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Showing papers on "Diazomethane published in 2013"


Journal ArticleDOI
TL;DR: A continuous process for generation, separation, and reactions of anhydrous diazomethane in a tube-in-tube reactor was developed, which allows safe and scalable reactions with dry diazometrichane to be performed on a laboratory scale.

145 citations


Journal ArticleDOI
Matthew Duncton1, Rajinder Singh1
TL;DR: Trans-2-(Trifluoromethyl)cyclopropylboronic acid N-methyliminodiacetic acid (MIDA) ester 5 was synthesized as a pure diastereomer from vinylboronic Acid MIDA ester and (trifluorbonic acid)diazomethane in a single step.

50 citations


Journal ArticleDOI
TL;DR: Several kinds of cycloaddition reactions were applied to C3-ethynylated pyropheophorbide-a methyl ester to develop C3 functionalized chlorophyll derivatives as discussed by the authors.

20 citations


Journal ArticleDOI
TL;DR: Membrane depolarization of Aplysia neurons upon application of the azakainoid demonstrates that it is an ionotropic glutamate receptor agonist.

10 citations


Journal ArticleDOI
TL;DR: In this paper, a convenient synthesis for 2-trifluorometylaziridine-2-carboxylates and respective acids, based on reaction of N-substituted trifluorsopyruvate imines 1 with diazomethane, was developed.

9 citations


Journal ArticleDOI
TL;DR: The tetramethoxy derivative of 5,11,17,23-tetranitrothiacalix[4]arene with diazomethane was studied using single-crystal X-ray crystallography.

6 citations


Journal ArticleDOI
TL;DR: In this article, three synthetic methods for the preparation of 3-pyrazole carboxylates featuring substituents on position 4 were investigated, based on the potassium permanganate oxidation of methyl pyrazoles.

6 citations



Journal ArticleDOI
TL;DR: A new class of pyrrolyl and pyrazolyl sulfonamides from styrene-ω-sulfonanilides by treatment with tosylmethyl isocyanide and diazomethane was proposed in this article.
Abstract: A new class of pyrrolyl and pyrazolyl sulfonamides was prepared from styrene-ω-sulfonanilides by treatment with tosylmethyl isocyanide and diazomethane, respectively.

3 citations


Journal ArticleDOI
TL;DR: In this article, the double-bonded ergot alkaloid derivatives containing a double bond in ring D have been reacted with diazomethane/palladium diacetate reagent to result in formation of a fused cyclopropane ring.
Abstract: Some ergot alkaloid derivatives containing a double bond in ring D have been reacted with diazomethane/palladium diacetate reagent to result in formation of a fused cyclopropane ring. This procedure proved to be generally applicable for cyclopropanation of Ergot alkaloids.

3 citations


Journal ArticleDOI
TL;DR: In this article, a 6-hydroxy-scaffold derivative of quinopimaric acid was synthesized in order to introduce a glycoside group into the scaffold derivative and to expand the range of functional derivatives of these compounds.
Abstract: Levopimaric acid occurs in sap of plants of the genus Pinus and has recently been used as a base for synthesizing biologically active compounds Diene adducts of levopimaric acid with quinones, which exhibit antitumor, anti-inflammatory, anti-ulcer, and antiviral activity, are highly interesting [1] Furthermore, diene adducts of levopimaric acid with quinones undergo readily intramolecular cyclization upon UV irradiation to form birdcage-type scaffold compounds [2, 3] Conjugation of biologically active compounds with carbohydrates is often used to increase the solubility of the target compounds [4] This can enhance the already existing bioactivity of the conjugates or cause the appearance of new types of activity [5] In this respect, it seemed interesting to glycosylate scaffold products from photochemical reactions of quinopimaric acid derivatives with an optically active diterpene and a unique scaffold in their structure in order to study the toxicity and structure–activity relationship and to expand the range of functional derivatives of these compounds We synthesized 6-hydroxy-scaffold derivative 1 in order to introduce a glycoside group into the quinopimaric acid scaffold derivative Diene synthesis of levopimaric acid and p-benzoquinone produced quinopimaric acid [2], regioselective reduction of which with NaBH4 in anhydrous MeOH gave 1-hydroxyquinopimaric acid [3] Subsequent photolysis of the ketoalcohol in EtOAc by an ORK-21sh quartz lamp produced 1 in 96% yield in the last step Methylation of 1 by diazomethane gave methyl ester 2 in 98% yield The stereochemistry of the C-6 hydroxy group in 1 was determined based on the stereochemistry of C-1 in 1-hydroxyquinopimaric acid, in which the OH group had the -orientation [6]

Journal ArticleDOI
TL;DR: In this article, a one-pot cycloaddition reaction followed by reductive ring cleavage (Zn/AcOH) is described, where the cycloadding reaction is followed by a reduction of the ring.
Abstract: Additionally a one-pot procedure for the cycloaddition reaction followed by reductive ring cleavage (Zn/AcOH) is described.

Patent
06 Feb 2013
TL;DR: In this article, a preparation method of L-N-Boc-high tryptophan methyl ester, which can be mainly used for solving the problems that the reaction steps are more, the cost is low, the operation is difficult, and the single chirality of a final compound can not be ensured in an existing synthesizing method.
Abstract: The invention discloses a preparation method of L-N-Boc-high tryptophan methyl ester, which can be mainly used for solving the problems that the reaction steps are more, the cost is low, the operation is difficult, and the single chirality of a final compound can not be ensured in an existing synthesizing method. The preparation method comprises the steps of conducting cyclization reaction to generate L-2-pyrrolidone-6-formic acid 1 by taking L-2-amino adipic acid as initial materials under the action of glacial acetic acid and water; 2. conducting an esterification reaction on the compound 1 and trimethyl silicon diazomethane to obtain L-2-pyrrolidone-6-methyl ester 2; 3. protecting N in the compound 2 by using Boc, then conducting the reduction reaction due to the action of a reducing agent, namely lithium triethylborohydride, and reducing carbonyl in the L-2-pyrrolidone-6-methyl ester protected by N-tert-butylcarbazate; and 4. finally synthesizing the high tryptophan methyl ester protected by the L-N-tert-butylcarbazate by two methods: synthesizing classical fisher benzazole in one method, and removing one molecular water by L-2-pyrrolidinol-6-methyl ester and iodoaniline, rearranging, and conducting Heck reaction under the action of a palladium catalyst to obtain the L-N-Boc-high tryptophan methyl ester in the other method.

Journal ArticleDOI
TL;DR: Ismailov et al. as discussed by the authors used diazomethane to transform cyclic amido acids I and II into endo-cis and exo-ceis amido esters III and IV by treatment with diazmethane in diethyl ether.
Abstract: Diazomethane is commonly used as efficient alkylating agent in the preparation of methyl esters and as a component in [2 + 3]-cycloaddition reactions [1]. However, there are no published data on dehydrating ability of diazomethane. With a view to accomplish cis–trans epimerization of cyclic amido acids I and II, an attempt was made to convert them into endo-cis and exo-cis amido esters III and IV by treatment with diazomethane in diethyl ether at 20°C. Unexpectedly, these reactions chemoselectively afforded the corresponding dicarboxylic acid imides V and VI, while even traces of esters III and IV were not detected. The structure of imides V and VI was confirmed by the H and C NMR spectra and independent synthesis from the corresponding anhydrides. It should be noted that known methods for the preparation of imides from amido acids require more severe conditions, in particular prolonged heating in high-boiling solvents (usually in DMF or Ac2O) in the presence of dehydrating agents [2]. rel-(1S,2R,3S,4R)-N-Benzyl-5,6,7,8-tetrachloro1,4-methano-1,2,3,4-tetrahydronaphthalen-2,3-dicarboximide (V). A solution of diazomethane in diethyl ether was added to a suspension of 0.9 g of amido acid I in diethyl ether until the mixture became homogeneous. The mixture was evaporated at 20oC, ISSN 1070-4280, Russian Journal of Organic Chemistry, 2013, Vol. 49, No. 10, pp. 1548–1549. © Pleiades Publishing, Ltd., 2013. Original Russian Text © S.A. Ismailov, 2013, published in Zhurnal Organicheskoi Khimii, 2013, Vol. 49, No. 10, pp. 1569–1570.

Journal ArticleDOI
TL;DR: Ozonolysis of ω-anhydro-20-hydroxyecdysone diacetonide gave a mixture of 24 and 25-oxo derivatives, and only the first of these (23-carbaldehyde) reacted with malonic acid according to Knoevenagel to give 14α,hydroxy-2β,3β: 20,22-bis(isopropylidenedioxy)-6-oxoxo-27-nor-5β-cholesta-7,24-dien-26-oic
Abstract: Ozonolysis of ω-anhydro-20-hydroxyecdysone diacetonide gave a mixture of 24- and 25-oxo derivatives, and only the first of these (23-carbaldehyde) reacted with malonic acid according to Knoevenagel to give 14α-hydroxy-2β,3β: 20,22-bis(isopropylidenedioxy)-6-oxo-27-nor-5β-cholesta-7,24-dien-26-oic acid. The oxidation of 23-carbaldehyde with ozone, followed by treatment with diazomethane, afforded 20-hydroxy-25,26,27-trinorecdysone-23-carboxylic acid methyl ester diacetonide.

Journal ArticleDOI
TL;DR: In this article, the reaction of the silver salt of (2-methyltetrazol-5-yl)dinitromethane with cyanogen bromide led to the formation of 2-(2-mtetrazal-5]-2,2-dinitroacetonitrile.
Abstract: The reaction of the silver salt of (2-methyltetrazol-5-yl)dinitromethane with cyanogen bromide led to the formation of 2-(2-methyltetrazol-5-yl)-2,2-dinitroacetonitrile. The nitrile group of the latter was capable of entering into 1,3-dipolar cycloaddition with diazomethane, giving a mixture of isomeric 2-methyl-5-[(N-methyl-1,2,3-triazol-4-yl)dinitromethyl]tetrazoles that were separated by column chromatography. Upon treatment with an alcohol solution of potassium hydroxide, denitration of the cycloaddition products occurred and was accompanied by salt formation, leading to the potassium salts of 2-methyl-5-[(N-methyl-1,2,3-triazol-4-yl)(aci-nitro)methyl]tetrazoles.

Patent
10 Oct 2013
TL;DR: In this paper, an anionic part of a salt is substituted with the anionic parts of the first acid obtained from the anion part of the acid photogenerator, to form a second acid having acid strength lower than that of a first acid.
Abstract: FIELD: chemistry.SUBSTANCE: photosensitive composition contains a cation-polymerisable compound, an acid photogenerator having an anionic part and a cationic part, as well as a salt having a cationic part having anyone of a quaternary ammonium structure or a quaternary phosphonium structure, and an anionic part. The anionic part of the salt is substituted with the anionic part of the first acid obtained from the anionic part of the acid photogenerator, to form a second acid having acid strength lower than that of the first acid. The cation-polymerisable compound is an epoxy resin. The acid photogenerator is at least a compound selected from a group comprising a sulphonic acid compound and other sulphonic acid derivatives, a diazomethane compound, a sulphonium salt, an iodonium salt, a sulphonimide compound, a disulphonic compound, a nitrobenzene compound, a benzoin tosylate compound, an iron arene complex, a halogen-containing triadine compound, an acetophene derivative, and a cyano group-containing sulfatoxim. The method of forming a pattern involves preparing a substrate on which the photosensitive composition is provided. A portion of the composition is then exposed to light to cure the exposed portion. The cured portion is then heated. The liquid ejection head has a part with an outlet channel for ejecting liquid. The part with the outlet channel is formed from cured material made from said composition.EFFECT: invention increases heat resistance of the photosensitive composition and increases accuracy of forming a pattern.13 cl, 4 dwg, 5 tbl, 9 ex

Journal ArticleDOI
TL;DR: In this paper, an analog of tetrazole, 5-(chlorodinitromethyl)-2-methyl-2H-tetrazole (II), was synthesized and examined with diazomethane (III) and diazoethane (IV).
Abstract: It is known that 5-dinitromethyl-2-methyl-2H-tetrazole (I) reacts with diazomethane to give isomeric methyl (2-methyltetrazol-5-yl)nitromethanenitronates and (1,3-dimethyl-1H-tetrazol-5-yl)dinitromethylide [1]. With a view to study how the nature of substituted 5-dinitromethyltetrazoles affects the direction of their reactions with diazo compounds, we have synthesized an analog of tetrazole (I), 5-(chlorodinitromethyl)-2methyl-2H-tetrazole (II), and examined its reactions with diazomethane (III) and diazoethane (IV). Tetrazole (II) was prepared in 70% yield by chlorination of azole I potassium salt (Scheme 1). tion of C–O bond, yielding nitronic acid esters as primary O-alkylation products. These esters react with excess diazoalkane, thus being converted in succession into substituted ethenes and then cyclic esters, dihydroisoxazole N-oxides VI and VIII (Scheme 2). The product ratio is likely to be determined by higher reactivity of the ambident anion in the O-alkylation process.

Journal ArticleDOI
TL;DR: Copper-mediated cyclopropanation of dihydroimidazolones (I) using diazomethane (II) and methyl diazoacetate (VI) provides access to diazabicyclohexanones (IIIa, (IIIb), (VII, and (XI) and the first diaza[4.3.1]propellane (IIIc) as discussed by the authors.
Abstract: Copper-mediated cyclopropanation of dihydroimidazolones (I) using diazomethane (II) and methyl diazoacetate (VI) provides access to diazabicyclohexanones (IIIa), (IIIb), (VII), and (XI) and the first diaza[4.3.1]propellane (IIIc).

Journal ArticleDOI
TL;DR: In this paper, a commercially available silylboron was applied to the synthesis of α-amino acid esters from α -amidosulfones via carbon dioxide incorporation and subsequent esterification with diazomethane.
Abstract: A commercially available silylboron is successfully applied to the synthesis of α-amino acid esters from α-amidosulfones via carbon dioxide incorporation and subsequent esterification with diazomethane.

Patent
31 Oct 2013
TL;DR: In this paper, a method for producing hydridosilane oligomers containing carbon was proposed, where an optionally boron- or phosphorus-doped hydrisilane is reacted with at least one carbon source selected from linear, branched, or cyclic carbosilanes, halogenated hydrocarbons, carbenes, alkyl azides, diazomethane, dimethyl sulfate, or alcohols.
Abstract: The invention relates to methods for producing hydridosilanes containing carbon, wherein an optionally boron- or phosphorus-doped hydridosilane is reacted with at least one carbon source selected from linear, branched, or cyclic carbosilanes, halogenated hydrocarbons, carbenes, alkyl azides, diazomethane, dimethyl sulfate, or alcohols in the absence of catalysts and reductants. The invention further relates to the hydridosilane oligomers containing carbon that can be obtained in accordance with the method, and to the use of said hydridosilane oligomers.

Journal ArticleDOI
TL;DR: A new class of pyrrolyl and pyrazolyl sulfonamides from styrene-ω-sulfonanilides by treatment with tosylmethyl isocyanide and diazomethane was proposed in this article.
Abstract: A new class of pyrrolyl and pyrazolyl sulfonamides was prepared from styrene-ω-sulfonanilides by treatment with tosylmethyl isocyanide and diazomethane, respectively.

Journal ArticleDOI
TL;DR: In this paper, the reaction of imines with diazomethane give triazole derivatives as the major products along with the desired aziridines along with triazoles.
Abstract: Reaction of imines with diazomethane give triazole derivatives as the major products along with the desired aziridines.

01 Jan 2013
TL;DR: This article showed that cyclic amido acid (I) and its diastereomer (III) can be converted into corresponding amido esters by treatment with diazomethane, which results in the unexpected selective formation of corresponding dicarboxylic acid amides.
Abstract: Attempts to convert cyclic amido acid (I) and its diastereomer (III) into corresponding amido esters by treatment with diazomethane result in the unexpected selective formation of corresponding dicarboxylic acid amides.

Patent
31 Oct 2013
TL;DR: In this paper, a process for preparing carbon-containing hydridosilane oligomers is described, in which an optionally boron- or phosphorus-doped hydrisilane is reacted without catalyst and reducing agent with at least one carbon source selected from linear, branched or cyclic carbosilanes.
Abstract: The present invention provides processes for preparing carbon-containing hydridosilanes, in which an optionally boron- or phosphorus-doped hydridosilane is reacted without catalyst and reducing agent with at least one carbon source selected from linear, branched or cyclic carbosilanes, halogenated hydrocarbons, carbenes, alkyl azides, diazomethane, dimethyl sulphate or alcohols, the carbon-containing hydridosilane oligomers obtainable by the process and the use thereof.