Syntheses of quinoline derivatives

In order to study the relationship between structure and biological activity we have synthesized 5-alkoxymethyl- and 5-aryloxymethyl-7-bromo-8-quinolinols.For part II, see [1].     

Syntheses of new benzoxazole derivatives

2‐(Arylidene)cyanomethylbenzoxazoles have been prepared in water from benzoxazole‐2‐ylacetonitriles. Using multi‐component reactions, a variety of heterocycles containing benzoxazole and nitrile functionality has been prepared. J. Heterocyclic Chem., (2011).     

Syntheses of polymerizable hydroquinone derivatives

Several polymerizable hydroquinone derivatives were prepared by the Williamson synthesis. Thus, hydroquinone mono(p-vinylbenzyl) ether (III-1), hydroquinone methyl p-vinylbenzyl ether (III-4), and hydroquinone benzyl p-vinylbenzyl ether (III-5), tert-butylhydroquinone mono(p-vinylbenzyl) ether (III-2), and 2,5-di-tert-butylhydroquinone mono(p-vinylbenzyl) ether (III-3) were synthesized by the reactions of p-chloromethylstyrene with the corresponding hydroquinone derivatives in alcoholic potassium hydroxide or with their potassium salts in dipolar aprotic solvents. All monomers were found to polymerize by free-radical initiation except III-3, which required a cationic initiator.     

Syntheses and reactions of pyrimidine derivatives

By the NMR method, the chemical shifts characterizing the methyl groups in monohydroxymonomethyl derivatives of pyrimidine have been determined. The changes in the chemical shifts and the activities of the methyl groups are symbatic. It has been shown by the NMR method that when 6-hydroxy-2,4-dimethylpyrimidine reacts with benzaldehyde and with p-nitrobenzenediazonium salts reactions take place through the methyl group in position 2. A gradual decrease in the activity of the methyl groups is found in the sequence of 6-hydroxy-, 6-mercapto-, and 6-aminoderivatives of 2,4-dimethylpyrimidine.For part XVII, see [5].     

Syntheses of biologically active sialosylglycerol derivatives

New sialosylglycerol derivatives were synthesized and found to inhibit the phospholipase A2 and C activities.     

Syntheses and biological activity of chalcones-imidazole derivatives

A number of novel 13-membered chalcone-imidazole derivatives were prepared and have been synthesized and characterized by IR, ¹H NMR, ¹³C NMR and elemental analysis, the results conformed well to expected structures. Substituted acetophenones and benzaldehydes were condensed using the Claisen–Schmidt base-catalyzed aldol condensation. Methyl on the aromatic ring of chalcones was brominated by NBS, and then the resulting mixture was reacted with imidazole to get the target compound. Several chalcones showed in vitro antibacterial activity against Gram-bacterial. The results showed that these are potential antibacterial compounds.     

Syntheses in the field of quinoline derivatives

A number of 8-hydroxyquinolin-5-ylmethyl N, N-dialkyldithiocarbamates have been synthesized.For part III, see [3].     

Syntheses of soluble, pi-stacking tetracene derivatives

[reaction: see text] The syntheses of a series of fluorine- and alkyl/alkoxy-functionalized tetracenes are reported. These functional groups are found to improve the solubility in common organic solvents and tune molecular arrangement in solids. The crystal packing, electrochemical behavior, and UV-vis absorbance spectroscopy of these materials are discussed.     

Syntheses of some hexacarboxylic acid derivatives of hexaazatriphenylene

Synthetic methods and product characterizations for the conversions of 1,4,5,8,9,12-hexaazatriphenylene-hexacarboxylic acid to the corresponding triester triacid, triamic acid, triimide, triester triacid chloride, trimethyl triethyl hexaester, trimethyl ester tri(N,N-dimethyrjamide, hexaamide, tri(N,N,-dimethyr)amide triacid, tri(N,N-dimethyl)amide triacid chloride, and trisphthalhydrazide derivatives are described.     

Syntheses of chiral β-amino α-perfluoroalkylpropanol derivatives

Chiral β-amino α-perfluoroalkylpropanol derivatives were synthesized from N-Boc-l-phenylalanine methyl ester by substitution of the methoxy group into the corresponding perfluoroalkyl chain, followed by reduction and deprotection. Among them, a Schiff base prepared by condensation of (2S,3S)-2-amino-3-perfluorooctyl-1-phenylpropan-3-ol, (2S,3S)-1, and 1-naphthaldehyde catalyzed the asymmetric ethyl addition reaction of diethylzinc with the aldehyde to afford the product up to 93% ee.     

含可聚合基团的萘酰亚胺衍生物的合成

以4-溴-1,8-萘酐和4-硝基-1,78-萘酐为起始原料,与各种芳胺经亚胺化,再与脂肪胺经取代反应,最后与丙烯酰氯经酯化得到一系列具有强烈荧光的含丙烯酰氧乙基氨基的1,8-萘酰亚胺衍生物,它们可作为一种聚合荧光色素的单体。     

Syntheses and properties of water-soluble Nile Red derivatives

Nile Red (compound A) fluoresces at about 530 nm with good quantum yields in apolar solvents. In more polar ones its fluorescence emission shows a dramatic, and potentially useful, shift to about 640 nm, but its quantum yield is significantly reduced. Further, Nile Red has a very poor solubility in aqueous media. The hypothesis tested in this paper is that Nile Red derivatives that incorporate water-solubilizing groups will tend to fluoresce with good quantum yields in aqueous media, and in the more useful wavelength range around 640 nm. Thus three Nile Red derivatives, 1-3, were prepared. Compound 1 had three hydroxyl groups more than Nile Red, but was surprisingly insoluble in aqueous media. However, the dicarboxylic acid 2 and carboxylic/sulfonic acid derivative 3 showed excellent water solubilities. Spectral data for 2 and 3 showed that they do indeed fluoresce with good quantum yields in the 640 nm region in aqueous media. These properties of compounds 2 and 3 might be useful in the development of fluorescent probes for biotechnology.