Regioselective Synthesis of 1,3,5-Trisubstituted Pyrazoles

Abstract

A new and a simple approach toward synthesis of 1,3,5-trisubstituted pyrazoles from chalcone arylhydrazones via oxidative cyclization has been achieved. 2,3-Dichloro-5,6-dicyano-1,4-benzoquinone was successfully used as an oxidizing agent to give excellent yields of pyrazoles.     

一氧化氮氧化芳构化1,3,5-三取代吡唑啉

室温下, 一氧化氮氧化芳构化1,3,5-三取代吡唑啉, 高产率地得到了相应的产物1,3,5-三取代吡唑. 产物结构通过各种谱图数据确定. 该反应具有反应条件温和、操作简便易行以及产率高等优点.     

Synthesis of 1,3,5-Trisubstituted Pyrazoles and Hydrazones Using Fe3O4@CeO2 Nanocomposite as an Efficient Heterogeneous Nanocatalyst

Russian Journal of Organic Chemistry - Pyrazoles and hydrazones, as two significant kinds of potentially bioactive compounds, were produced with good to excellent yields by condensation of...     

Synthesis of Novel Isothionucleosides as Potential Antiviral Agents

The synthesis of novel isothionucleosides is described. The thioether moiety was prepared via a highly regioselective opening of chiral thiirane 9 with vinylmagnesium bromide.     

多取代吡唑合成最新研究进展

吡唑是一类重要的五元含氮杂环化合物,广泛存在于许多天然产物、生物活性分子和药物分子中,而且是一类重要的有机合成中间体.因此,近年来吡唑及其衍生物的合成引起了科学家们的极大兴趣,并得以迅速发展.对近年来多取代吡唑的合成新方法进行了综述,以期对相关领域的研究起到一定的辅助与推动作用.     

Some Novel Thiazoline and Thiazolidinone Derivatives Surmounted on Substituted Pyrazole Moieties as Potential Antipyretic Agents

Six novel series of substituted thiazoline (V, VI, VII and VIII) and thiazolidinone derivatives (IX and X) resulting from 2,3-dihydro-1, 5-dimethyl-3-oxo-2-phenyl-1H-pyrazole-4-carbaldehyde (I) and 1-phenyl-3-p-tolyl-1H-pyrazolc-4-carbaldehyde (II) were synthesized. The course of this synthesis included the preparation of two new scries of disubstituted thiosemicarbazone precursors (III and IV) which were cyclized with phenacyl bromide, ethyl 2-chloroacetoacetate as well as ethyl bromoacetatc to afford the target thiazolines and thiazolidinoncs. The antipyretic activity of some representative compounds was performed.     

Iodobenzene Diacetate Mediated Oxidation of N-Substituted Hydrazones of Chalcones: An Efficient Regioselective Synthesis of 1,3,5-Trisubstituted Pyrazoles

Iodobenzene diacetate, a relatively benign nonmetallic oxidant, has been utilized efficiently for the oxidation of N-substituted hydrazones of chalcones to afford 1,3,5-trisubstituted pyrazoles under mild reaction conditions.     

99mTcN核标记的新型心肌灌注显像剂的研究

通过配体交换反应制备了[99mTcN(PNP5)(DEDC)]+和[99mTcN(PNP5)(DPODC)]+两种新配合物, 其放化纯度均大于90%. 生物性能研究结果表明: 两种配合物在小鼠心肌中的初始摄取高, 肝、肺等非靶组织清除快, 靶/非靶比高, 有利于早期心肌显像. 其中, [99mTcN(PNP5)(DEDC)]+在小鼠中的性质较优, 且其在狗体内的性质接近99mTc-tetrofosmin, 有望成为一种新型心肌灌注显像剂.     

Multicomponent Reaction for Synthesis of N-Arylsulfonyl Pyrazoles

A synthesis of functionalized N-arylsulfonyl pyrazoles from the multicomponent reaction of arylsulfonyl hydrazones and dialkyl acetylenedicarboxylates in the presence nucleophilic compounds such as pyridine, isoquinoline, or triphenylphosphine, in good yields, is described.

[Supplementary materials are available for this article. Go to the publisher's online edition of Synthetic Communications® for the following free supplemental resources: Full experimental and spectral details.]     

Synthesis of Novel Aryloxy Propanoyl Thiadiazoles as Potential Antihypertensive Agents

2‐Amino‐5‐aryl/alkyl‐1,3,4‐thiadiazoles 3a‐e were synthesized from aliphatic and aromatic acids and thiosemicarbazide. These 2‐amino‐5‐aryl/alkyl‐1,3,4‐thiadiazoles 3a‐e were condensed with 2‐(naphthalenyloxymethyl) oxirane 4a‐b to prepare some naphthalenyloxy‐propanol amine derivatives 5a‐j . These compounds were synthesized as potential antihypertensive agents.     

Design and Synthesis of Some New Benzimidazole Containing Pyrazoles and Pyrazolyl Thiazoles as Potential Antimicrobial Agents

A new class of bis heterocycles‐benzimidazolyl pyrazoles were prepared from the Michael acceptor (E)‐3‐(1H‐benzimidazol‐2‐yl)‐1‐aryl‐prop‐2‐en‐1‐one. The thiamide group was exploited to develop thiazole ring on treatment with p‐fluorophenacyl bromide to get tris heterocycles. All the lead compounds were tested for antimicrobial activity. The compound 7d having nitro substituent on the aromatic ring showed greater antimicrobial activity particularly against Pseudomonas aeruginosa and Penicillium chrysogenum.     

Oxidative Cyclization of Chalcones in the Presence of Sulfamic Acid as Catalyst. Synthesis,Biological Activity,and Thermal Properties of 1,3,5-Trisubstituted Pyrazoles

Russian Journal of Organic Chemistry - 1-Aroyl-3,5-diaryl-1H-pyrazoles were synthesized by oxidative cyclization of chalcones with benzohydrazide and 4-nitrobenzohydrazide using sulfamic acid as a...     

Bioactives of Momordica charantia as Potential Anti-Diabetic/Hypoglycemic Agents

Momordica charantia L., a member of the Curcubitaceae family, has traditionally been used as herbal medicine and as a vegetable. Functional ingredients of M. charantia play important roles in body health and human nutrition, which can be used directly or indirectly in treating or preventing hyperglycemia-related chronic diseases in humans. The hypoglycemic effects of M. charantia have been known for years. In this paper, the research progress of M. charantia phytobioactives and their hypoglycemic effects and related mechanisms, especially relating to diabetes mellitus, has been reviewed. Moreover, the clinical application of M. charantia in treating diabetes mellitus is also discussed, hoping to broaden the application of M. charantia as functional food.     

2,6-吡啶二甲酰双吡唑衍生物的合成

合成了4个吡唑及其衍生物,其结构经元素分析,IR,1^HNMR和^13CNMR等表征。     

Pyrazoles and Pyrazolines as Anti-Inflammatory Agents

The five-membered heterocyclic group of pyrazoles/pyrazolines plays important role in drug discovery. Pyrazoles and pyrazolines present a wide range of biological activities. The synthesis of the pyrazolines and pyrazole derivatives was accomplished via the condensation of the appropriate substituted aldehydes and acetophenones, suitable chalcones and hydrazine hydrate in absolute ethanol in the presence of drops of glacial acetic acid. The compounds are obtained in good yields 68–99% and their structure was confirmed using IR, ¹H-NMR, ¹³C-NMR and elemental analysis. The novel derivatives were studied in vitro for their antioxidant, anti-lipid peroxidation (AAPH) activities and inhibitory activity of lipoxygenase. Both classes strongly inhibit lipid peroxidation. Compound 2g was the most potent lipoxygenase inhibitor (IC₅₀ = 80 µM). The inhibition of the carrageenin-induced paw edema (CPE) and nociception was also determined, with compounds 2d and 2e being the most potent. Compound 2e inhibited nociception higher than 2d. Pyrazoline 2d was found to be active in a preliminary test, for the investigation of anti-adjuvant-induced disease (AID) activity. Pyrazoline derivatives were found to be more potent than pyrazoles. Docking studies of the most potent LOX inhibitor 2g highlight hydrophobic interactions with VAL126, PHE143, VAL520 and LYS526 and a halogen bond between the chlorine atom and ARG182.     

Synthesis of β-Aminoethyl-substituted Pyrazoles

Methods have been developed for the synthesis of 3,5-dimethyl-4-(2-N-mono- and -disubstituted and also unsubstituted aminoethyl)pyrazoles from 1,1-diacetylcyclopropane.     

3,6-二脱氧达格列净的合成及其降血糖活性研究

利用达格列净作为原料经过两条路线合成了3,6-二脱氧达格列净,其3,6-二脱氧的位置进一步经过了NOE技术确认,体外h SGLT2抑制试验和大鼠尿糖排泄试验表明,所合成的3,6-二脱氧达格列净几乎没有SGLT2抑制活性,说明SGLT2抑制剂结构中葡萄糖片段上3-OH和6-OH同时脱除会导致SGLT2抑制剂完全丧失活性。