Reactions with hydroxamoyl halides: Synthesis of several isoxazole,imidazo[1,2-a]pyridine,imidazo[1,2-a]pyrimidine and benz-1,2,4-triazine derivatives

Benzofuroylhydroxamoyl chloride ( 3 ) reacted with acrylonitrile, N-tolyl-maleimide and active methylene compounds to afford the isoxazoline 4 , the pyrrolidino[3,4-d]isoxazoline 5 and the isoxazole derivatives 6,7 , respectively. Nitrosoimidazo[1,2-a]pyridines 10 and the imidazo[1,2-a]pyrimidine 12 were obtained by the reaction of 3 with 2-aminopyridine and 2-aminopyrimidine, respectively. 3 reacted also with o-phenylenediamine and o-aminothiophenol to give the dihydrobenztriazine 13 and the benzothiadiazine 15 , respectively.     

Anti‐anxiety and sedative profile evaluation of imidazo[1,2‐a]pyridine derivatives

Three imidazo[1,2‐a]pyridine‐3‐nitrosated (L‐1, L‐2, L‐3) and a 3‐formyl imidazo[1,2‐a]pyridine thiosemicarbazone (L‐4) were synthesized and evaluated for their effects in the elevated plus maze, burying behavior test, rotarod performance, the horizontal wire test, and locomotor activity. L‐2 and L‐3 increased the percent time spent in the open arms of the plus maze at doses of 1 and 2 mg/kg without modifying the number of total entries. In addition, L‐2 and L‐3 (1 mg/kg) increased the number of open arm entries indicating anxiolytic‐like activity at this dose. In the burying behavioral test, L‐1 (2–8 mg/kg), L‐2 (8 mg/kg), and L‐3 (4 and 8 mg/kg), induced a clear reduction in cumulative burying behavior, without modifying burying behavior latency, thus reducing experimental anxiety. In the rotarod test, L‐1 and L‐2 impaired rotarod performance only at the highest evaluated dose (64 mg/kg) at which reduction of motor activity was observed and thereby no conclusions about myorelaxant effects can be proposed. All compounds showed a clear sedative effect and corresponding ED₅₀ values were obtained. Results indicate that compounds L‐1, L‐2, and L‐3 show a sedative and an anxiolytic profile. Drug Dev Res 71:371–381, 2010. © 2010 Wiley‐Liss, Inc.     

2-芳基咪唑并[1,2-a]吡啶-3-乙酰胺衍生物的合成与抗焦虑活性研究

目的寻找水溶性较好、抗焦虑活性较强的新型化合物。方法设计合成2-芳基咪唑并[1,2-a]吡啶-3-乙酰胺类化合物,通过体外苯二氮受体竞争结合实验及小鼠高架迷宫行为实验,评价化合物的体内外抗焦虑活性,分析化合物的构效关系。结果与结论共合成28个新型化合物,通过1H-NMR和MS确证其结构,其中I8和I10水溶性良好。苯二氮受体竞争结合实验结果表明,化合物Ⅰ1、Ⅰ8、Ⅰ10、Ⅰ13、Ⅰ19与苯二氮受体的亲和力与阳性对照药物Ro5-4864相当,在浓度为100nmol/L时,其对放射性配体与受体结合的抑制率分别为87%、89%、85%、89%和76%,而Ro5-4864为82%。对水溶性及活性均较好的化合物Ⅰ和Ⅰ进行小鼠抗焦虑活性评价结果表明,其具有明显的体内抗焦虑作用。     

Novel synthesis of imidazo[1,2-b]pyrazoles and their fused derivatives

4-Arylazo-1H-pyrazol-3,5-diamines1a-c reacted with bromomalononitrile (2) to yield the corresponding imidazo[1,2-b]pyrazoles3a-c. The latter reacted with some active methylene compounds and with α-cinnamonitriles to afford the corresponding pyrazoloimidazopyridines6, 8, 9 and15, respectively. Compounds3 reacted with each of formic acid, formamide, trichloroacetonitrile and with guanidine to yield the corresponding pyrazoloimidazopyrimidines16–19, respectively.     

Synthesis of novel 4,5-dihydropyrrolo[1,2-a]quinoxalines,pyrrolo[1,2-a]quinoxalin]-2-ones and their antituberculosis and anticancer activity

A facile strategy was developed for the synthesis of biologically important 4,5-dihydropyrrolo[1,2-a]quinoxalines and pyrrolo[1,2-a]quinoxalin]-2-ones by treating 2-(1H-pyrrol-1-yl)anilines with imidazo[1,2-a]pyridine-3-carbaldehyde or isatin, using amidosulfonic acid (NH₃SO₃) as a solid catalyst in water at room temperature. The protocol has been extended to electrophile ninhydrin. The catalyst could be recycled for six times without the loss of activity. The compounds were evaluated for their antituberculosis, antibacterial, and anticancer activities. It is worth noting that compounds 3d and 3e demonstrated a minimum inhibitory concentration value of 6.25 µM against Mycobacterium tuberculosis H37Rv, whereas compounds 3d , 3g , 5d , 5e , and 5i showed a remarkable inhibition of A549, DU145, HeLa, HepG2, MCF-7, and B16-F10 cell lines, respectively. Staphylococcus aureus was inhibited by compounds 5b , 5e , 5d , 5g , and 5l at 32 µg/ml.     

2-Phenylimidazo[1,2-a]pyridine-3-carboxylic Acid Derivatives: Synthesis and Antiinflammatory Activity

A series of 2-phenylimidazo[1,2-a]pyridine-3-carboxylic esters, acids, and amides were synthesized and pharmacologically tested in order to evaluate their antiinflammatory and analgesic activity and their ulcerogenic action on the gastro-intestinal tract. The most active member of this series of compounds was found to be 6-methyl-2-phenylimidazo[1,2-a]pyridine-3-carboxylic acid ( 5c ).     

Synthesis and biological evaluation of new imidazo[1,2-a]pyridine derivatives designed as mefloquine analogues

This paper describes the synthesis and the in vitro antimalarial profile of two new imidazo[1,2-a]pyridine derivatives 4HCl and 13HCl, structurally proposed as mefloquine (1) analogues, by exploring bioisosterism and molecular simplification tools. The synthetic route employed to access the title compounds used, as starting material, the previously described ethyl 2-methylimidazo[1,2-aJpyridine-3-carboxylate derivative (5). These novel heterocyclic derivatives 4HCl and 13HCl presented modest antimalarial activity against the W-2 and D-6 clones of Plasmodium falciparum as well as inhibitors of in vitro heme polymerization compared to mefloquine.     

Reactions with 3-amino-1,2,4-triazole: Synthesis of several new 1,2,4-triazolo[5,1-a]pyrimidine derivatives

Several new 1,2,4-triazolo[5,1-a]pyrimidine derivatives were synthesized via the reactions of 3-amino-1,2,4-triazole with active methylene nitriles and thier ylidene derivatives. The structures assigned for the reaction products were based on elemental analyses and spectral data.     

Benzimidazole condensed ring systems: New synthesis and antineoplastic activity of substituted 3,4-dihydro- and 1,2,3,4-tetrahydro-benzo [4,5]imidazo[1,2-a]pyrinnidine derivatives

As part of an ongoing effort to develop new antineoplastic agents, a series of substituted 3,4-dihydro- and 1,2,3,4-tetrahydro-benzo[4,5]imidazo[1,2-a]pyrimidine derivatives (5-19) were synthesized. 1,2,3,4-Tetrahydrobenzo[4,5]imidazo[1,2-a]pyrimidine-2-one derivatives (5-7) were prepared via one-pot two-component thermal cyclization reaction of 2-aminobenzimidazole 1 and P-substituted methyl cinnamates (2-4). Vilsmir-Haack formylation of these derivatives (5-7) afforded the 2-chloro-3-carboxaldehyde targets (8-10) followed by nucleophilic displacement of the chloro atom in the 3-carboxaldehyde compounds (8-10) to yield the remaining final targets (11-19). The structures of the synthesized derivatives (5-19) were confirmed by means of IR, 1H NMR, MS and elemental analyses. The synthesized derivatives (5-19) were subjected to the National Cancer Institute (NCI) in vitro disease human cell screening panel assay. 2-Chloro-4-phenyl-3,4-dihydrobenzo[4,5]imidazo[1,2-a]pyrimidine-3-carboxyaldehyde (8, NCI 722731) and 4-(4-methoxyphenyl)-2-(4-methylpiperazin-1-yl)-3,4-dihydrobenzo[4,5]imidazo [1,2-a]pyrimidine-3-carboxaldehyde (18, NCI 722739) showed a variable degree of antineoplastic activity against some of the cell lines tested. 2-Chloro-4-(4-nitrophenyl)-3,4-dihydrobenzo[4,5]imidazo[1,2-a]pyrimidine-3-carboxyaldehyde (10, NCI 722743) exhibited good in vitro antineoplastic activity with subpanel disease selectivity against all the cell lines tested with log10 G150 (M), the concentration that inhibits 50% of cell growth, values ranging from -5.08 to < -8.00.     

Synthesis and cytotoxic activity of imidazo[1,2-a]-1,3,5-triazine analogues of 6-mercaptopurine

A series of 2-substituted imidazo[1,2-a]-1,3,5-triazines with various aliphatic and aromatic amines has been prepared and characterized by IR,1H-NMR, and elemental analysis. The initial in-vitro cytotoxicity studies with five human cancer cell lines showed that all but one of the compounds are without cytotoxic activity. The one active compound, 2-(indolin-1-yl)-7,8-dihydroimidazo[1,2-a]-1,3,5-triazine-4(6H)-thione 12, was tested on 12 human cancer cell lines. Of these, two lines, RT-4 and MCF-7, were the most sensitive to the compound, with IC50 values of 6.98 microM and 8.43 microM, respectively. When compared with the reference anticancer drug 6-mercaptopurine, only the RT-4 urinary bladder and KYSE-70 oesophagus cancer cell lines were more sensitive to the new compound. The antimetabolite thioguanine was more cytotoxic than 12 for all common cell lines tested.     

咪唑-[1，2-b]哒嗪类mTOR抑制剂的合成及抗肿瘤活性研究

目的设计合成咪唑-[1,2-b]哒嗪类mTOR抑制剂,并对其抗肿瘤活性及构效关系进行初步研究。方法以3-氨基4-溴-6-氯哒嗪、1-（N-Boc-哌啶4-基）溴乙醛等为原料,通过对咪唑[1,2-b]哒嗪环的构建,Suzuki偶联等5步反应得到目标化合物;分别采用SRB染色法、Z′-LYTE（r）法对目标化合物的抗肿瘤活性、mTOR激酶抑制活性进行评价。结果与结论共合成16个未见文献报道的新化合物,其结构经1H-NMR、13C-NMR、HRMS确证;活性测试结果表明,化合物15、16、27等对肿瘤细胞的生长有显著抑制作用。     

Synthesis of imidazo[1,2-a]pyridine derivatives as antiviral agents

The synthesis and antiviral activity of original dibromoimidazo[1,2-a]pyridines bearing a thioether side chain are reported. Molecular modeling was used to identify biophoric structural patterns that are common to 16 compounds. Structure-activity relationship (SAR) studies identified hydrophobicity (logP) as the most important factor for activity. From these SAR studies, the antiviral activity could be predicted.     

Design,Synthesis, and Biological Evaluation of Novel Imidazo[1,2-a]pyridine Derivatives as Potent c-Met Inhibitors

相似文献   

Acanthiline A,a pyrido[1,2-a]indole alkaloid from Chinese mangrove Acanthus ilicifolius

Abstract

Chemical investigation of the leaves and stems of the Chinese mangrove Acanthus ilicifolius Linn. led to the isolation and structure elucidation of one new pyrido[1,2-a]indole alkaloid named acanthiline A (1), together with one known compound aurantiamide acetate (2). Compound 1 has a previously unreported natural product skeleton. The structure elucidation of 1 was based on the analysis of its 1D and 2D NMR and mass spectroscopic data.     

2-(咪唑并[1, 2-a]吡啶-3-基)乙酸的合成工艺改进

目的 改进抗骨质疏松药米诺膦酸的关键中间体2-(咪唑并[1, 2-a]吡啶-3-基)乙酸的制备方法。方法 以2-氧代戊二酸二乙酯为起始原料,经溴代、环合、水解和脱羧4步反应制得目标产物。结果 目标化合物的熔点与¹H-NMR 谱数据与文献报道相符,总收率为40.5%(以2-氧代戊二酸二乙酯计)。结论 与文献报道的方法相比,改进后的工艺路线后处理简单,更有利于工业化生产。     

Synthesis and antimicrobial activity of certain new 1,2,4-triazolo[1,5-a]pyrimidine derivatives

Certain new derivatives of 1,2,4-triazolo[1,5-a]pyrimidines were synthesized through the reaction of 1,2,4-triazolo[1,5-a]pyrimidine-7-ol with ethyl bromoacetate to afford the ethyl acetate ester, which upon hydrazinolysis gives the corresponding hydrazide. The hydrazide is the key intermediate which was used for the synthesis of the target compounds. The structures of the new compounds were assigned by spectral and elemental methods of analyses. The synthesized compounds were tested for their in vitro antibacterial and antifungal activities. Most of the tested compounds showed comparable results with those of ampicillin and fluconazole reference drugs.     

Synthesis of thiazolo[4,5-d]pyrimidine derivatives as potential antimicrobial agents

In this study, we report the synthesis and antimicrobial evaluation of several new thiazolo[4,5-d]pyrimidine derivatives, namely 7-substituted amino-5-methyl-3-phenylthiazolo[4,5-d]pyrimidine-2(3H)-thiones 4a-e, 8, 13, 15, ethyl 2-cyano-2-(7-substituted-5-methyl-3-phenylthiazolo [4,5-d]-pyrimidin-2(3H)-ylidene)acetates 5a-b, 2-(7-substituted-5-methyl-3-phenylthiazolo[4,5-d]pyrimidin-2(3H)-ylidene)malononitriles 6a-b, 5-methyl-7-morpholino-3-phenylthiazolo[4,5-d] pyrimidine-2(3H)-one 7, and 7-[4-(1-substituted-5-phenyl-4,5-dihydro-1H-pyrazolin-3-yl)anilino]-5-methyl-3-phenylthiazolo[4,5-d]pyrimidine-2(3H)-thiones 10-12. Some of the tested compounds were more active against C. albicans than E. coil and P. aeruginosa, and all were inactive against S. aureus.     

Quinoxaline chemistry. Part 16. 4-substituted anilino and 4-substituted phenoxymethyl pyrrolo[1,2-a]quinoxalines and N-[4-(pyrrolo[1,2-a]quinoxalin-4-yl)amino and hydroxymethyl]benzoyl glutamates. Synthesis and evaluation of in vitro biological activity

Twenty eight pyrrolo[1,2-a]quinoxalines bearing at position 4 various substituents related to the moieties present in classical and non classical antifolic agents were prepared and evaluated in vitro for antiproliferative activity. In an in vitro screening performed at NCI, several compounds emerged as potent antiproliferative agents at concentrations ranging between 10 and 100 microM. Interestingly, some of these compounds proved active also against bovine and murine DHFR (Farmaco 53 (1998) 480). More recently, a compound of classical antifolate type has been reported to be a potent inhibitor of hDHFR in vitro (Farmaco 58 (2003) 51). We then synthesized new derivatives that, in our hands, were endowed with in vitro antiproliferative activities as low as 3.4 microM against a panel of cell lines derived from hematological and solid tumours. In addition, a complete screening of cytotoxicity, antiretroviral HIV-1 and antimicrobial activity has been carried out.     

Radiosynthesis of 2-[6-chloro-2-(4-iodophenyl)imidazo[1,2-a]pyridin-3-yl]-N-ethyl-N-[11C]methyl-acetamide, [11C]CLINME,a novel radioligand for imaging the peripheral benzodiazepine receptors with PET

Recently, a new 2-(iodophenyl)imidazo[1,2-a]pyridineacetamide series has been developed as iodine-123-labelled radioligands for imaging the peripheral benzodiazepine receptors using single photon emission tomography. Within this series, 2-[6-chloro-2-(4-iodophenyl)-imidazo[1,2-a]pyridin-3-yl]-N-ethyl-N-methyl-acetamide (CLINME) was considered as an appropriate candidate for positron emission tomography imaging and was isotopically labelled with carbon-11 (T_1/2: 20.38 min) at the methylacetamide side chain from the corresponding nor-analogue using [¹¹C]methyl iodide and the following experimental conditions: (1) trapping at −10°C of [¹¹C]methyl iodide in a 1/2 (v:v) mixture of DMSO/DMF (300 µl) containing 0.7–1.0 mg of the precursor for labelling and 3–5 mg of powdered potassium hydroxide (excess); (2) heating the reaction mixture at 110°C for 3 min under a nitrogen stream; (3) diluting the residue with 0.6 ml of the HPLC mobile phase; and (4) purification using semi-preparative HPLC (Zorbax^® SB18, Hewlett Packard, 250 × 9.4 mm). Typically, starting from a 1.5 Ci (55.5 GBq) [¹¹C]CO₂ production batch, 120−150 mCi (4.44–5.55 GBq) of [¹¹C]CLINME were obtained (16–23% decay-corrected radiochemical yield, n=12) within a total synthesis time of 24–27 min (Sep-pak^®Plus-based formulation included). Specific radioactivities ranged from 0.9 to 2.7 Ci/µmol (33.3–99.9 GBq/µmol) at the end of radiosynthesis. Copyright © 2007 John Wiley & Sons, Ltd.     

Synthesis and antibacterial activity of some derivatives of imidazo[1,2-a]pyridine

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