2-溴甲基-3-(二溴甲基)喹喔啉的合成研究

以2，3－二（溴甲基）喹喔啉为原料，以N－溴琥珀酰亚胺为溴化试剂合成了2－溴甲基－3－（二溴甲基）喹喔啉（1），1是Diels-Alder环加成反应中形成含杂原子环的C60衍生物的一种重要中间体。通过IR，^1H NMR,^13C NMR,DEPT谱和MS对其进行了结构表征。     

Synthesis of indan-based unusual alpha-amino acid derivatives under phase-transfer catalysis conditions

Conformationally constrained cyclic alpha-amino acid derivatives were synthesized under solid-liquid phase-transfer catalysis conditions. This methodology involves the bis-alkylation of ethyl isocyanoacetate with various alpha,alpha'-dibromo-o-xylene derivatives [alpha,alpha'-dibromo-o-xylene 5, 2,3-bis(bromomethyl)-1, 4-dimethoxybenzene 6, 1,2-bis(bromomethyl)-4,5-dibromobenzene 7, 2, 3-bis(bromomethyl)naphthalene 8, 1,8-bis(bromomethyl)-naphthalene 9, 6,7-bis(bromomethyl)-2,2-dimethyl-1H-phenalene-1,3(2H)-dione 10, 2, 3-bis(bromomethyl)-1,4-anthraquinone 11, 6, 7-bis(bromomethyl)quinoxaline 12, 3,4-bis(bromomethyl)furan 13, 1,2, 4,5-tetrakis(bromomethyl)benzene 28, and hexakis(bromomethyl)benzene 30] using potassium carbonate as a base and tetrabutylammonium hydrogensulfate as a phase-transfer catalyst to give corresponding isonitrile derivatives, which upon hydrolysis with HCl in ethanol gave amino esters. Using this method electron-deficient as well as electron-rich and halogen-substituted indan-based alpha-amino acids were prepared. The preparation of bis-indan as well as tris-indan alpha-amino esters is also described.     

Controlling the outcome of an N-alkylation reaction by using N-oxide functional groups

Covalent modifiers of proteins are of importance in chemical proteomics, an emerging chemical technology used to assign protein function. In this study, high-field (1)H NMR techniques were used to analyze the reaction of the bioactive compound, 2,3-bis(bromomethyl)quinoxaline 1,4-dioxide, with amines (a model system for proteins containing nitrogen-based nucleophiles). Unexpectedly, the results show that a double nucleophilic substitution reaction involving 2 equiv of the amine is preferred to an intramolecular cyclization pathway. A direct comparison with the reaction carried out on a substrate lacking the N-oxide functional groups is also provided. X-ray crystal structures and computational studies are used to rationalize the observed differences in reactivity between the two systems.     

2,3-二溴甲基喹喔啉与C60的Diels-Alder反应

Ｃ60 是富勒烯家族的一员[1] 。Ｃ60 分子的发现是Ｈ .Ｗ .Ｋｒｏｔｏ和Ｒ .Ｅ .Ｓｍａｌｌｅｙ等人于 1 985年 ,在氦气流中以激光蒸发石墨 ,从而获得以Ｃ60 为主的质谱图的 ,并在实验室制得了Ｃ60 分子[2 ] 。 1 990年德国科学家Ｋｒａｔｓｃｈｍｅｒ,Ｗ和美国科学家Ｈｕｆｆｍａｎ ,Ｄ .Ｒ .等用电弧法克量级制备Ｃ60 获得成功[3] 。从此 ,世界范围内掀起了一股Ｃ60 的研究热 ,对Ｃ60 进行各种化学修饰更是化学家的热门课题 ,经化学修饰的Ｃ60 衍生物具有潜在的应用前景。近几年 ,Ｃ60 化学反应的研究十分活跃 ,氧化反应、还原反应、聚合…     

Synthesis of 3-methoxyazetidines via an aziridine to azetidine rearrangement and theoretical rationalization of the reaction mechanism

The synthetic utility of N-alkylidene-(2,3-dibromo-2-methylpropyl)amines and N-(2,3-dibromo-2-methylpropylidene)benzylamines was demonstrated by the unexpected synthesis of 3-methoxy-3-methylazetidines upon treatment with sodium borohydride in methanol under reflux through a rare aziridine to azetidine rearrangement. These findings stand in contrast to the known reactivity of the closely related N-alkylidene-(2,3-dibromopropyl)amines, which are easily converted into 2-(bromomethyl)aziridines under the same reaction conditions. A thorough insight into the reaction mechanism was provided by both experimental study and theoretical rationalization.     

Reaction of azole condensed quinoxaline N-oxides with acetic anhydride

The reaction of 7-chlorotetrazolo[1,5-α]quinoxaline 5-oxide 6a with acetic anhydride gave 7-chloro-5-(7-chlorotetrazolo[1,5-α]quinoxalin-4-yl)-4,5-dihydro-4-oxotetrazolo[1,5-α]quinoxaline 7a , while the reaction of 7-chloro-1,2,4-triazolo[4,3-α]quinoxaline 5-oxide 6b with acetic anhydride afforded 7-chloro-5-(7-chloro-1,2,4-triazolo[4,3-α]quinoxalin-4-yl)-4,5-dihydro-4-oxo-1,2,4-triazolo[4,3-α]quinoxaline 7b and 7-chloro-4,5-dihydro-4-oxo-1,2,4-triazolo[4,3-α]quinoxaline 8b . The reaction of compound 6a or 6b with acetic anhydride/acetic acid provided 7-chloro-4,5-dihydro-4-oxo-tetrazolo[1,5-α]quinoxaline 8a or compound 8b , respectively.     

Synthesis of Some Bromomethyl‐ and (4‐Bromomethyl)phenyl‐Derivatives of 1,4,8,11 Tetraaza[14] annulene and Their Corresponding Sulfanylmethylene‐Derivatives Using 3‐Substituted Trimethinium Salts

Four new 6,13‐di(bromomethyl)‐ and di[(4‐bromomethyl)phenyl]1,4,8,11‐tetraaza[14]annulene derivatives C , D , E , F were synthesized using the condensation reaction of the correspondingly substituted vinamidinium salts with aromatic amines in acetonitrile/acetic acid. The reaction of these annulenes with thiourea leads to the corresponding thiol derivatives G and H . The UV/vis spectral behavior of compounds C , D , E , F , G , H was examined in DMSO. Elemental analysis, IR, ¹H‐NMR, ¹³C‐NMR, and mass spectral data confirm the molecular structure of the newly synthesized compounds.     

Synthesis of Novel Drug‐Like Small Molecules Based on Quinoxaline Containing Amino Substitution at C‐2

A series of novel “drug‐like” small molecules based on quinoxaline containing amino substitution at C‐2 were synthesized. All these molecules were prepared either via the reaction of 2‐phenyl‐3‐(piperazin‐1‐yl)quinoxaline with acyl bromides or benzyl bromides or various carboxylic acids or via the reaction of 2‐chloro‐3‐phenylquinoxaline with various amines. The structures of these novel compounds were confirmed by spectral analysis. The strategy used is simple and efficient and afforded good yields of quinoxaline derivatives.     

Utility of the Pfitzinger Reaction in the Synthesis of Novel Quinoline Derivatives and Related Heterocycles

2‐(2‐Amino‐3,5‐dinitrophenyl)‐2‐oxoacetic acid ( 2 ) was obtained from hydrolysis of 5,7‐dinitroisatin ( 1 ) in alkaline media. A novel quinoxaline derivative ( 3 ) was synthesized from the reaction of the same compound ( 1 ) with o‐phenylenediamine. Reacting 2 with ethyl 3‐oxo‐3‐phenylpropanoate yields 6,8‐dinitro‐2‐phenylquinoline‐3,4‐dicarboxylic acid ( 4 ). Then, 4 was converted into new quinoline‐diacylchloride, quinoline‐ester, quinoline‐dicarboxamide, pyridazine, and pyrroledione derivatives ( 5 , 6a , 6b , 6c , 6d , 7a , 7b , 7c , 7d , 8 , 9 , 10a , 10b , 10c , 10d , 11a , 11b , 12 ) with SOCl₂, alcohols, amines, and hydrazines, respectively. The structures of synthesized compounds were clarified by ¹H NMR, ¹³C NMR, IR, mass and elemental analysis methods.     

Intramolecular 1,3-dipolar cycloadditions of dihydroimidazolium ylides: synthesis of pyrrolo[1,2,3-de]quinoxalines and imidazo[1,2-a]indoles

N-Alkylation of 4,5-dihydroimidazoles with alkene-containing bromomethyl ketones and treatment of the so-formed 4,5-dihydroimidazolium ions with DBU gives rise to an intramolecular 1,3-dipolar cycloaddition reaction that affords (via a reaction cascade involving eliminative ring-opening, recyclisation and prototropic tautomerism) unexpected hexahydropyrrolo[1,2,3-de]quinoxaline products. Steric bulk in both the dihydroimidazole and the dipolarophile allows isolation of an imidazo[1,2-a]indole, the initial product of cycloaddition. When the bromomethyl ketone contains no other functionality, or when cycloaddition is inhibited due to steric constraints, the dihydroimidazolium ion undergoes ring-opening hydrolysis followed by recyclization of the exposed amino ketone to afford either 3-alkyl-1-formylpiperazine-2-ones or 3-aryl-1-formyl-1,4,5,6-tetrahydropyrazines.     

Synthesis of 6‐Aminopropyl‐6H‐indolo[2,3‐b]quinoxaline Derivatives

A series of 6‐(3‐aminopropyl)‐6H‐indolo[2,3‐b]quinoxalines were synthesized with high yields by the reaction of 6‐(3‐chloropropyl)‐6H‐indolo[2,3‐b]quinoxaline and corresponding amines in presence of tetrabutylammonium iodide in boiling toluene or dimethylformamide at room temperature. It was found that boiling of 6‐(3‐chloropropyl)‐6H‐indolo[2,3‐b]quinoxaline in acetone with sodium iodide or in acetic acid lead to intramolecular cyclization product.     

7-氯-[1，2，3，4]-四氢吩嗪-[2，3]-并富勒烯[60]的合成

60富勒烯及其衍生物因其结构的特殊性,在有机超导、分子磁性、有机发光材料、分子器件、非线性光学活性、能量代谢和生物活性等[1]方面表现出独特的性能和潜在的应用前景,是非常活跃的研究领域之一.     

Pyrrolo-annelated tetrathiafulvalenes: the parent systems

The synthesis of a number pyrrolo-annelated tetrathiafulvalenes, including the parent bis(pyrrolo[3,4-d])tetrathiafulvalene (7) is decribed. Starting from readily available 4,5-bis(bromomethyl)-1, 3-dithiole-2-thione (14) and sodium tosylamide, the parent 7 and the asymmetric monopyrrolo tetrathiafulvalenes 23a,b were prepared in good yields via a nonclassical and simple pyrrole synthesis. Furthermore, a series of asymmetrical N-alkylated monopyrrolo/monodihydropyrrolotetrathiafulvalenes was prepared starting from primary amines and 14. A detailed study of the fundamental redox behavior of this class of heterocycles is reported. NMR spectroscopy, cyclic voltammetry, and PM3 MO calculations revealed that the pyrrolo-annelated tetrathiafulvalenes have highly extended pi-surfaces. The X-ray crystallographic analyses of the monopyrrolo tetrathiafulvalenes 22b and 24b, together with preliminary formation of a charge-transfer complex between the parent donor 7 and TCNQ, are also reported.     

Synthesis of benzo[f]isoindole-4,9-diones

A synthesis of benzo[f]isoindole-4,9-diones 1 is presented starting from the reaction of 2,3-bis(bromomethyl)-1,4-dimethoxynaphthalene 15 with primary amines affording 2,3-bis(aminomethyl)-1,4-dimethoxynaphthalenes 14, which could be converted by CAN-mediated oxidation in one step to benzo[f]isoindole-4,9-diones 1. An alternative synthesis of benzo[f]isoindole-4,9-diones 1 starts from 2,3-bis(bromomethyl)-1,4-naphthoquinone 9 via 2,3-dihydrobenzo[f]isoindoles 10 which spontaneously oxidize.     

Rapid and efficient synthesis of 2-substituted-tetrahydropyrido[3,4-b]quinoxalines using TDAE strategy

We report herein an original and rapid synthesis of substituted 2-tosyl-1,2,3,4-tetrahydropyrido[3,4-b]quinoxaline derivatives by TDAE strategy from 2,3-bis(bromomethyl)quinoxaline and N-(toluenesulfonyl)benzylimines.     

Synthesis of 4H-1,3,4-oxadiazino[5,6-b]quinoxalines from 2-substituted quinoxaline 4-oxides

The reaction of 6-chloro-2-(1-methylhydrazino)quinoxaline 4-oxide 8 with acetic anhydride resulted in the intramolecular cyclization to give 8-chloro-2,4-dimethyl-4H-1,3,4-oxadiazino[5,6-b]quinoxaline 7a , while the reaction of compound 8 with acetic anhydride/pyridine or acetic anhydride/acetic acid afforded 3-(2,2-diacetyl-1-memymydrazmo)-7-chloro-2-oxo-1,2-dihydroquinoxaline 9 , effecting no intramolecular cyclization. The reaction of 2-(2-acetyl-1-methylhydrazino)-6-chloroquinoxaline 4-oxide 10a or 6-chloro-2-(1-methyl-2-trifluoroacetylhydrazino)quinoxaline 4-oxide 10b with phosphoryl chloride provided compound 7a or 8-chloro-4-memyl-2-trifluoromethyl-4H-1,3,4-oxadiazino[5,6-b]quinoxaline 7b , respectively. The reaction of compound 7b with phosphorus pentasulfide gave 7-chloro-3-(1-methyl-2-trifluoroacetylhydrazino)-2-thioxo-1,2-dihydroquinoxaline 11 , whose dehydration with sulfuric acid in acetic acid afforded 8-chloro-4-methyl-2-trifluoromemyl-4H-1,3,4-thiadiazino[5,6-b]quinoxaline 12 .     

Synthesis, spectra, and theoretical investigations of the triarylamines based on 6H-indolo[2,3-b]quinoxaline

Triarylamines containing a 6H-indolo[2,3-b]quinoxaline core and aromatic units such as phenyl, naphthyl, pyrene, anthracene, or fluorene have been synthesized by employing palladium-catalyzed C-N and C-C coupling reactions and characterized by optical absorption and emission spectra, electrochemical behavior, and thermal studies. Even though the electronic absorption spectra of the compounds were influenced by the nature of the peripheral amines, the emission spectra indicated close similarity for the excited states in these compounds. For the derivatives in which the amines were directly anchored on the 6H-indolo[2,3-b]quinoxaline nucleus, the emission appeared to be dominated by the state localized on the 6H-indolo[2,3-b]quinoxaline chromophore, while in the compounds containing the extended conjugation the fluorescence originated from the polyaromatic linker. The compounds displayed green or yellow emission depending on the nature of the amine segment. All of the dyes displayed one-electron quasi-reversible oxidation couple in the cyclic voltammograms, which is attributable to the oxidation of the peripheral amines at the 6H-indolo[2,3-b]quinoxaline core. An additional one-electron oxidation process observable at the high positive potentials for the compounds 7 and 8 probably arises from the oxidation of the arylthiophene segment. The enhanced thermal stability and relatively higher glass transition temperatures observed for these compounds were attributed to the presence of dipolar 6H-indolo[2,3-b]quinoxaline segment. The origin of the optical spectra and the trends observed therein were rationalized using TDDFT simulations.     

A convenient synthesis of novel pyridazino[3,4-b]quinoxaline and pyrazolo[3,4-b]quinoxaline utilizing 1,3-dipolar cycloaddition reaction

The reaction of 2,6-dichloroquinoxaline 4-oxide 4 with methylhydrazine gave 6-chloro-2-(1-methylhydrazino)quinoxaline 4-oxide 5, whose reaction with dimethyl acetylenedicarboxylate or 2-chloroacrylonitrile resulted in the 1,3-dipolar cycloaddition reaction to afford 7-chloro-3,4-bismethoxycarbonyl-1-methyl-1,2-dihydropyridazino[3,4-b]quinoxaline 6 or 6-chloro-3-hydroxymethylene-1-methyl-2,3-dihydro-1H-pyrazolo[3,4-b] quinoxaline hydrochloride 7, respectively.     

2-Iodo benzoic acid: An unconventional precursor for the one pot multi-component synthesis of quinoxaline using organo Cu (II) catalyst

This is the first reported, unconventional, efficient strategy for the synthesis of quinoxaline from 2 to iodo benzoic acid and sodium azide in presence of organo Cu (II) catalyst. Herein, a very simple, versatile one pot multi-component protocol for the synthesis of biologically active compound, quinoxaline has been described via Schmidt reaction and the nucleophilic substitution reaction. The isolated compounds were characterized by 1H NMR, 13C NMR. Our reported organo catalyst was characterized by single crystal XRD, SEM.     

Reaction of enol type acyl cyanide with o-aminophenol

The reaction of 7-chloro-4-(2-cyano-2-hydroxyvinyl)tetrazolo[1,5-a]quinoxaline 2a with o-aminophenol gave 7-chloro-4-(b-hydroxyphenylcarbamoylmethylene)4,5-dihydrotetrazolo[1,5-a]quinoxaline 4 , while the reaction of compound 2a with o-aminophenol hydrochloride afforded 4-[2-(2-benzoxazolyl)-2-hydroxyvinyl]-7-chlorotetrazolo[1,5-a]quinoxaline 5 , whose acetylation provided 4-[2-acetoxy-2-(2-benzoxazolyl)vinyl]-7-chlorotetrazolo[1,5-a]quinoxaline 6 . The behavior in a deuteriodimethyl sulfoxide or deuteriotrifluoroacetic acid solution is described for compounds 4–6 .