Synthesis and antimicrobial screening of heterocycles derived from 3-[(4-benzyloxy)phenyl]-1- (3-chlorophenyl)prop-2-ene-1-one

The kinetics of reaction of substituted O-benzoylbenzamidoximes with sodium methoxide in methanol were studied at 25 °C. The only reaction products are substituted benzamidoximes and methyl benzoates. The slope of the dependence of rate constant on sodium methoxide concentration gradually increases, but in the presence of C18 crown ether the dependence becomes linear and the rate constant is lower than in the absence of the crown ether, which means that the reaction is catalysed by sodium cation. The rate constants of reactions with the ion pair and with methoxide ion were determined with the presumption that the rate-limited step of the catalysed reaction is the reaction of substituted O-benzoylamidoximes with the ion pair of sodium methoxide. The rate constants of the reaction with the ion pair are about 20 times higher than those of the non-catalysed process. The slopes of the dependence of log k of the non-catalysed and catalysed reactions on the pKa of substituted benzamidoximes are 1.05 and 0.94, respectively. These high values indicate the rate-limiting step involving the splitting off of substituted benzamidoxime from the tetrahedral intermediate. On the basis of the relatively high ρ constant of methanolysis at the benzoyl group substituted derivatives (2.17 and 1.98 for the non-catalysed and catalysed reactions, respectively), it can be presumed that the transition state structure will be close to the tetrahedral intermediate. Copyright © 1999 John Wiley & Sons, Ltd.

Sodium methoxide is used as a reagent or a catalyst in many industrial processes such as, for example, pharmaceuticals and biodiesel syntheses. This work presents a new and selective quantitative analytical thermometric method for sodium methoxide determination in methanol solutions in the presence of hydroxide ions. For comparative purposes with the Karl-Fischer procedure, these two methods were applied to four different solutions of sodium methoxide in methanol, including in presence of sodium hydroxide, and the results were compared statistically showing total agreement.

A simple and selective spectrophotometric method has been developed for the first time for the determination of sodium methoxide in methanol solution in the presence of sodium hydroxide. The developed method involves the formation of a pink species by the reaction between sodium methoxide and α-santonin. The pink compound formed shows absorbance maximum at 513 nm. N, N-Dimethylformamide and methanol were used as solvents, and the reaction was performed at different temperatures and 25 °C was selected for further experiments. The pink compound formed was dried and then was studied using FTIR and mass spectrometry. The calibration curve was constructed from 0.10 to 0.30% (m/v) sodium methoxide in methanol, and the standard deviation is 0.010%. Similarly, the relative standard deviations of 28%, 26%, and 24% solutions of sodium methoxide were obtained in the range of 0.4 to 1.9%. The correlation coefficient of the analytical curve r = 0.9997; the limit of detection, LOD, is ca. 1.1 × 10-3 % w/w; and the limit of quantification, LOQ, is ca. 3.2 × 10-3 % w/w. The results of analysis were validated statistically.

The reaction of 1,2,3,4,7-syn-pentachloronorborna-2,5-diene with ethoxide ions results in a 3:5 mixture of products derived from replacement of a vinylic chlorine atom and from addition to the unsubstituted double bond. The 7-anti-isomer and 1,2,3,4-tetrachloronorborna-2,5-diene afford only products of reaction at the chlorine-substituted double bond. The 5-phenyl derivatives of these dienes react with sodium methoxide in methanol to afford the products of the addition of methanol to the phenyl-substituted double bond. Reaction occurs at both double bonds when hexachloronorbornadiene is treated with sodium methanethiolate in ethanol. 5-Methylhexachloronorbornadiene is isomerised to hexachloromethylenenorbornene on treatment with sodium methoxide in methanol; with dimethylformamide as solvent further reaction occurs at the chlorine-substituted double bond of the isomerised diene. The results are interpreted in terms of a series of finely balanced factors controlling product formation.

ChemInformVolume 19, Issue 13 Preparative Organic Chemistry ChemInform Abstract: Reactions of N-Chlorobenzylalkylamines with Sodium Methoxide in Methanol. Steric Effects in Elimination Reactions. B. R. CHO, B. R. CHO Dep. Chem., Korea Univ., Seoul, KoreaSearch for more papers by this authorJ. H. MAENG, J. H. MAENG Dep. Chem., Korea Univ., Seoul, KoreaSearch for more papers by this authorJ. C. YOON, J. C. YOON Dep. Chem., Korea Univ., Seoul, KoreaSearch for more papers by this authorT. R. KIM, T. R. KIM Dep. Chem., Korea Univ., Seoul, KoreaSearch for more papers by this author B. R. CHO, B. R. CHO Dep. Chem., Korea Univ., Seoul, KoreaSearch for more papers by this authorJ. H. MAENG, J. H. MAENG Dep. Chem., Korea Univ., Seoul, KoreaSearch for more papers by this authorJ. C. YOON, J. C. YOON Dep. Chem., Korea Univ., Seoul, KoreaSearch for more papers by this authorT. R. KIM, T. R. KIM Dep. Chem., Korea Univ., Seoul, KoreaSearch for more papers by this author First published: March 29, 1988 https://doi.org/10.1002/chin.198813080AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume19, Issue13March 29, 1988 RelatedInformation

The reaction of 3‐bromo‐2‐iodothiophene with sodium methoxide in methanol, pyridine or hexamethylphosphoric triamide and the same reaction of 4‐bromo‐2‐iodo‐ and 4‐bromo‐3‐iodo‐thiophene in pyridine led to a halogen‐dance, giving the same mixture of 3‐bromothiophene, bromo‐iodothiophenes, diiodo‐bromothiophenes and triiodo‐bromothiophenes. The reaction of all three isomeric bromo‐iodothiophenes with sodium methoxide in methanol in the presence of cupric oxide gave 4‐bromo‐2‐methoxythiophene.

A method for unmounting entire resin-embedded samples for SEM observation is described. This technique is particularly useful when correlation of TEM and SEM images is desired for material that is no longer available for conventional SEM preparative procedures. Sample embedded in a variety of epoxy-type resins were trimmed of excess resin and placed in a concentrated solution of sodium methoxide. After complete dissolution of the resin, the tissue was washed in a graded series of sodium methoxide in methanol--benzene, transferred to acetone, critical point dried, mounted on stubs, and coated with gold-palladium. Upon viewing in the SEM, the tissue sample showed remarkable preservation of detail at relatively high magnifications.

The 1:1 interactions of picramide, N-substituted picramides, and NN-dimethylpicramide with sodium methoxide in methanol have been investigated by stopped-flow and T-jump spectrophotometry. Picramide and its N-substituted derivatives give rise to a very rapid process which is attributed to proton transfer to give the conjugate base, and to a slower process (measurable by stopped-flow) attributed to methoxide addition at the unsubstituted 3-position. The variation of rate and equilibrium constants with substituent are discussed.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTKinetics, products, and mechanisms of reaction of tert-butyl chloride with sodium methoxide in methanol and dimethyl sulfoxide/methanol solventsJoseph F. Bunnett and Cyril A. MigdalCite this: J. Org. Chem. 1989, 54, 13, 3037–3041Publication Date (Print):June 1, 1989Publication History Published online1 May 2002Published inissue 1 June 1989https://doi.org/10.1021/jo00274a014RIGHTS & PERMISSIONSArticle Views542Altmetric-Citations2LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (661 KB) Get e-Alerts Get e-Alerts

Regioselective hydroborations of methylvinylchlorosilanes

1,6:2,3-Dianhydro-4-deoxy-β-DL-ribo-hexopyranose (1), a product obtained from acrolein dimer (3,4-dihydro-2H-pyran-2-carboxaldehyde), has been converted to 1,6-anhydro-4-deoxy-3-O-methyl-β-DL-xylo-hexopyranose (2) by reaction with acidic methanol or sodium methoxide in methanol. The structure and conformation of 2 have been confirmed by nuclear magnetic resonance spectroscopy. The reaction of 2 with methanol in the presence of Amberlite IR-120 (H+) gave a 2:1 mixture of the α and β isomers of methyl 4-deoxy-3-O-methyl-DL-xylo-hexopyranoside (3) from which the individual α and β isomers of the di-p-nitrobenzoates could be obtained as crystalline solids. Conversion of 3 to the corresponding di-O-p-toluenesulfonates 4, followed by selective reduction of these diesters with LiAlH4 gave a mixture of the α and β isomers of methyl 4,6-dideoxy-3-O-methyl-2-O-p-toluenesulfonyl-DL-xylo-hexopyranoside (5). Reaction of 5 with sodium methoxide in methanol gave a 2:1 mixture of the α and β isomers of methyl 4,6-dideoxy-3-O-methyl-DL-xylo-hexopyranoside (6) (methyl DL-chalcoside) from which only the α isomer could be separated in pure form by column chromatography or gas–liquid chromatography. The α isomer, 6-α, upon acid-catalyzed hydrolysis in aqueous dioxane, gave a mixture of the α and β isomers of 4,6-dideoxy-3-O-methyl-DL-xylo-hexopy-ranose (DL-chalcose) which gave the same nuclear magnetic resonance spectrum in D2O as did authentic D-chalcose. Yields are good to excellent in the various steps from 1 on.

The addition of crown ethers 1,4,7,10,13-pentaoxacyclopentadecane (15C5) and 1,4,7,10,13,16-hexaoxacyclooctadecane (18C6) in quantities equimolar to the base, to β-elimination reactions of 1,1,1-trifluoro-2,2-di(4-nitrophenyl)ethane and 1-fluoro-2,2-di(4-nitrophenyl)ethane promoted by sodium methoxide in methanol, has been investigated. In the E2 reaction of the monofluoro compound, the crown ethers caused no change in the kinetic order and only small changes in the second-order rate constants and activation parameters. The primary deuterium isotope effect was also unaltered by the presence of crown ethers.For the (E1cB)R reaction of the trifluoro compound, no change in kinetic order was found, but slightly larger rate constant changes and an increase in the isotope effect from kH/kD = 1.0 to 1.25 at 25 °C was observed. This is interpreted as an alteration in mechanism from (E1cB)R towards (E1cB)I.

Several crystalline β-D-glycopyranosyl N, N-dialkyldithiocarbamates (sugar=gluco, galacto, xylo or lacto ; alkyl=methyl or ethyl) were synthesized by reaction of sodium N, N-dialkyl-dithiocarbamates with acetylated α-D-glycopyranosyl bromides and sequential deacetylation with methanolic ammonia or sodium methoxide in methanol. Although the glycosyl dithiocarbamates were stable against chilled alkalis and which is a marked difference from glycosyl xanthates or isothiuronium, easily decomposed with mercury salts to form glycosides under the presence of alcohols or phenols. D-Glucopyranosyl N, N-diethyldithiocarbamates having N, N-diethyldithiocarbamoyl radical [chemical formula] at C6 in acetylated D-glucoses or methyl D-glucopyranosides, along with the didithiocarbamate having two carbamoyls at C1 and C6 in acetylated D-glucopyranose, were also synthesized. Reflux of methyl β-D-glucopyranoside-6-deoxy-6-N, N-diethyldithiocarbamate with sodium methoxide in methanol afforded methyl 6-deoxy-6-thio-β-D-glucopyranoside, isolated as its tetraacetate. The method presented a novel synthetic way of thiosugars.

The isomeric 1-, 2-, 3-, and 4-bromo-10-methylacridones undergo a radical chain reduction to 10-methylacridone in the presence of sodium methoxide in methanol. Evidence for the mechanism is presented. In the presence of methanol-free dimethyl sulphoxide, the 1- and 3-bromo-10-methylacridones are cleanly converted by sodium methoxide into the respective methoxy compounds, and the rates have been measured at 40º. In the same solvent, the 2- and 4-bromo isomers are again reduced by sodium methoxide.

5(4H)-Thiazolone derivative 4, obtained from N-dithiocarbobenzoxyglycine (1) and N,N-dimethyl-N′-heteroarylformamidines 3 in acetic anhydride, was rearranged with sodium methoxide in methanol followed by acidification with acetic acid into imidazole-4-carboxylic acid derivatives 5, 6 and 7. These were further converted with methyl iodide into methylthio derivatives 8, with hydrogen peroxide into the corresponding disulphide 9, with hydrazine and amines into hydrazide 10 and amides 11. In the reactions of 4a and 6a with amines in the presence of dichloromethane symetrically disubstituted methanes 14–18 were formed.