A novel synthesis of 5-aryl-3-cyano-2-pyridones by using vinamidinium salts

A variety of vinamidinium salts were condensated with cyanoacetamide in refluxing methanol that contained sodium methoxide to produce 5-aryl-3-cyano-2-pyridones in good yield. Simple experimental conditions were used to prepare ten different 5-aryl-3- cyano-2-pyridones, four of which are new compounds.C 2009 Song Li. Published by Elsevier B.V. on behalf of Chinese Chemical Society. All rights reserved.

SYNTHSIS OF 5-CYANO-2-(4-n-PENTYL-4-BIPHENYLYL)-PYRIMIDINE

Condensation of substituted diethyl-malonates with phenylamidine hydrochloride give liquid crystals with a pyrimidine ring,which then subjeet graup transformation to give the title compound—5-cyano-2-(4-n-peatyl-4-biphenylyl) pyrimidine in high yield.

A Facile Synthesis of 2-Amino-5-Cyano-4, 6-Disubstitutedpyrimidines under MWI

Microwave Assisted Organic Synthesis (MAOS) is energy efficient and effective tool to speed up the synthesis for drug discovery process. In the present study we report a novel protocol for the rapid, high throughput synthesis of mononuclear 2-amino-5-cyano-4,6-disubstituted pyrimidines, adaptable to parallel synthesis for compound libraries. The overall reaction time in hrs has been reduced to 25 - 50 minutes with improved yields.

Metabolic activity of Streptococcus mutans biofilms and gene expression during exposure to xylitol and sucrose

The objective of the study was to analyse Streptococcus mutans biofilms grown under different dietary conditions by using multifaceted methodological approaches to gain deeper insight into the cariogenic impact of carbohydrates. S. mutans biofilms were generated during a period of 24 h in the following media： Schaedler broth as a control medium containing endogenous glucose, Schaedler broth with an additional 5% sucrose, and Schaedler broth supplemented with 1% xylitol. The confocal laser scanning microscopy（CLSM）-based analyses of the microbial vitality, respiratory activity（5-cyano-2,3-ditolyl tetrazolium chloride, CTC） and production of extracellular polysaccharides（EPS） were performed separately in the inner, middle and outer biofilm layers. In addition to the microbiological sample testing, the glucose/sucrose consumption of the biofilm bacteria was quantified, and the expression of glucosyltransferases and other biofilm-associated genes was investigated. Xylitol exposure did not inhibit the viability of S. mutans biofilms, as monitored by the following experimental parameters： culture growth, vitality, CTC activity and EPS production. However,xylitol exposure caused a difference in gene expression compared to the control. Gtf C was upregulated only in the presence of xylitol.Under xylitol exposure, gtf B was upregulated by a factor of 6, while under sucrose exposure, it was upregulated by a factor of three.Compared with glucose and xylitol, sucrose increased cell vitality in all biofilm layers. In all nutrient media, the intrinsic glucose was almost completely consumed by the cells of the S. mutans biofilm within 24 h. After 24 h of biofilm formation, the multiparametric measurements showed that xylitol in the presence of glucose caused predominantly genotypic differences but did not induce metabolic differences compared to the control. Thus, the availability of dietary carbohydrates in either a pure or combined form seems to affect the cariogenic potential of S. mutans biofilms.

Synthesis of novel benzo[b]pyrimido[4',5':5,4]thieno[2,3-e][1,6]naphthyridine-8-ones via Pictet–Spengler cyclization

An efficient method for the synthesis of novel benzo[b]pyrimido[4′,5′：5,4]thieno[2,3e]-[1,6]naphthyridine-8-one derivatives via Pictet-Spengler cyclization is reported. The reaction of 4-（3-aminopyrimido[4,5-d]thieno-2-yl）quinoline-2-ones, which could be obtained from Thorpe-Ziegler isomerization of 4-bromomethylquinoline-2-ones and 5-cyano-1,6-dihydro-4-methyl-2-phenyl-6-thioxopyrimidine,with aromatic aldehydes in the presence of BF3·OEt2 gives pyrimidothieno[1,6]naphthyridines in good yields.

An environmentally friendly synthesis of 1,4-dihydropyrano[2,3-c]pyrazole derivatives catalyzed by tungstate sulfuric acid

An efficient three-component synthesis of 6-amino-4-aryl-5-cyano-3-metriyl-1-phenyl-1,4-dihydropyrano[2,3-c]pyrazoles via a reaction between 3-methyl-1-phenyl-2-pyrazolin-5-one,aromatic aldehydes and malononitrile using tungstate sulfuric acid as a catalyst was described.Mild conditions,good to excellent yields,easily available catalyst and easy work-up are the key features of this method.