Synthesis of 1-halophenyl 4-(2-imidazolyl)-1-butanones and 5-(2-imidazolyl)-1-pentanones and their ketalization with glycerol

An alternate synthesis of 1-(2,4-dichlorophenyl)-4-(2-imidazolyl)-1-butanones 5d is presented after 1-[(dimethylamino)methyl- and 1-methyl]-2-lithioimidazole failed to be substituted satisfactorily by 2-(2,4-dichlorophenyl)-2-(3-iodopropyl)-1,3-dioxolane ( 3b ). The Pinner addition of ethanol to 2-(2,4-dichlorophenyl)-2-(3-cyanopropyl)-1,3-dioxolane yielded the corresponding imidate which was reacted with 1-amino-2,2-dimethoxyethane to form an amidine. Hot dilute hydrochloric acid converted this ami-dine to the 2-imidazolyl ketone 5b . Syntheses of homologous 1-(4-chloro- and 2,4-dichlorophenyl)-4-(2-imidazolyl)-1-pentanones 20 are described. Ketalizations of 5 and 20 with glycerol formed imidazolyl 1,3-dioxolanyl alcohols. Selective N- and O-alkylations of some of these imidazolyl alcohols are described.     

Polymeric catalysis: Imidazoles grafted onto poly(vinylamine). I. Synthesis and grafting of imidazolylalkanoic acids

Some ω-(1-imidazolyl) and ω-[4(5)-imidazolyl]alkanoic acids were synthesized and grafted onto poly(vinylamine) with an amide bond. These water-soluble grafts were used to study the kinetics of the esterolysis of activated phenyl esters. The 1-substituted imidazoles were prepared by the reaction of the sodium salt of imidazole with the ethyl ω-bromoalkanoates. The 4(5)-substituted imidazoles were prepared from urocanic acid or 4(5)-hydroxymethylimidazole. The ω-(1-imidazolyl)alkanoic acids were grafted onto poly(vinylamine) via their acyl–guanidine derivatives; the 3-[4(5)-imidazolyl]propanoic acid was grafted with a water-soluble carbodiimide.     

The Reaction of 2-Aminoethyl- and 3-Aminopropyl-substituted Heterocycles with 2-Formyl-1,3-cyclanediones and 4-Oxo-3,1-benzoxazines

The reaction of 2-formyl-1,3-cyclohexanedione, its 5,5-dimethyl, 5-phenyl and 5-(2-furyl) derivatives and of 2-formyl-1,3-indanedione and dehydroacetic acid with histamine, 3-(1-imidazolyl)propylamine, 3-(4-morpholyl)propylamine, 3-(2-pyrrolidon-1-yl)propylamine, 2-(1-piperazinyl)ethylamine, tryptamine, and 2-(aminomethyl)pyridine gave fifteen 2-aminomethylene derivatives. The reaction of these amines with 2-methyl-4-oxo-3,1-benzoxazine gave the 3-substituted 2-methyl-4(3H)-quinazolinones and with 4-oxo-2-phenyl-3,1-benzoxazine the monosubstituted N-benzoylanthranilic acid amides.     

2-甲基-7-[ω -(1-咪唑基)-烷氧基]异黄酮衍生物的全合成及其抗氧化活性

以取代苯乙酸和间苯二酚为起始原料, 经5步合成了10种新的咪唑类异黄酮衍生物. 利用1H NMR, 13C NMR和元素分析等对目标化合物进行了表征. 对10种目标化合物的抗氧化活性进行了初步研究, 其中2-甲基-4'-羟基-7-[3-(1-咪唑基)丙氧基]异黄酮具有较强的抗氧化活性.     

Synthesis,structure elucidation and chemotherapeutic activity of 6-substituted 1-ethyl-1,4-dihydro-7-[(1-imidazolyl)phenylmethyl]- 4-oxo-3-quinolinecarboxylic acids

The synthesis, structure elucidation and chemotherapeutic activity of novel 3-quinolinecarboxylic acid derivatives are reported. These derivatives are characterized by a group (1-imidazolyl)phenylmethyl attached to the 7-position and chloro 10a , fluoro 10b or methoxy 10c appended to the 6-position.     

Synthesis of aryl 2-(2-imidazolyl)ethyl ketones

The Claisen-Schmidt condensation of 1-(triphenylmethyl)-2-imidazolecarboxaldehyde with acetophenones yielded 1-aryl-3-[1-(triphenylmethyl)-2-imidazolyl]propen-1-ones 7 . Selective catalytic hydrogenation over platinum of 7 furnished 1-aryl-3-(2-imidazolyl)-1-propanones 8 . An alternate synthesis of 8 started with sodium borohydride reduction of 7 to give allylic alcohols, 1-aryl-3-[1-(triphenylmethyl)-2-imidazolyl]-2-propen-1-ols 10 , which were rearranged by hot aqueous sodium to 8 . Acid hydrolysis of 8 provided the title compounds and triphenylmethanol.     

双分子维生素B_(12)模型分子的合成及表征

维生素B_(12)经醇解得到的七甲基钴啉酯1作为起始原料，经酸性水解分别得 到b,c,d,e,f-单酸钴啉酯2b～2f, 2b～2f与3-咪唑基丙胺盐酸盐反应合成了相应的 酰胺钴啉酯衍生物3b～3f, 3b～3f在乙酸的作用下合成了双分子络合维生素B_(12) 模型化合物双-单腈六甲基-N-（3-咪唑基）丙酰胺钴啉酯高氯酸盐5b～5f，并对其 化学结构进行了表征。     

Potential histidine decarboxylase inhibitors. II. 3-(4-Imidazolyl)-2-pyridine and piperidinecarboxylates

The synthesis of methyl 3-(4-imidazolyl)-2-pyridine ( 12 ) and piperidineearboxylates ( 13 ) is described. Hydrolysates of these esters were found to be devoid of inhibitory activity against histidine decarboxylase. 3-Bromoacetyl-2-pieoline ( 2 ) could be converted to 3-(4-imidazolyl)-2-picoline ( 6 ) by two different routes. Treatment of 6 with peroxide and acetic anhydride, followed by transesterification yielded the 2-hydroxymcthyl pyridine ( 9 ). Oxidation of 9 followed by esterification gave the imidazole pyridine acid ester ( 12 ) which after hydrogenation afforded the imidazolylpiperidine ester ( 13 ).     

Reactivities of 3-(1-Azolyl)-2-alken-1-ones and the related compounds with pyrrolidine

From the rate constants of the reaction with pyrrolidine, the reactivities of 3-(1-azolyl)-2-alken-1-ones with nucleophiles were evaluated to be rather high. Especially the reactivities of the quaternary salts of 3-(1-imidazolyl)-2-alken-1-ones were nearly equal to those of 3-chloro-2-alken-1-ones. In conclusion, 3-(1-imidazolyl)-2-alken-1-ones satisfied the practical requirements for the starting materials of the synthesis of 3-hetero-substituted 2-alken-1-ones.     

Ketalizations of aryl ω-(2-imidazolyl)alkyl ketones by glycerol and 3-mercapto-1,2-propanediol. synthesis and characterization of cis- and trans-{2-aryl-2-[ω-(2-imidazolyl)alkyl](1,3-dioxolan-4-yl and 1,3-oxathiolan-5-yl)}methanols

Aryl 2-[(2-imidazolyl)ethyl or 3-(2-imidazolyl)propyl]ketones were ketalized by glycerol or 3-mercapto-1,2-propanediol in boiling benzene in the presence of 4-toluenesulfonic acid to provide the title compounds. The aryl substituents are 4-chloro-, 4-bromo-, 4-fluoro-, or 2,4-dichlorophenyl. While aryl (2-imidazolyl)methyl ketones condensed with glycerol to form cis- and trans-{2-aryl-2-[(2-imidazolyl)methyl]-4-(hydroxymethyl)}-1,3-dioxolanes, related condensations with 3-mercapto-1,2-propanediol, under similar, or even more stringent reaction conditions, produced no 1,3-oxathiolane analogs, with the starting ketones being recovered. Separation and structure determination of these racemic cis and trans isomeric products are described. The structure of these stereoisomers was established by means of ¹H and ¹³C nmr correlation and nOe experiments. Selective methylation of the N-unsubstituted 2-imidazolyl alcohols with one equivalent sodium hydride and methyl iodide provided the corresponding N-methyl alcohols in excellent yields. With excess benzoyl chloride, N-unsubstituted 2-imidazolyl alcohols were initially converted to O, N-dibenzoates from which the N-benzoyl group was easily cleaved by ammonium hydroxide in ethanol to provide benzoate esters.     

Nitroimidazoles X . Syntheses of substituted 2-(1-methyl-5-nitro-2-imidazolyl)quinolines

Reduction of substituted-2-nitrobenzaldehyde (1) afforded substituted-2-aminobenzaldehyde (2) . Reaction of compound 2 with 2-acetyl-1-methyl-5-nitroimidazole (3) under basic conditions afforded substituted 2-(1-methyl-5-nitro-2-imidazolyl)quinolines 4 . Reaction of compound 4 (R = X) with hydrogen peroxide in acetic acid afforded compound 5 which was transformed to compound 6 with phosphorus oxychloride.     

Utilization of 2-alkenoic acids for biosynthesis of medium-chain-length polyhydroxyalkanoates in metabolically engineered Escherichia coli to construct a novel chemical recycling system

This study describes the biosynthesis and thermal degradation of medium-chain-length polyhydroxyalkanoate (PHA), focusing on 2-alkenoic acids as a recyclable carbon source. Using metabolically engineered Escherichia coli, PHA consisting of 3-hydroxydecanoate (3HD) was synthesized from 2-decenoic acid. Solvent cast film of poly(3HD) [P(3HD)] was transparent and showed thermal property similar to that of polycaprolactone. In addition, the use of various 2-alkenoic acids (C6-C12) resulted in production of PHAs with over 95 mol% of the corresponding single monomer units. The pyrolysis product of P(3HD) was dominantly 2-decenoic acid used for the P(3HD) biosynthesis. This demonstrates the feasibility of PHA recycling via 2-alkenoic acids, which act as pyrolysis products and raw materials for PHA biosynthesis.     

Synthesis of aryl ω-(1-methyl-5-imidazolyl and 1H-5-tetrazolyl)alkyl ketones

Successful syntheses of 2,4-dichlorophenyl 2-(1-methyl-5-imidazolyl)ethyl and 2,4-dichlorophenyl 3-(1-methyl-5-imidazolyl)propyl ketones are described. In addition, syntheses of 2,4-dichlorophenyl and 4-chlorophenyl 3-(1-methyl-1H-5-tetrazolyl)propyl ketones are reported.     

A novel regio-and stereo-specific hydrohalogenation reaction of 2-alkynoic acids and their derivatives

The nucleophilic hydrohalogenation of 2-alkynoic acids anti their derivatives byheating with lithium halides iu HOAc afforded the thermodynamically unfavorable 3-halo-2 (Z)-alkenoic acids and their derivatives stereospecifically     

Synthesis of aryl 3-(2-imidazolyl)propyl ketones

The approach to the title compounds was via lithiation-substitution of N-methyl or N-(triphenylmethyl)-imidazole by some iodo ketals. 4-Chloro-4′-halobutyrophenones (halo = F, Cl, Br) were converted by sodium iodide to the corresponding aliphatic iodides which were subsequently ketalized with ethylene glycol to provide the corresponding iodo ketals. Lithiation of either 1-methyl- or 1-(triphenylmethyl)imid-azole with N-butyllithium generated the corresponding 2-lithioimidazoles, in situ, which were then reacted with these iodo ketals to form the corresponding C-2 substituted imidazoles. Dilute aqueous acid hydrolysis released the ketone from the ketal. For N-triphenylmethyl protected imidazoles, the triphenylmethyl group was also hydrolyzed to give triphenylmethanol and 3-(2-imidazolyl)propyl 4-haloaryl ketones. These N-unsubstituted imidazolyl ketones can be alkylated independently with triphenylmethyl chloride to form the corresponding N-triphenylmethyl imidazole derivatives.     

The reaction of 3-(1-imidazolyl)-2-alken-1-ones with nucleophiles

Generally 3-hetero-substituted 2-alken-1-ones were prepared from 1,3-alkanediones, 3-chloro-2-alken-1-ones, or conjugated ynones. The preparation of 3-hetero-substituted 2-alken-1-ones was subjected to some limitations by these methods. By the reaction of 3-(1-imidazolyl)-2-alken-1-ones (I) and 3-(3-oxo-1-alkenyl)-1-methylimidazolium iodides (II) with nucleophiles, 3-hetero-substituted 2-alken-1-ones could be obtained regioselectively in good yield under mild conditions. These results suggested that compounds I and II were concluded to be useful intermediates for the organic synthesis.     

Modified knoevenagel condensations. Synthesis of (E)-3-alkenoic acids.

Condensation of aliphatic aldehydes with a three molar excess of malonic acid and 0.001 mole of piperidinium acetate in refluxing xylene, with continuous removal of the water formed, gave almost exclusively (E)-3-alkenoic acids, in good yield (60–85%) and of high stereochemical purity (95–99%).     

Synthesis of Adamantane Derivatives. XVIII. On the Bromination of 1- and 3-Homoadamantanecarboxylic Acids. an Improved Synthesis of L-Bromomethyladamantane-3-Carboxylic Acid and Some Derivatives Thereof

Although the ionic bromination of adamantane and its derivatives has been well established,² direct bromination of homoadamantane derivatives seems not to be strdied extensively.³ We wish to report the bromination of 1- (IIb) and 3-homoadaman-tanecarboxy acid (IIa), which provided an improved preparative method for 1-bromomethy ladamantane-3-carboxylic acid (III).     

Reactions of n,n'-thiocarbonyl diimidazole with 1,3-dipolar agents : The synthesis of 5-substituted-2-(1-imidazolyl)-1,3,4-thiadiazoles and 5-( 1-imidazolyl)-1,2,3,4-thiatriazole

By the reaction of N,N'-thiocarbonyl diimidazole with diazomethane, diazoacetic ethylester, phenyl diazoketone and 4-nitrophenyl diazomethyl ketone catalysed by tertiary amines, 5-substituted 2-(1-imidazolyl)-1,3,4-thiadiazoles were prepared, by the action of N,N'-thiocarbonyl diimidazole with azoimide, trimethylsilyl azide and thiophosgene 5-(1-imidazolyl)-1,2,3,4-thiatriazole was synthesised. The structure of compounds prepared was proved by ¹H NMR and mass spectrometry.     

Darstellung,Eigenschaften und Kristallstruktur von [2-(1′-methyl-4-imidazolyl)phenyl-1-C,3′-N]acetylacetonatopalladium(II)

Synthesis, Properties, and Structure of [2-(1′-methyl-4-imidazolyl)phenyl-1-C,3′-N]-palladium(II) Acetylacetonate The reaction of Di-μ-chloro-bis[2-(1′-methyl-4-imidazolyl)phenyl-1-C,3′-N]palladium(II) with Thallium(I) acetylacetonate yields [2-(1′-methyl-4-imidazolyl)phenyl-1-C,3′-N]palladium(II) acetylacetonate. The complex crystallizes monoclinic in the space group P2₁/n with the lattice constants a = 1302.4(3), b = 836.0(2), c = 1341.3(3) pm, β = 93.69(3)°. Pd has a squareplanar coordination by two O atoms of acetylacetonate, the N atom of the imidazole ring, and the C atom of the phenyl group. I.r., n.m.r., and mass spectra are reported.