Pharmacological evaluation of some new 2-substituted pyridine derivatives

In the present study, a series of 2-substituted-pyridines were synthesized and characterized by IR, (1)H-NMR and Elemental Analysis. The compounds were assayed against seizures induced by maximal electro shock (MES) and pentylenetetrazole (scMet). Neurologic deficit was evaluated by the rotarod test. The decrease in the elevated motor activity by introceptive chemical stimuli (amphetamine antagonistic activity) was studied at the dose level of 25 and 50 mg/kg, antihistaminic and cardiac activity were also studied. All the compounds exhibited significant anticonvulsant activity. Compounds 2-(2'-piperazino-ethanoxy)pyridine, 2-(3'-morpholino-2'-hydroxypropyloxy)pyridine, 2-(3'-piperidino-2'-hydroxypropyloxy)pyridine and 2-(3'-piperazino-2'-hydroxypropyloxy)pyridine were most active of the series against MES-induced seizures. Compounds 2-(2'-piperazino-ethanoxy)pyridine, 2-(2'-phenylamino-ethanoxy)pyridine, 2-(3'-imidazolo-2'-hydroxypropyloxy)pyridine, 2-(3'-methylamino-2'-hydroxypropyloxy)pyridine and 2-(3'-piperidino-2'-hydroxypropyloxy)pyridine exhibited significant decrease in the elevated motor activity at the dose of 50 mg/kg. Remarkable sympathetic blocking activity was observed with 2-(3'-piperazino-2'-hydroxypropyloxy)pyridine, 2-(3'-piperidino-2'-hydroxypropyloxy)pyridine and 2-(3'-imidazolo-2'-hydroxypropyloxy)pyridine only. Compounds 2-(2'-morpholino-ethanoxy)pyridine, 2-(2'-piperidino-ethanoxy)pyridine, 2-(2'-piperazino-ethanoxy)pyridine, 2-(2'-imidazolo-ethanoxy)pyridine, 2-(2'-diphenylamino-ethanoxy)pyridine, 2-(2'-diethanolamino-ethanoxy)pyridine, 2-(2'-phenylamino-ethanoxy)pyridine and 2-(2'-(4"-hydroxy)phenylamino-ethanoxy)pyridine exhibited significant blocking of histamine induced contraction on guinea pig ileum.     

2-氧代-5,6,7,7a-四氢噻吩并[3,2-c]吡啶的合成

N-乙氧羰基-4-哌啶酮经Vilsmerier氯化甲酰化反应、在碳酸钾作用下与巯基乙酸乙酯环合制得6,7-二氧-4H-噻吩并[3,2-c]吡啶-2,5-二羧酸二乙酯(4),再经肼解、叠氮化、重排及脱保护反应制得2-氨基-6,7-二氢-4H-噻吩并[3,2-c]吡啶-5-羧酸乙酯盐酸盐(8),8经重氮化、水解后再由氢氧化钾碱解、成盐,制得普拉格雷的关键中间体2-氧代-5,6,7,7a-四氢噻吩并[3,2-c]毗啶,总收率约25％.     

2-氯-4-(哌啶-1-基甲基)吡啶的合成

2-氨基-4-甲基吡啶在过量浓盐酸/亚硝酸钠作用下与氯化亚铜/盐酸反应后,在偶氮二异丁腈(AIBN)作用下与硫酰氯反应制得2-氯-4-(氯甲基)吡啶,再在DMF中与哌啶缩合,得到拉呋替丁的关键中间体2-氯-4-(哌啶-1-基甲基)-吡啶,总收率约62％.     

Novel microtubule-interacting phenoxy pyridine and phenyl sulfanyl pyridine analogues for cancer therapy

Current microtubule inhibitory agents used in the clinic to treat cancer have severe side effects, and development of resistance is frequent. We have evaluated the antitumor effect of a novel 30-compound library of phenoxy pyridine and phenyl sulfanyl pyridine derivatives. MTT assays revealed that, of all 30 compounds tested, compounds 2 and 3 showed the largest decrease in proliferation (low muM range) against Panc1 and HS766T human pancreatic cancer cells. Flow cytometry experiments with MCF7 breast cancer cells showed a G2/M arrest comparable to that of colcemid. Immunofluorescence staining demonstrated complete disappearance of intracellular microtubules. Tubulin assembly assays, however, showed a dose-dependent decrease in tubulin assembly with compound 3 that seemed limited to about 50% of the control reaction. With compound 2 treatment, there was only a delay in the onset of assembly, with no effect on the extent of the reaction. Taken together, our results show that these novel microtubule inhibitors have promising anticancer activity and can be potentially used to overcome paclitaxel resistance in the clinical setting.     

2-[(Phenylthio)methyl]pyridine derivatives: new antiinflammatory agents

2-[(Phenylthio)methyl]pyridine derivatives inhibited the dermal reverse passive Arthus reaction (RPAR) in the rat. In the same model, indomethacin was inactive, and hydrocortisone was active. Compounds Ia-d also significantly reduced exudate volume and white blood cell accumulation in the pleural RPAR. This pattern of activity was similar to that of hydrocortisone and different from that of indomethacin.     

2,4,6-三(1H-苯并咪唑-2-基)吡啶和2,4,6-三(1H-咪唑并[4,5-c]吡啶-2-基)吡啶的微波辐射合成

苯并咪唑类衍生物及其金属配合物具有良好的生物活性,可用作抗寄生虫药和质子泵抑制剂等。近年来的药理研究证明,此类化合物对肝炎、骨炎、脾炎等也具有治疗和预防作用,还可作为有机合成反应的中间体。三苯并咪唑类和三吡啶并咪唑类化合物亦具有类似的生理活性。     

2-Acetylpyridine thiosemicarbazones XI: 2-(alpha-Hydroxyacetyl)pyridine thiosemicarbazones as antimalarial and antibacterial agents

A series of 2-(alpha-hydroxyacetyl)pyridine thiosemicarbazones was synthesized as potential antimalarial and antibacterial agents. Their synthesis was achieved by the condensation of N4-mono- or N4,N4-disubstituted thiosemicarbazides with 2-(alpha-hydroxyacetyl)pyridine. The latter was prepared by selective bromine oxidation of (2-pyridinyl)-1,2-ethanediol. The new compounds show potent inhibitory activity against penicillin-sensitive as well as penicillin-resistant Neisseria gonorrhoeae (MIC, 0.5-0.004 micrograms/mL), against Neisseria meningitidis (MIC, 0.5-0.032 micrograms/mL), and Staphylococcus aureus (MIC, 0.5-2 micrograms/mL). Good in vitro antimalarial effects against Plasmodium falciparum (Smith strain; ID50, 6.7-38 ng/mL) were observed in most of these new agents, but only 3 of 12 compounds exhibit moderate in vivo activity against Plasmodium berghei. These new agents appear to be less toxic to the host and more water soluble than the corresponding 2-acetylpyridine thiosemicarbazones.     

Reactions with cyanothioacetamide derivatives: Synthesis of several new pyridine and annelated pyridine derivatives

Several new pyridine, pyridinethione, pyrazole[3,4-b]-pyridine, pyrido [1,2-a]-1,3-thiazine and pyrido[1,2-a]pyridine thione derivatives have be synthesised via the reactions of 2-methyl-3-ethoxycarbonyl-4-phenyl-5-cyano-1,4,5,6-tetrahydro-pyridine-6-one 2 with different reagents. The structures of the newly synthesised derivatives were established on the basis of elemental analyses and spectal data studies.     

Studies on the biotransformation and anti-ulcer effects of 2-(nicotinoylaminoethanesulfonylamino)pyridine

Investigations were made of 2-(nicotinoylaminoethanesulfonylamino)pyridine (NTP), a new compound with anti-ulcer effects, to clarify the relationship between its biotransformation and pharmacological effects. The effect of NTP was investigated by using two types of experimental gastric ulcer models in rats. The anti-ulcer effect was revealed to be an action of NTP itself. In order to study the biotransformation of NTP, a quantitative analysis method by HPLC was established. When NTP was orally administered to rabbits, 2-(aminoethanesulfonylamino)pyridine (TP), which is a metabolite of NTP, appeared in plasma and lymph. When NTP was orally administered to rabbits to investigate its distribution in organs, a massive amount of NTP and TP appeared in various organs within 7 hr after administration. We conclude that the pharmacological effect of NTP appears to be associated mainly with the unchanged substance.     

2-Acetylpyridine thiosemicarbazones. 10. 2-Propionyl-, 2-butyryl-, and 2-(2-methylpropionyl)pyridine thiosemicarbazones as potential antimalarial agents

In view of the antimalarial properties observed for many 2-acetylpyridine thiosemicarbazones, a series of N4,N4-disubstituted thiosemicarbazones derived from 2-propionyl-, 2-butyryl-, and 2-(2-methylpropionyl)pyridine was prepared for evaluation against the malaria parasite, Plasmodium berghei, in the mouse. The thiosemicarbazones were made by the reaction of methyl hydrazinecarbodithioate with a 2-acylpyridine to give the intermediate methyl 3-[1-2-pyridinyl)alkylidene]hydrazinecarbodithioates. Reaction of the latter with 3-azabicyclo[3.2.2]nonane, 1-(2-pyridinyl)piperazine, or 1H-hexahydroazepine gave the requisite thiosemicarbazones. The three thiosemicarbazones derived from 3-azabicyclo[3.2.2]nonane were most effective, the greatest potency being exhibited by 3-azabicyclo-[3.2.2]nonane-3-thiocarboxylic acid 2-[1-(2-pyridinyl)butylidene]hydrazide (4) which cured 4/5 mice at a dose of 160 mg/kg. In contrast to the related thiosemicarbazones derived from 2-acetylpyridine, virtually no toxic effects were observed in the series described here.     

Discovery of a novel class of pyridine derivatives that selectively inhibits mutant isocitrate dehydrogenase 2

This paper presents synthesis and structure–activity relationship of pyridine derivatives as inhibitors of mutant isocitrate dehydrogenase 2 (IDH2). A series of 2,4,6‐trisubstituted pyridine derivatives have been prepared and evaluated in vitro. Among these compounds, 14n exhibited excellent inhibition activity with the IC₅₀ of 54.6 nm , which is approximately onefold improvement compared to drug candidate AG‐221 (Enasidenib) that is in Phase III trial. Exquisite selectivity of 14n for IDH2 R140Q mutant isoform was demonstrated by the poor activity against the wild‐type IDH1 and IDH2.     

Reaction of pyridine derivatives with chlorodinitrobenzene

The Reaction of Pyridine Derivatives with Chlorodinitrobenzene Pyridine, nicotinamide and nicotine react with 1-chloro-2,4-dinitrobenzene to the corresponding pyridinium salts which by treating with alkali give glutaconic aldehydes free from alkali cations. By heating with methanol the glutaconic aldehydes of pyridine and nicotine give dinitroanisole which was not found in the case of nicotinamide. With hydrochloric acid the glutaconic aldehydes give dinitroaniline. The cleavage of the pyridine ring in all cases takes place at the C-2 atom.