N'-bis[6-(2-hydroxy-2-phenylethylamino)hexyl] cystamines 4 , and N-(2-hydroxy-2-phenylethyl)-1,6-hexanediamines 6 are described. Compounds 4 were obtained by condensation of the requisite epoxide 2 with 3-(6-aminohexyl)-1,3-thiazolidine followed by dimerization with opening of the thiazolidine ring. A similar method was used for the preparation of compounds 6. In order to prepare 4j (N,N'-bis{6-[2-hydroxy-2(3,4-dihydroxyphenyl)ethylamino]hexyl}cystamine), several procedures were tested; the method of choice involved the use of 3,4-dihydroxybenzaldehyde with both hydroxy groups protected as methoxymethyl ethers.     

Synthesis of 3-aminorhodanine derivatives as aldose reductase inhibitors

A number of 5-condensated 3-acylaminorhodanines 3 was prepared as potential inhibitors of the aldose reductase by acylation of the amino group of 3-aminorhodanine 1 and subsequent condensation of the 5-methylene function with appropriate aldehydes. Some of these compounds displayed interesting activity.     

Synthesis of 3-(pyridine-2-yl)-4,5-dihydro-1H-pyrazole-1-thiocarboxamides and their copper(II) complexes

New organic ligands 3-(pyridine-2-yl)-4,5-dihydro-1H-pyrazole-1-thiocarboxamides (L) have been synthesized by a two or three step reaction sequence starting from substituted benzaldehydes and 2-acetyl pyridine. Copper(II) complexes with LCuCl₂ composition were obtained by the reactions of these ligands with CuCl₂·2H₂O. The crystal structure of two synthesized complexes has been determined by X-ray analysis. Copper atoms located in a strongly distorted square piramidal environment and coordinated by pyrazoline and pyridine nitrogen atoms, thiocarbamoyl sulfur atom and two chloride-anions. All complexes undergo reversible or quasi-reversible electrochemical reduction at 0.45–0.28 V with the formation of Cu(I) containing intermediates. The cytotoxicity of copper containing complexes, comparable to cisplatin and doxorubicin, was demonstrated using cancer cell lines MCF-7, A549 and HEK293.     

Synthesis of novel flavonoid derivatives as potential HIV‐ Integrase inhibitors

Eighteen novel flavonoid derivatives ‐ substituted chalcones and flavones were synthesized and characterized by using NMR, IR, UV/Vis spectroscopy and elemental analysis. The target compounds were achieved by using a sequence of simple and effective reactions starting from phloroglucinol. The initial hydroxyl groups were protected by methylation and in the final flavones the 5‐OH group was selectively demethylated by means of AlBr₃. 5‐methoxy flavones exhibit a strong fluorescence, which was quenched after the removal of the methyl group.     

Synthesis of galactose-linked uridine derivatives with simple linkers as potential galactosyltransferase inhibitors

Galactose-linked uridine derivatives without charge or dipole contributions in the linker were designed and synthesized via cross metathesis (CM). This strategy would provide a ready access to a range of hybrid compounds linking uridine and galactose derivatives.     

Synthesis of 2-thiobenzimidazole derivatives as potential antifilarial agents

Several 5-benzoyl-2-thiobenzimidazole and 2-thiobenzimidazole aliphatic acids, esters, and N,N-dialkyl-carboxamides and thiocarboxamides were prepared by reacting bromo aliphatic acids, bromo aliphatic esters, and N,N-dialkylcarbamoyl or thiocarbamoyl chlorides with 5-benzoyl-2-thiobenzimidazole or 2-thiobenzimidazole in the presence of base. 2-Thiocarbomethoxy- and 2-thiocarboethoxybenzimidazole were prepared by the reaction of 2-thiobenzimidazole with methyl or ethyl chloroformate in the presence of base. However, the reaction of 5-benzoyl-2-thiobenzimidazole with ethyl chloroformate, afforded 5-benzoyl-2-ethylthiobenz-imidazole.     

Synthesis of Some amino-4,5-dihydropyrazolo[3,4-a]acridines as potential cholinesterase inhibitors

A synthesis of the 4,5-dihydro derivatives of the previously known pyrazolo[3,4-a]acridine ring system is described. The reaction of a 3,4-dihydroacridin-1(2H)-one with N,N-dimethylformamide dimethyl acetal gave a reactive enamino ketone, which yielded the desired heterocycle upon reaction with hydrazine. Using this chemistry, 11-amino-4,5-dihydro-2H-pyrazolo[3,4-a)acridine ( 3 ) and a number of its 2-substituted derivatives 4a-k were synthesized and evaluated as acetylcholinesterase inhibitors, based on their relationship to 1,2,3,4-tetrahydro-9-acridinamine (THA). 1-Amino-4,5-dihydro-1H-pyrazolo[3,4-a]acridine ( 11a ) and 2-amino-4,5-dihydro-1H-pyrazolo[3,4-a]acridine ( 11b ) were also synthesized and investigated as potential cholinesterase inhibitors.