超声辐射下几种腙类化合物的合成研究

以乙酰丙酮为起始原料,经三步反应制得了w-溴代-1-苯基-5-甲基吡唑-4-乙酮(5).中间体5在超声波辐射下与芳基乙酮缩氨基硫脲类化合物(1a-1g)反应生成了新型的N-(1-芳基乙酮)-N1-[(1-苯基-5-甲基吡唑-4-基)噻唑-2-基]腙(6a-6g).以1H NMR,IR,MS和元素分析对产物进行了确证及表...     

Access to Silylated Pyrazole Derivatives by Palladium‐Catalyzed C−H Activation of a TMS group

A simple and efficient approach to new silylated heterocycles of potential interest in medicinal chemistry is presented. A set of bromophenyl trimethylsilyl pyrazole intermediates can be transformed by direct organometallic routes into two families of regioisomeric iodoaryl substrates; using either arylzinc or aryllithium chemistry, the TMS group remains on the pyrazole ring or translocates to the aryl moiety. These two families can then be efficiently transformed into benzo silino pyrazoles thanks to a single‐step cyclization relying on the Pd‐catalyzed activation of a non‐activated C(sp³)?H bond alpha to a silicon atom. The experimental conditions used, which are fully compatible with the pyrazole ring, suggest that this reaction evolves through a concerted metalation–deprotonation (CMD) mechanism.     

Synthesis,Crystal Structure and Biological Activity of 2-(1-(3-Bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carbonyl)piperidin-4-yl)-N-isopropyl-1,3-thiazole-4-carboxamide

The title compound 2-(1-(3-bromo-1-(3-chloropyridin-2-yl)-1H-pyrazole-5-carbonyl)piperidin-4-yl)-N-isopropylthiazole-4-carboxamide(C21H22Br Cl N6O2 S,Mr = 536.04) has been synthesized,and its structure was characterized by IR spectra,1H-NMR,13C-NMR,EA,and single-crystal X-ray diffraction.The crystal of the title compound belongs to monoclinic system,space group P/c with a = 15.146(3),b = 11.573(2),c = 26.937(5) ?,β = 103.64(3)°,V = 1839.0(6) ?3,Z = 4,Dc = 1.557 g/cm3,μ(Mo Ka) = 0.71073 mm-1,F(000) = 2192,R = 0.0601 and w R = 0.1392.There exist one intramolecular hydrogen bond at N–H···N and four intermolecular weak interactions at O(2)···H(1),Cl(1)···H(12),O(1)···Cl(1) and S(1)···O(2).Bioassay results indicated that the title compound had good fungicidal and antiviral activities against tobacco mosaic virus.     

Synthesis of New Benzopyrano[2,3-c]pyrazoles and 3-triazolonyliminocoumarins From 3-cyano Iminocoumarin Derivatives

Synthesis of benzopyrano[2,3-c]pyrazoles and 3-triazolonyliminocoumarins was successfully performed using heterocyclization of 3-cyano iminocoumarin or their N-ethoxycarbonylated derivatives with semicarbazide reagents. Elemental analysis, infrared, and ¹H NMR spectral data confirmed the molecular structure of the newly synthesized compounds.     

Convenient synthesis of spiro[indoline-3,4'-pyrano[2,3-c]pyrazole] and spiro[acenaphthyl-3,4'-pyrano[2,3-c]pyrazoles] via fourcomponent reaction

The base promoted four-component reaction of hydrated hydrazine, dimethyl acetylenedicarboxylate, isatines and malononitrile (ethyl cycanoacetate) in ethanol afforded polysubstituted spiro[indoline-3,4‘-pyrano[2,3-c]pyrazoles] and spiro[acenaphthyl-3,4-pyrano[2,3-c]pyrazoles]     

Supramolecular dimeric structures of pyrazole-containing meso-oxo carbaphlorin analogues

Synthesis and properties of a novel meso-oxo carbaphlorin analogue embedded with an N-free pyrazole moiety are described. The N-benzyl precursor was prepared by a [3 + 1]-MacDonald condensation of N-benzyl pyrazole dialdehyde and β-alkyl-substituted tripyrrane dicarboxylic acid and subsequent oxidation by ferric chloride. Upon deprotection of the benzyl group, the resulting N-free oxophlorin analogue formed a unique supramolecular dimer through mutual hydrogen bonding interactions between the pyrazole NH and meso-carbonyl group. The assembled behaviour was characterised by various spectroscopies, X-ray crystallographic analysis and vapour pressure osmometry. Under the similar reaction conditions, the condensation of meso-phenyl-substituted tripyrrane derivative afforded an unprecedented tetrapyrrolic macrocycle fused with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone unit at their α-pyrrolic positions. The X-ray crystallographic analysis of the macrocycle revealed a twisted core structure, and nonaromatic nature was elucidated.     

An Efficient One‐pot Synthesis of Aryl‐substituted 1‐(Thiazol‐2‐yl)‐1H‐pyrazole‐3‐carboxylates via a Hantzsch Synthesis‐Knorr Reaction Sequence

The treatment of α‐bromoalkyl aryl ketones and 2‐(propan‐2‐ylidene)hydrazine carbothioamide afforded 4‐aryl‐2‐(2‐(propan‐2‐ylidene)hydrazinyl)thiazoles via a Hantzsch‐thiazole synthesis, which reacted with 4‐aryl‐2,4‐diketoesters via a sequential Knorr‐pyrazole reaction to deliver a variety of aryl‐substituted ethyl 1‐(thiazol‐2‐yl)‐1H‐pyrazole‐3‐carboxylates in a one‐pot fashion with moderate to high yields. The key intermediates 4‐aryl‐2,4‐diketoesters, existing as its enolic lithium salt, were synthesized in situ by a high‐yield tert‐BuOLi‐mediated Claisen condensation of alkylphenones and diethyl oxalate. This class of elegant molecule comprises aryl groups on the two different heterocyclic cores, and the configurations of two representative molecules were determined by single crystal X‐ray crystallography.     

A four-component synthesis of dihydropyrano[2,3-c]pyrazoles in a new water-based worm-like micellar medium

Cocamidopropyl betaine (CAPB) as a biodegradable surfactant produces a new worm-like micellar medium for rapid synthesis of dihydropyrano[2,3-c]pyrazoles via a four-component reaction of aldehydes, ethyl acetoacetate, malononitrile, and hydrazine hydrate at 50–60 °C. This zwitterionic surfactant was superior to anionic, cationic, and nonionic alternatives for accessing high yields of pure products without the use of any organic solvent. While the reaction medium was reusable, simple isolation of products, mild reaction conditions, low loading of CAPB for critical micelle concentration and short reaction times are additional advantages of this green procedure.     

3,5-二苯基吡唑的合成与晶体结构

合成了3,5-二苯基吡唑,通过了元素分析、红外光谱和核磁共振氢谱对其结构进行了表征.用X-射线单晶衍射测定了该化合物的晶体和分子结构.化合物晶体为单斜晶系,空间群C2/c,晶胞参数a=16.942（2）,b=17.153（2）,c=17.658（2）,α=90°,β=109.600（2）°,γ=90°,Z=16,V=4834.4（12）3,Dc=1.555g/cm3,μ=0.073mm-1,F（000）=868,差值电子密度最高和最低峰为147和-307e.nm-3.