首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 62 毫秒
1.
An efficient and green reactions of isatins, 3‐amine‐1H‐pyrazole (5‐methyl‐1H‐pyrazol‐3‐amine) and 1,3‐diketone in aqueous medium for the synthesis of novel 1′,7′,8′,9′‐tetrahydrospiro[indoline‐3,4′‐pyrazolo[3,4‐b]quinoline]‐2,5′(6′H)‐dione derivatives were reported in this research. The advantages of this reaction are simple operation, mild‐reaction conditions, wide scope substrate, high yields, and friendly environment. The products were confirmed by IR, 1H NMR, 13C NMR, and HRMS.  相似文献   

2.
The reaction of substituted phenyl isocyanates with 2‐amino‐2‐phenylpropanenitrile and 2‐amino‐2‐(4‐nitrophenyl)propanenitrile has been used to prepare substituted 1‐(1‐cyanoethyl‐1‐phenyl)‐3‐phenylureas. In anhydrous phosphoric acid the first products to be formed from 1‐(1‐cyanoethyl‐1‐phenyl)‐3‐phenylureas are phosphates of 4‐methyl‐4‐phenyl‐2‐phenylimino‐5‐imino‐4,5‐dihydro‐1,3‐oxazoles, which on subsequent hydrolysis give the respective ureidocarboxylic acids. On prolongation of the reaction time, the phosphates of 4‐methyl‐4‐phenyl‐2‐phenylimino‐5‐imino‐4,5‐dihydro‐1,3‐oxazoles rearrange to give phosphates of 5‐methyl‐4‐imino‐3,5‐diphenylimidazolidin‐2‐ones, and these are subsequently hydrolysed to the respective substituted 5‐methyl‐3,5‐diphenylimidazolidin‐2,4‐diones. The ureidocarboxylic acids were also prepared by alkaline hydrolysis of 5‐methyl‐3,5‐diphenylimidazolidin‐2,4‐diones. The 5‐methyl‐3,5‐diphenylimidazolidin‐2,4‐diones and ureidocarboxylic acids were characterised by their 1H and 13C NMR spectra. Structure of the 5‐methyl‐5‐(4‐nitrophenyl)‐3‐phenylimidazolidine‐2,4‐dione was verified by X‐ray diffraction. The alkaline hydrolysis of individual imidazolidine‐2,4‐diones was studies spectrophoto‐metrically in sodium hydroxide solutions at 25 °C. The rate‐limiting step of the base catalysed hydrolysis consists in decomposition of the tetrahedral intermediate. The reaction is faster if electron‐acceptor sub‐stituents are present in the 3‐phenyl group of imidazolidine‐2,4‐dione cycle. The pKa values of individual 5‐methyl‐3,5‐diphenylimidazolidine‐2,4‐diones have been determined kinetically.  相似文献   

3.
The paper describes the synthesis of new 1,3,3‐triary‐1′‐methylspiro[azetidine‐2,3′‐indoline]‐2′,4‐diones from reaction of the 2‐diazo‐1,2‐diarylethanones with 3‐arylimino‐1‐methyl‐2‐indolinones. The compounds have been characterized by satisfactory analytical and spectral (IR, 1H NMR and 13C NMR) data. The diarylketenes, generated in situ from thermal decomposition of the 2‐diazo‐1,2‐diarylethanones, react with azomethine linkage in preference to carbonyl group leading to the formation of products.  相似文献   

4.
Titled spiroazetidinones 1a , 1b undergo reductive cleavage on treatment with excess lithium aluminum hydride forming 3‐benzhydryl‐1‐methylindole as the main product together with a γ‐amino alcohol depending upon the substituent present on the azetidin‐2‐one ring. Treatment of 1a with Ce(IV) ammonium nitrate affords 2‐hydroxy‐N‐(4‐methoxyphenyl)‐2,2‐diphenylacetamide besides the anticipated N‐unsubstituted 2‐azetidinone, whereas a similar treatment of 1‐benzhydryl‐3,3‐diphenyl‐2‐azetidinone 1b affords the ring expansion product 1,3‐oxazolidin‐4‐one. The products have been characterized on the basis of satisfactory analytical and spectral (IR, 1H and 13C‐NMR, DEPT, HMBC) data and their formation is discussed. J. Heterocyclic Chem., (2011).  相似文献   

5.
Thermal decomposition of four tertiary N‐(2‐methylpropyl)‐N‐(1‐diethylphosphono‐2,2‐dimethylpropyl)‐N‐oxyl (SG1)‐based alkoxyamines (SG1‐C(Me)2‐C(O)‐OR, R = Me, tBu, Et, H) has been studied at different experimental conditions using 1H and 31P NMR spectroscopies. This experiment represents the initiating step of methyl methacrylate polymerization. It has been shown that H‐transfer reaction occurs during the decomposition of three alkoxyamines in highly degassed solution, whereas no products of H‐transfer are detected during decomposition of SG1‐MAMA alkoxyamine. The value of the rate constant of H‐transfer for alkoxyamines 1 (SG1‐C(Me)2‐C(O)‐OMe) and 2 ( SG1‐C(Me)2‐C(O)‐OtBu) has been estimated as 1.7 × 103 M?1s?1. The high influence of oxygen on decomposition mechanism is found. In particular, in poorly degassed solutions, nearly quantitative formation of oxidation product has been observed, whereas at residual pressure of 10?5 mbar, the main products originate from H‐atom transfer reaction. The acidity of the reaction medium affects the decomposition mechanism suppressing the H‐atom transfer. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013  相似文献   

6.
7‐Amino‐3‐phenylazo‐2‐methyl‐4H‐pyrazolo[1,5‐a]pyrimidine‐5‐one ( 3 ) was synthesized by the reaction of 5‐amino‐3‐methyl‐4‐phenylazo‐1H‐pyrazole and 2‐aminobenzothiazole with ethyl cyanoacetate in acetic acid at 150°C. Four novel heterocyclic azo disperse dyes were obtained by the coupling of heterocyclic amines‐based diazonium chloride with compound 3 . They were purified and characterized by elemental analysis, FTIR, and 1H NMR. Furthermore, solvatochromic behaviors of related dyes were studied in detail by using ultraviolet–visible absorption spectrometer. The experimental data were supported by density functional theory using b3lyp/cc‐pvtz level calculations, and a detailed analysis of predicted tautomeric structures was made.  相似文献   

7.
Previously unknown 3′‐R1‐5‐R2‐spiro[indoline‐3,6′‐[1,2,4]triazino[2,3‐c]quinazoline]‐2,2′‐(7′H)‐diones and their N‐substituted analogues were obtained via reaction of 6‐R1‐3‐(2‐aminophenyl)‐1,2,4‐triazin‐5‐ones with isatin and its substituted derivatives. It was shown that alkylation of 3′‐R1‐5‐R2‐spiro[indoline‐3,6′‐[1,2,4]triazino[2,3‐c]quinazolin]‐2,2′‐(7′H)‐diones by N‐R3‐chloroacetamides or chloroacetonitrile in the presence of а base proceeds by N‐1 atom of isatin fragment. The spectral properties (1H and 13C NMR spectra) of synthesized compounds were studied, and features of spectral patterns were discussed. The high‐effective anticonvulsant and radical scavenging agents among 3′‐R1‐5‐R2‐spiro[indoline‐3,6′‐[1,2,4]triazino[2,3‐c]quinazolin]‐2,2′(7′H)‐diones and their N‐substituted derivatives were detected. It was shown that compounds 2.2 , 2.8 , and 3.1 exceed or compete the activity of the most widely used in modern neurology drug—lamotrigine on the pentylenetetrazole‐induced seizures model. The aforementioned fact may be considered as a reason for further profound study of synthesized compounds using other pathology models.  相似文献   

8.
The diazo coupling reaction between a tetraaza[14]annulene ( 1 ) and a series of 4‐substituted phenyl‐diazonium tetrafluoroborates yielded the corresponding 7, 16‐disubstituted products. Mass spectra indicate the presence of molecular ion peaks that substantiate the 7,16‐disubstituted products ( 4 ); the lack of olefinic proton signals corresponding to the 7,16‐ position in the 1H nmr spectra of 4 also show that diazo coupling has taken place. Analysis of signals corresponding to the methyl groups of 4 in their 1H and 13C nmr spectra indicate that the imine‐bis‐hydrazone form is present for compounds that do not contain p‐methoxyphenyl groups. However, analysis of methyl signals in the nmr specta of compounds 4 containing p‐methoxyphenyl groups show that the bis‐azo form and the imine‐bis‐hydrazone form are present through tautomerism. Complexation with nickel(II) ion induces the formation of the bis‐ azo structure.  相似文献   

9.
A transition‐metal‐ and oxidant‐free DNP (2,4‐dinitrophenol)‐catalyzed atom‐economical regio‐ and diastereoselective synthesis of monofunctionalized α‐alkynyl‐3‐amino‐2‐oxindole derivatives by C?H bond functionalization of cyclic amines and alkynes with indoline‐2,3‐diones has been developed. This cascade event sequentially involves the reductive amination of indoline‐2,3‐dione by imine formation and cross coupling between C(sp3)?H and C(sp)?H of the cyclic amines and alkynes. This reaction offers an efficient and attractive pathway to different types of α‐alkynyl‐3‐amino‐2‐oxindole derivatives in good yields with a wide tolerance of functional groups. The salient feature of this methodology is that it completely suppresses the homocoupling of alkynes. To the best of our knowledge, this is the first example of a DNP‐catalyzed metal‐free direct C(sp3)?H and C(sp)?H bond functionalization providing biologically active α‐alkynyl‐3‐amino‐2‐oxindole scaffolds.  相似文献   

10.
The cyclization of phenacyl anthranilate has been studied with the aim to develop the synthesis of 2‐(2′‐aminophenyl)‐4‐phenyloxazole. However, a different course of the reaction than expected was observed. 2‐Phenyl‐2‐hydroxymethyl‐4‐oxo‐1,2,3,4‐tetrahydroquinazoline ( 3a ) was formed by the reaction of phenacyl anthranilate ( 2 ) with ammonium acetate under various conditions. 3‐Hydroxy‐2‐phenyl‐4(1H)‐quinolinone ( 4 ) arose by heating compound 3a in acetic acid. The same compound was obtained by melting compound 3a , but the yield was lower. Different types of products resulted in the reaction of compound 3a with acetic anhydride. Under mild conditions acetylated products 2‐acetoxymethyl‐2‐phenyl‐4‐oxo‐1,2,3,4‐tetrahydroquinazoline ( 7a ) and 2‐acetoxymethyl‐3‐acetyl‐2‐phenyl‐4‐oxo‐1,2,3,4‐tetrahydroquinazoline ( 8 ) were prepared. If the reaction was carried out under reflux of the reaction mixture, molecular rearrangement took place to give cis and trans 2‐methyl‐4‐oxo‐3‐(1‐phenyl‐2‐acetoxy)vinyl‐3,4‐dihydroquinazolines ( 9a and 9b ). All prepared compounds have been characterised by their 1H, 13C and 15N NMR spectra, IR spectra and MS.  相似文献   

11.
溴化(a-噻吩甲酰基)甲基三苯鉮1与3-取代苯甲叉基-2,4-戊二酮 2以碳酸钾为碱,在苯中55℃条件下反应,可以较好的收率、高立体选择性地生成反-2-(a-噻吩甲酰基)-3-取代苯基-4-乙氧羰基-5-甲基-2,3-二氢呋喃3。产物结构均经波谱予以确定。本文还提出了生成产物的可能机理。  相似文献   

12.
The reaction of 5,7‐diphenyl‐4,7‐dihydro‐1,2,4‐triazolo[1,5‐a]pyrimidine ( 1 ) with α,β‐unsaturated carbonyl compounds 2a‐f led to the formation of the alkylated heterocycles 3a‐f (Figure 1). However, the reaction of 5‐methyl‐7‐phenyl‐4,7‐dihydro‐1,2,4‐triazolo[1,5‐a]pyrimidine ( 5 ) with 2a‐c yielded under the same conditions the triazolo[5,1‐b]quinazolines 6a‐c (Figure 3). In this case, the alkylation is followed by a cyclocondensation. The structure elucidation of the products is based on ir, ms, 1H and 13C nmr measurements and on an X‐ray diffraction study.  相似文献   

13.
The synthesis and characterization of three new dispiro[indoline‐3,3′‐pyrrolizine‐1′,5′′‐thiazolidine] compounds are reported, together with the crystal structures of two of them. (3RS,1′SR,2′SR,7a′SR)‐2′‐(4‐Chlorophenyl)‐1‐hexyl‐2′′‐sulfanylidene‐5′,6′,7′,7a′‐tetrahydro‐2′H‐dispiro[indoline‐3,3′‐pyrrolizine‐1′,5′′‐thiazolidine]‐2,4′′‐dione, C28H30ClN3O2S2, (I), (3RS,1′SR,2′SR,7a′SR)‐2′‐(4‐chlorophenyl)‐1‐benzyl‐5‐methyl‐2′′‐sulfanylidene‐5′,6′,7′,7a′‐tetrahydro‐2′H‐dispiro[indoline‐3,3′‐pyrrolizine‐1′,5′′‐thiazolidine]‐2,4′′‐dione, C30H26ClN3O2S2, (II), and (3RS,1′SR,2′SR,7a′SR)‐2′‐(4‐chlorophenyl)‐5‐fluoro‐2′′‐sulfanylidene‐5′,6′,7′,7a′‐tetrahydro‐2′H‐dispiro[indoline‐3,3′‐pyrrolizine‐1′,5′′‐thiazolidine]‐2,4′′‐dione, C22H17ClFN3O2S2, (III), were each isolated as a single regioisomer using a one‐pot reaction involving l ‐proline, a substituted isatin and (Z)‐5‐(4‐chlorobenzylidene)‐2‐sulfanylidenethiazolidin‐4‐one [5‐(4‐chlorobenzylidene)rhodanine]. The compositions of (I)–(III) were established by elemental analysis, complemented by high‐resolution mass spectrometry in the case of (I); their constitutions, including the definition of the regiochemistry, were established using NMR spectroscopy, and the relative configurations at the four stereogenic centres were established using single‐crystal X‐ray structure analysis. A possible reaction mechanism for the formation of (I)–(III) is proposed, based on the detailed stereochemistry. The molecules of (I) are linked into simple chains by a single N—H…N hydrogen bond, those of (II) are linked into a chain of rings by a combination of N—H…O and C—H…S=C hydrogen bonds, and those of (III) are linked into sheets by a combination of N—H…N and N—H…S=C hydrogen bonds.  相似文献   

14.
Metalation and C‐C Coupling Reaction of 2‐Pyridylmethylamine: Synthesis and Structures of Methylzinc‐2‐pyridylmethylamide, Tris(trimethylsilyl)methylzinc‐2‐pyridylmethylamide and (Z)‐1‐Amino‐1,2‐bis(2‐pyridyl)ethene The metalation of 2‐pyridylmethylamine with dimethylzinc yields methylzinc‐2‐pyridylmethylamide ( 1 ), which shows a dimer‐trimer equilibrium in solution. Compound 1 crystallizes trimeric with a Zn3N3‐cycle in boat conformation. The endocyclic Zn‐N distances vary between 202 and 206 pm. Heating of this compound in toluene in the presence of dimethylzinc leads to the precipitation of zinc metal and to the formation of a few crystals of bis—[methylzinc‐2‐pyridylmethylamido]‐N, N′‐bis(methylzinc)‐2,3,5,6—tetrakis(2‐pyridyl)‐1,4‐diazacyclohexane ( 2 ). The protolysis of this solution with acetamide gives yellowish (Z)‐1‐amino‐1,2‐dipyridylethene ( 3 ) in a rather poor yield. The enamine tautomer is stabilized by N‐H···N hydrogen bridges. The demanding tris(trimethylsilyl)methyl group at the zinc atom allows the isolation of the dimeric tris(trimethylsilyl)methylzinc‐2‐pyridylmethylamide (4) 2 in good yield. A C‐C coupling reaction of this compound with dimethylzinc is not possible.  相似文献   

15.
This paper describes a method of preparation of new 3,5′‐dioxo‐2′‐phenyl‐1,3‐dihydrospiro[indene‐2,4′‐[1,3]oxazol]‐1‐yl acetate and its 5‐chloro‐ and bromoderivatives as products of interaction of N‐benzoylglycine (hippuric acid) with corresponding ortho‐formylbenzoic acids. The reaction carried out in acetic anhydride media in the presence of piperidine as catalyst. The novel spirocompounds were purified by column chromatography from multicomponent reaction mixtures. The composition of the spiro‐products was confirmed by C, H, N element analysis. The structure was established by IR, MS, 1H‐ and 13C‐NMR analysis including COSY 1H‐13C experiments.  相似文献   

16.
5‐Amino‐thieno[3,2‐c]pyrazole derivative 2 was prepared by Gewald reaction in a one‐pot procedure. The amino group of compound 2 like primary aromatic amine formed the diazonium salt when treated with NaNO2/HCl, followed by coupling with different nucleophiles to yield the azo coupling products 3a – d . The reactivity of 5‐amino‐thienopyrazole 2 has been investigated towards different electrophilic reagents such as aromatic aldehydes, alkyl halide, acid chloride, acid anhydride, phenyl isothiocyanate, carbon disulfide, ethyl glycinate, and thioacetamide, which afforded the reaction products 4 – 14 , respectively.  相似文献   

17.
A reaction of diethyl 2,4,6‐trimethyl‐1,4‐dihydropyridine‐3,5‐dicarboxylate with 1, 2, and more equivalents of N‐bromosuccinimide (NBS) in methanol was investigated by NMR spectroscopy at a temperature interval ranging from 25 to 40°C. The reaction was found to proceed through several steps. The structures of the intermediates diethyl 3‐bromo‐2,4,6‐trimethyl‐3,4‐dihydropyridine‐3,5‐dicarboxylate, diethyl 3‐bromo‐2‐methoxy‐2,4,6‐trimethyl‐1,2,3,4‐tetrahydropyridine‐3,5‐dicarboxylate, and diethyl 3,5‐dibromo‐2‐methoxy‐2,4,6‐trimethyl‐2,3,4,5‐tetrahydropyridine‐3,5‐dicarboxylate were identified by multinuclear (1H, 13C, and 15N) NMR spectral data. The optimal structures of all species participating in the reaction as well as changes in their relative energies along with the proposed pathway of the reaction were analyzed by quantum‐chemical calculations. The mechanism of bromination of diethyl 2,4,6‐trimethyl‐1,4‐dihydropyridine‐3,5‐dicarboxylate with NBS in methanol was found to favor the bromination in the 2,6‐methyl side chains as the only products in full agreement with experimental observations.  相似文献   

18.
The reaction between chloramine and 2‐methylindoline was studied at pH 12.89, T = 40°C, and for different initial concentrations of reactants. The interaction includes two concurrent bimolecular mechanisms leading to 1‐amino‐2‐methylindoline and 2‐methylindole. The rate laws were determined at the first moments of the reaction by using a differential method. By considering the totality of the reactions that occur in the medium, an appropriate mathematical model was developed. It permits to follow the evolution of the system over time and to calculate the final yields of reaction products. An optimization in terms of the initial contents of 2‐methylindoline and chloramine was performed. It indicated that the maximum yield of 1‐amino‐2‐methylindoline does not exceed 56%. The results show the limit of the Raschig process for the synthesis of indolic hydrazines in aqueous medium. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 575–584, 2002  相似文献   

19.
The synthesis of 1‐amino‐2‐methylindoline by the Raschig process was undertaken in aqueous solution. The principal side reaction that occurs in the medium is the oxidation of 1‐amino‐2‐methylindoline formed by chloramine. To increase the yield of 1‐amino‐2‐methylindoline, its oxidation by chloramine was studied by GC and HPLC at various concentrations of reactants and for a pH interval ranging between 9.9 and 13.5. The reaction is bimolecular and exhibits a specific acid catalysis. In alkaline medium, 1‐amino‐2‐methylindole is the principal product. The enthalpy and entropy of activation were determined at pH 12.89. In unbuffered solution, the interaction was autocatalyzed by the ammonium ions formed, which indicates a competitive oxidation of neutral and ionic forms of 1‐amino‐2‐methylindoline by chloramine. A mathematical treatment based on one implicit equation allows a quantitative interpretation of all the phenomena observed over the above pH interval. It takes both acid–base dissociation equilibrium and alkaline hydrolysis of chloramine into account. © 2002 Wiley Periodicals, Inc. Int J Chem Kinet 34: 515–523, 2002  相似文献   

20.
A new series of pyrazolone based azo acid dyes (3a–g) has been synthesized starting from 1‐(p‐sul‐phophenyl)‐3‐methyl‐5‐pyrazolone (1). The synthetic methodology included the nitrosation of p‐sulphophenyl methyl pyrazolone followed by reduction, diazotization and coupling with Naphthol AS derivatives (2a–f), in alkaline medium to yield different acid dyes. Multichromic metal complexes of these dyes (5a–f, 6a–f and 7a–f) with 3d transition metals Chromium, Iron and Copper were also synthesized. The structures of all of newly synthesized compounds were confirmed by analytical data and spectroscopic techniques. The synthesized dyes were applied on leather to assess their light fastness, wash fastness and rubbing fastness and were shown to exhibit high values of 4–5 for majority of dyes.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号