Diethyl Bromomalonate Research Articles

A versatile synthesis of tricyclic analogues of quinolone antibacterial agents: Use of a novel reformatsky reaction

A simple synthesis of tricyclic analogues of the quinolone antibiotics bearing a diverse range of substituents on the aromatic ring is described. The key steps involve unprecedented Reformatsky reaction between diethyl bromomalonate and N-arylpyrrolidine-2-thiones 8, followed by cyclisation of the resulting enaminone intermediates 9 in polyphosphoric acid.

CHEMISTRY AND CYCLIZATION REACTIONS OF 2-MERCAPTO-3-PHENYL PYRIMIDO THIENO[2,3-b]QUINOXALINONE DERIVATIVES

Abstract Reaction of 2-mercapto-3-phenyl pyrimido[4′,5′:4,5]thieno[2,3,-b]quinoxalin-4-one(1) with hydra-zine hydrate gives 2-hydrazino derivative (2) which undergoes ring closure reactions with formic acid, acetic anhydride, and benzoyl chloride to produce the S-triazolo derivatives(3–5). While treatment with nitrous acid gives the tetrazolo derivative (6). Reaction of (2) with acetylacetone, phthalic anhydride, and/or aromatic aldehydes affords, N-pyrazolyl-N-phthalazino- and N-arylidene derivatives (7–9) respectively. Compound (1) reacts with alkyl halides in basic medium to give the corresponding thioethers (10). Compound (1) reacts with diethyl bromomalonate to yield (11) which is transformed into (12a.b) under the influence of hydrazine or phenylhydrazine. Treatment of (1) with ethyl chloroacetate yields the thioester (13). Reaction of (1) with chloroacetamide or (13) with ammonia gave the same product. Hydrazinolysis of the thioester (13) gave the corresponding carbohydrazide (15) which reacts with...

A synthesis of functionalized indoline 2,2-biscarboxylates

A synthetic approach to a structurally novel series of indoline 2,2-biscarboxylates is described that employs a tandem bis-alkylation strategy to cyclize the indoline heteroring from the bromide 7 and diethyl bromomalonate. The indolines thus prepared may be N-deprotected and further functionalized on the indoline nitrogen.

Differentiation of Isomers Resulting from Bisaddition to C60 Using 3He NMR Spectrometry

{sup 3}He NMR spectrometry has been used to examine bisaddition to C{sub 60} containing an encapsulated {sup 3}He atom ({sup 3}He@C{sub 60}) using three types of reactions: (1) cyclopropanation with diethyl bromomalonate and base to give dicarbethoxymethanofullerenes (Bingel-Hirsch reaction), (b) addition of azomethine ylides to give N-methyl-fulleropyrrolidines (Prato-Wudl reaction), and (c) reduction to give C{sub 60}H{sub 4}. {sup 3}He NMR spectra of crude reaction mixtures in all three series showed well-separated resonances for each of the bisadducts, spread out over more than 2 ppm. The major isomeric bisadducts from the first two reactions were separated and characterized, and the {sup 3}He NMR spectra of the individual major bisadducts from {sup 3}He@C{sub 60} were obtained (five isomers from reaction 1, four isomers from reaction 2). Although the absolute chemical shifts in the two series of bisadducts differ, the relative chemical shifts are significantly but not perfectly correlated. The very large differences in the {sup 3}He NMR chemical shifts of the isomeric bisadducts in all three reactions demonstrate that the magnetic field felt by the {sup 3}He atom due to the ring currents in the residual {pi}-system is extremely sensitive to the pattern of ligation on the C{sub 60} surface. These resultsmore » provide further support for the assertion that {sup 3}He NMR is very sensitive probe of patterns of chemical addition to fullerenes. 21 refs., 4 figs.« less

Novel dibenzo[d,f][1,3]dioxepines

Two novel syntheses of dibenzo[d,f][1,3]dioxepines starting with biphenol are described. Treatment of biphenol 11a with 2-chloroacrylonitrile gave a 47% yield of dibenzo[d,f][1,3]dioxepin-6-acetonitrile 4, and treatment of 11a with two equivalents of diethyl bromomalonate gave a 95% yield of diethyl dibenzo[d,f][1,3]dioxepin-6,6-dicarboxylate 5a.

Regiochemistry of Multiple Additions to the Fullerene Core: Synthesis of a Th-Symmetric Hexakis adduct of C60 with Bis(ethoxycarbonyl)methylene

In this work, we report for the first time a systematic and stepwise synthesis of a T[sub h]-symmetric hexakisadduct of C[sub 60] with an increasing regioselectivity. Furthermore, we present a theoretical explanation for the regioselectivity of nucleophilic additions on the basis of the calculated coefficients of low-lying unoccupied orbitals (LUMO, LUMO+1, LUMO+2) as well as the thermodynamic stability of the adducts. As model reaction, we chose the cyclopropanation of C[sub 60] with diethyl bromomalonate in the presence of sodium hydride at room temperature. 5 refs., 3 figs.

Synthesis and pharmacological activities of novel cyclic disulfide and cyclic sulfide derivatives as hepatoprotective agents.

In order to search for anti-hepatitis drugs, we synthesized a series of eight- and nine-membered cyclic disulfides (1) and six- and seven-membered cyclic sulfides (2) and evaluated them for ability to reduce mortality in the model of acute hepatic failure induced by Propionibacterium acnes-lipopolysaccharide in mice. Compounds 1 were synthesized by oxidative cyclization of the corresponding dithiol derivatives (3) with diethyl bromomalonate or iodine. Compounds 2 were prepared from the methyl esters of 1 by desulfurization with tris(diethylamino)phosphine followed by deprotection. Compounds 1 were generally found to be more active than compounds 2. Compound 1b (SA3443) was found to exhibit potent protective activity. The synthesis and structure-activity relationships are discussed.

ChemInform Abstract: Benzylic Hydrogen Atom Abstraction Utilizing Diethyl Bromomalonate as a Radical Source.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Benzylic hydrogen atom abstraction utilizing diethyl bromomalonate as a radical source

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTBenzylic hydrogen atom abstraction utilizing diethyl bromomalonate as a radical sourceScott V. Truksa, Alan Nibler, Bruce S. Schatz, Kevin W. Krosley, and Gerald Jay GleicherCite this: J. Org. Chem. 1992, 57, 10, 2967–2970Publication Date (Print):May 1, 1992Publication History Published online1 May 2002Published inissue 1 May 1992https://doi.org/10.1021/jo00036a044RIGHTS & PERMISSIONSArticle Views801Altmetric-Citations6LEARN 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 (524 KB) Get e-Alerts Get e-Alerts

ChemInform Abstract: Reinvestigation of a Reported Synthesis of a Series of Tetracarbonylmethanes.

AbstractThe aroyl chlorides (I) react with diethyl bromomalonate (II) in the presence of tributylarsine to produce the benzoyloxybenzylidenemalonates (III).

Polycondensed heterocycles. IV. synthesis of 1,4‐dioxo‐2,3,3a,4‐tetrahydro‐1H‐pyrrolo[2,1‐c][1,4]benzothiazine

AbstractA method for the synthesis of the title compound 3 consisted of an intramolecular cyclization in a stannic chloride catalyzed Friedel‐Crafts reaction of N‐(2‐methylthiophenyl)‐5‐oxoproline chloride 10, prepared by chlorination of the corresponding acid 9 obtained by hydrolysis of its ethyl ester 8. Condensation of 2‐methylthioaniline 4 with diethyl bromomalonate 5 afforded diethyl 2‐methylthioanilinomalonate 6 which gave 8 either directly by reaction with ethyl acrylate or by alkylation with ethyl β‐bromopropionate or ethyl acrylate and cyclization of resulting triethyl 2‐(2‐methylthio)anilino‐2‐carboxyglutarate 7. This method was not convenient because of the poor yield of 3 (14%).On the other hand, cyclization of N‐(2‐mercaptophenyl)‐5‐oxoproline 14 with DCC and DMAP provided 3 in 45% yield. Oxidation with m‐CPBA of the esters 11 and 8, demethylation via the Pummerer rearrangement of the respective sulphoxides 12 and 17 with TFAA and oxidation with iodine of resulting N‐(2‐mercap‐tophenyl)‐5‐oxoproline esters 13 and 18 gave the corresponding disulphides 16 and 19. Hydrolysis of these latter compounds and reduction of the resulting bis[2‐[2‐(hydroxycarbonyl)‐5‐oxo‐1‐pyrrolidinyl]phenyl] disulphide 15 with sodium dithionite afforded the required 14. Deprotection of t‐butyl ester 13 with TFA at 55° to obtain 14 led to 3 in 42% yield. Finally the Pummerer rearrangement of N‐(2‐methylsulphinylphenyl)‐5‐oxo‐proline 20 yielded the mixture of 14 and 15.

ChemInform Abstract: Studies in the Synthesis of Furochromenes as Pharmacochemical Analogues of Psoralen and Allopsoralen. Part 1.

AbstractCyclocondensation of the dihydrobenzopyrans (I) with diethyl bromomalonate (II) leads to the formation of the furochromancarboxylic acids (III) which are dehydrogenated with DCC to form the furochromenecarboxylic acids (IV).

�ber Reaktionen mit Betain, 24. Mitt.: �ber Umsetzungen von Trimethylammoniumessigs�urebetain mit reaktiven Halogenverbindungen

Diethyl bromomalonate and bromoacetonitrile, respectively, react with trimethylammonium acetic acid betaine in ethanol to give diethyl tartronate and glycolic acid nitrile, respectively. By analogy, ethyl α-chloroacetonate and ethyl bromopyruvate yield the respective hydroxy derivatives which were identified by their osazones2 and3. Under the same experimental conditions, mesoxalic acid and its dimethyl ester, respectively, are formed from dibromo malonic acid and its dimethyl ester and were characterized by their known hydrazones8 and9.

ChemInform Abstract: Conversion of Thiols into Disulfides with Diethyl Bromomalonate.

AbstractDie Thiole(I) lassen sich mit Brommalonester (II) oxidativ zu den Disulfiden (III) kuppeln.

Conversion of thiols into disulfides with diethyl bromomalonate.

Conversion des alcanethiols, arenethiols, cysteine, thiamine en les disulfures correspondants

Addition of diethyl bromomalonate and diethyl dibromomalonate to vinyltrimethylsilane

1. Diethyl dibromomalonate and diethyl bromomalonate add to vinyltrimethylsilane upon initiation by dibenzoyl peroxide to form the diethyl esters of (2-bromo-2-trimethylsilylethyl)-bromomalonic acid and (2-bromo-2-trimethylsilylethyl)malonic acid, respectively. The reactivity of diethyl dibromomalonate in this addition reaction is higher than for diethyl bromomalonate. 2. Metal carbonyl initiation in this reaction is not very efficient. In the case of diethyl bromomalonate, reduction of the addend becomes the major reaction in the case of such initiation.

Neue Heterocyclisierungen mit Malonestern 1,3-Dithiole; 1,3-Oxathiole; ?2-Oxazoline und das Vinylendipyridiniumdikation

The reaction of diethyl bromomalonate (1) or diethyl diazomalonate (6) with benzoyl isothiocyanate (2) proceeds via the carbene intermediates4, 7 or12 to afford the 1,3-dithiole5, the Δ2-oxazoline8 or the 1,3-oxathioles9 depending upon the catalyst employed. In contrast, the bis(ethoxycarbonyl)methylpyridinium bromides14 upon treatment with benzoyl isocyanates15 in pyridine give rise to vinylene dipyridinium dibromides18.

Phase-transfer catalyzed synthesis of activated cyclopropanes

The phase-transfer catalyzed condensation of diethyl bromomalonate (7d) with Michael acceptors 8–12 leads to cyclopropanes in high yields. More hindered acceptors and other haloesters do not react, while condensation of 7d with crotonaldehyde leads to a 2:1 adduct via a subsequent Darzens condensation. The synthetic potential of the products is also outlined.

Synthesis of 5‐methylfuro[3,2‐b]pyridine‐2‐carboxylic acid

AbstractOxidation of 3‐hydroxy‐6‐methyl‐2‐hydroxymethylpyridine with manganese dioxide yielded the corresponding aldehyde, the condensation of which with diethyl bromomalonate furnished hydroxydihydrofuro[3,2‐b]pyridinediearboxylie acid ester. Saponification of the diester with concentrated hydrochloric acid afforded the hydrochloride of 5‐methylfuro[3,2‐b]pyrjdine car‐boxylic acid.

Über Reaktionen mit Betain, ΧΠ. Das Verhalten von Brommalonsäure-diäthylester gegenüber tert. aliphat. Aminen / Reactions with Betaine, XII. The Reaction of Diethyl Bromomalonate with Aliphatic tert. Amines

Diethyl bromomalonate (1) reacts with trimethylamine at 0°C to give the bromide salt of trimethylammoniummalonate (2), however, in the presence of methanol, ethanol or 1-butanol the bromide of ethyl trimethylammoniumacetate (3) is obtained under the loss of dialkyl carbonates. The analogous reaction of 1 with dimethylsulfide yields diethyl methylthiomalonate (5).