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Cas Database

186581-53-3

186581-53-3

Identification

  • Product Name:diazomethane

  • CAS Number: 186581-53-3

  • EINECS:

  • Molecular Weight:42.0403

  • Molecular Formula: CH2N2

  • HS Code:

  • Mol File:186581-53-3.mol

Synonyms:

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Safety information and MSDS view more

  • Signal Word:no data available

  • Hazard Statement:no data available

  • First-aid measures: General adviceConsult a physician. Show this safety data sheet to the doctor in attendance.If inhaled If breathed in, move person into fresh air. If not breathing, give artificial respiration. Consult a physician. In case of skin contact Wash off with soap and plenty of water. Consult a physician. In case of eye contact Rinse thoroughly with plenty of water for at least 15 minutes and consult a physician. If swallowed Never give anything by mouth to an unconscious person. Rinse mouth with water. Consult a physician.

  • Fire-fighting measures: Suitable extinguishing media Use water spray, alcohol-resistant foam, dry chemical or carbon dioxide. Wear self-contained breathing apparatus for firefighting if necessary.

  • Accidental release measures: Use personal protective equipment. Avoid dust formation. Avoid breathing vapours, mist or gas. Ensure adequate ventilation. Evacuate personnel to safe areas. Avoid breathing dust. For personal protection see section 8. Prevent further leakage or spillage if safe to do so. Do not let product enter drains. Discharge into the environment must be avoided. Pick up and arrange disposal. Sweep up and shovel. Keep in suitable, closed containers for disposal.

  • Handling and storage: Avoid contact with skin and eyes. Avoid formation of dust and aerosols. Avoid exposure - obtain special instructions before use.Provide appropriate exhaust ventilation at places where dust is formed. For precautions see section 2.2. Store in cool place. Keep container tightly closed in a dry and well-ventilated place.

  • Exposure controls/personal protection:Occupational Exposure limit valuesBiological limit values Handle in accordance with good industrial hygiene and safety practice. Wash hands before breaks and at the end of workday. Eye/face protection Safety glasses with side-shields conforming to EN166. Use equipment for eye protection tested and approved under appropriate government standards such as NIOSH (US) or EN 166(EU). Skin protection Wear impervious clothing. The type of protective equipment must be selected according to the concentration and amount of the dangerous substance at the specific workplace. Handle with gloves. Gloves must be inspected prior to use. Use proper glove removal technique(without touching glove's outer surface) to avoid skin contact with this product. Dispose of contaminated gloves after use in accordance with applicable laws and good laboratory practices. Wash and dry hands. The selected protective gloves have to satisfy the specifications of EU Directive 89/686/EEC and the standard EN 374 derived from it. Respiratory protection Wear dust mask when handling large quantities. Thermal hazards

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Relevant articles and documentsAll total 236 Articles be found

Synthesis of cyclopropanated [2.2.1] heterobicycloalkenes: An improved procedure

Carlson, Emily,Duret, Guillaume,Blanchard, Nicolas,Tam, William

, p. 55 - 62 (2016)

A safer and improved method to our previous report on palladium-catalyzed cyclopropanation of heterobicyclic alkenes has been developed. By using tetrahydrofuran as the solvent and a more dilute aqueous NaOH solution for the generation of diazomethane fro

Scalable On-Demand Production of Purified Diazomethane Suitable for Sensitive Catalytic Reactions

Sheeran, Jillian W.,Campbell, Kiersten,Breen, Christopher P.,Hummel, Gerald,Huang, Changfeng,Datta, Anamika,Boyer, Serge H.,Hecker, Scott J.,Bio, Matthew M.,Fang, Yuan-Qing,Ford, David D.,Russell, M. Grace

, p. 522 - 528 (2021)

We have developed a convenient development-scale reactor (0.44 mol/h) to prepare diazomethane from N-methyl-N-nitroso-p-toluenesulfonamide (MNTS) in ~80% yield. Diazomethane (CH2N2) made with this reactor is extracted into nitrogen gas from the liquid reaction mixture, effectively removing it from reagents and byproducts that may interfere in subsequent reactions. Vertically oriented tubular reactors were used to produce and consume diazomethane in situ. Key features of this reactor include high productivity and correspondingly low reactor volume (reactor volume/liquid flow rate = 6.5 min) and a commercially available gas/liquid separator equipped with a selectively permeating hydrophilic membrane. The design of the reactor keeps the inventory below 53 mg of CH2N2 during normal operation. The reactor was demonstrated by generating CH2N2 that was used in a connected continuous reactor. We evaluated esterification reactions and a continuous Pd-catalyzed cyclopropanation reaction with the reactor and achieved high conversion with 1.5 and 4.1 equiv of MNTS precursor, respectively.

BACKBONE REARRANGEMENTS OF METHYL (-)-KAUR-9(11)-EN-19-OATE AND ITS EPOXIDE: STRUCTURES OF TWO DITERPENES OF A NEW SKELETAL TYPE

Nakano, Tatsuhiko,Spinelli, A. C.,Martin, A.,Usubillaga, A.,McPhail, Andrew P.,Onan, Kay D.

, p. 3627 - 3630 (1982)

Cleavage of the epoxide (2) of methyl (-)-kaur-9(11)-en-19-oate (1b) with boron trifluoride-ether in benzene and in acetic anhydride yielded (3a) and (3b), respectively.On epoxidation with m-chloroperbenzoic acid in the presence of N-nitrosomethyl urea, (1b) suffered a backbone rearrangement to form (6).

How nucleophilic are diazo compounds?

Bug, Thorsten,Hartnagel, Manfred,Schlierf, Clemens,Mayr, Herbert

, p. 4068 - 4076 (2003)

The kinetics of the reactions of benzhydryl cations with eight diazo compounds 1a-g were investigated photometrically in dichloromethane. The nucleophilicity parameters N and slope parameters s of these diazo compounds were derived from the equation log k

A carbonyl ylide cycloaddition approach to platensimycin

Kim, Chan Hyuk,Jang, Ki Po,Choi, Soo Young,Chung, Young Keun,Lee, Eun

, p. 4009 - 4011 (2008)

(Chemical Presented) Short and to the point: A formal synthesis of platensimycin has been accomplished by employing a carbonyl ylide [3+2] cycloaddition reaction (see scheme). This short and facile enantioselective synthesis of the pivotal tetracyclic precursor requires 11 steps and proceeds in 20% overall yield from isopropyl cyanoacetate.

The synthesis of O-substituted 3-oximes of 6α -methyl-16α, 17α-cyclohexanopregn-4-ene-3,20-diones tritium-labeled in the 1,2-position

Shevchenko,Nagaev,Levina,Kulikova,Myasoedov,Kamernitzky

, p. 263 - 268 (2010)

1,2-Tritium-labeled 3-(O-carboxypropyl)- and 3-(O-carbomethoxypropyl)- oximes of 6α-methyl-16α,17α-cyclohexanopregn-4-ene-3,20-diones were obtained by the homogeneous catalytic hydrogenation of 1,2-dehydroprecursors with gaseous tritium and the subsequent separation of the resulting mixtures by HPLC. The specific radioactivities of 50-55 Ci/mmol were prepared using tris-(triphenylphosphine)-rhodium chloride.

Concise synthesis of alkaloid (-)-205B

Rao, Nagavaram Narsimha,Cha, Jin Kun

, p. 2243 - 2246 (2015)

Described herein is a short total synthesis of alkaloid (-)-205B (1) by means of an anti-selective SN2 alkylation of an attractively functionalized cyclopropanol and diastereoselective cyclization of the resulting aminoallene adduct for bicyclic ring formation. The synthesis features a general route to cis- or trans-2,6-disubstituted piperidines by lithium aluminum hydride reduction of the imine intermediate by an appropriate choice of solvent and cis- or trans-2,5-disubstituted pyrrolidines by an exceptional level of chirality transfer from a pendant allene. Particularly noteworthy are the brevity and convergence made possible by a segment-coupling strategy.

Preparation of a bicyclic analogue of qinghao (artemisinic) acid via a Lewis acid catalyzed ion Diels-Alder reaction involving a hydroxy diene and cyclic enone and facile conversion into (±)-6,9-desdimethylqinghaosu

Haynes,King,Vonwiller

, p. 4743 - 4748 (1994)

Treatment of 6-methylcyclohex-2-enone (8) and hexa-3,5-dien-1-ol (14) either in dichloromethane at -20 to 0°C with aluminum chloride (1 equiv) or in acetonitrile at -20°C with Cu(II) trifluoromethanesulfonate (1 equiv) rapidly provides in a highly stereoselective reaction the hemiacetal Diels-Alder adduct 15, which with a trans ring junction and anti methyl group is considered to arise via an ionic Gassman-type Diels-Alder reaction involving prior formation of a hemiacetal between the alcohol and enone followed by generation of an allylic cation from the hemiacetal mediated by the Lewis acid. The adduct 15 is then converted in straightforward fashion into the methyl ester of the desdimethyl analogue of qinghao (artemisinic) acid, which upon sequential photosensitized oxygenation and then Fe(phen)3(PF6)3/copper(II) triflate catalyzed cleavage-oxygenation provides (±)-6,9-desdimethylqinghaosu.

An enantiospecific synthesis of a komarovispirane

Srikrishna, Adusumilli,Beeraiah

, p. 2587 - 2597 (2007)

The enantiospecific total synthesis of a komarovispirane, containing the complete carbon framework, trans-bicyclo[4.3.0]nonanespiro[8.1′]cyclohexane, of the spiroditerpene komarovispirone, starting from the readily available campholenaldehyde is described

Design and Discovery of Functionally Selective Serotonin 2C (5-HT2C) Receptor Agonists

Cheng, Jianjun,McCorvy, John D.,Giguere, Patrick M.,Zhu, Hu,Kenakin, Terry,Roth, Bryan L.,Kozikowski, Alan P.

, p. 9866 - 9880 (2016)

On the basis of the structural similarity of our previous 5-HT2C agonists with the melatonin receptor agonist tasimelteon and the putative biological cross-talk between serotonergic and melatonergic systems, a series of new (2,3-dihydro)benzofu

Isolation and structural identification of a direct-acting mutagen derived from N-nitroso-N-methylpentylamine and Fenton's reagent with copper ion

Miura, Motofumi,Inami, Keiko,Yoshida, Masafumi,Yamaguchi, Kentaro,Mashino, Tadahiko,Mochizuki, Masataka

, p. 5693 - 5697 (2011)

N-Nitrosodialkylamines show their mutagenicity by forming α-hydroxynitrosamines in the presence of rat S9 mix in the Ames assay. The hydroxyl radical derived from Fe2+-H2O2 (Fenton's reagent) with Cu2+ activates N-nitrosamines, with an alkyl chain longer than a propyl constituent, to a direct-acting mutagen. The reactivity of Fe2+-Cu2+-H2O2 on nitrosamines in relation to their metabolic activation is not fully characterized. Here, we report the identification of the direct-acting mutagen derived from N-nitroso-N-methylpentylamine (NMPe) in the presence of Fe 2+, Cu2+, H2O2 and nitric oxide (NO), which is a product of nitrosamine metabolism. A dichloromethane extract of the NMPe reaction mixtures was fractionated by silica gel column chromatography several times and by a preparative high performance liquid chromatography (HPLC); we obtained white crystals as a product. The direct-acting mutagen that was isolated was provisionally identified as 5-ethyl-5-nitro-1-pyrazoline 1-oxide by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy, infrared (IR) spectroscopy and X-ray crystallography. To confirm the structure of the mutagen, the authentic compound was synthesized from 2-nitrobutene and diazomethane, followed by N-oxidation with m-chloroperoxybenzoic acid. The 1H NMR spectral data from the direct-acting mutagen that was synthesized was identical to the data from the isolated mutagen. Furthermore, the authentic 5-ethyl-5-nitro-1-pyrazoline 1-oxide was mutagenic in Salmonella typhimurium TA1535. The results showed that 5-ethyl-5-nitro-1-pyrazoline 1-oxide was a direct-acting mutagen derived from the reaction of NMPe and Fe2+-Cu2+-H2O 2-NO.

Secondary metabolites from anti-insect extracts of endophytic fungi isolated from Picea rubens

Sumarah, Mark W.,Puniani, Eva,S?rensen, Dan,Blackwell, Barbara A.,Miller, J. David

, p. 760 - 765 (2010)

The extracts of a selection of 150 foliar fungal endophytes isolated from Picea rubens (red spruce) needles were screened by LC-MS and assayed for toxicity. Three of these strains that were toxic to the forest pest Choristoneura fumiferana (eastern spruce budworm) in dietary bioassays were selected for further study. Their culture extracts were analyzed by LC-NMR spectroscopy, and the major metabolites were isolated by LC-MS-SPE or PTLC/column chromatography and characterized. The structures were elucidated by spectroscopic analyses including 2D NMR, HRMS and by comparison to literature data. Compounds 1 and 5-7 are hitherto unknown whereas compounds 2 and 3 are natural products described for the first time. Compound 4 is reported for the first time as a fungal metabolite and 8-9 were identified as known fungal metabolites in genera.

Carbenoid insertion into the peroxide bond vs the olefin bond of cyclic peroxides

Zvarec, Ondrej,Avery, Thomas D.,Taylor, Dennis K.

, p. 450 - 454 (2010)

(Chemical Equation Presented) Herein we report examples of the insertion of a carbenoid into a peroxide linkage. This study reveals that intramolecular insertion of carbenes into the peroxide linkage of 3,6-dihydro-1,2-dioxines is preferred over olefin insertion. The initial scope of the reaction and mechanistic considerations, have been probed. This methodology also generates unusual bicyclic hemiacetals (2) and tricyclic peroxides (3).

Mechanism of decomposition of (E)-methanediazoate in aqueous solutions

Hovinen, Jari,Finneman, Jari I.,Satapathy, Surya N.,Ho, Jian,Fishbein, James C.

, p. 10321 - 10328 (1992)

Rate constants for the decomposition of (E)-methanediazoate (1) at 25°C, ionic strength 1 M (NaClO4), are independent of the concentration of nucleophile in up to 0.25 M propylamine base, 0.5 M methoxyamine base, 0.20 M thiosulfate dianion, and 0.50 M azide ion. When the CH3 group of 1 is transferred to benzoate ions, benzyl alcohol, and water upon decomposition in near neutral D2O solutions, the isotopic integrity of the methyl group is maintained to the extent of 70-90%. The rate constant for the decomposition of protonated 1 in ethanol is 680 times slower than that in aqueous 4% ethanol under identical buffering and ionic strength conditions. Trapping of the methyl group derived from 1 by two pairs of nucleophiles gives the same ratios of methylated products as those determined from the decomposition of diazomethane. The solvent deuterium isotope effect for the decomposition of the protonated form of 1 is kH2o/kH2O = 1.49 ± 0.09, and the activation parameters for its decomposition are ΔH? = 69.6 ± 1.5 kJ/mol and ΔS? = -4.5 ± 9.5 J/deg mol. It is concluded that 1 decomposes via equilibrium protonation on oxygen with subsequent rate-limiting cleavage of the O-N bond of the diazoic acid to yield the methanediazonium ion. This conclusion and measurements of the rate constants for decomposition of diazomethane under comparable conditions (25°C, aqueous 5% acetonitrile, ionic strength 0.20 M) permit the first semiquantitative description of the decomposition of a simple alkanediazoate and associated intermediates in wholly or predominately aqueous media.

Vibrational Energy Distributions of Singlet Methylene from Photolyses Ketene, Ketene-d2, Diazomethane, and Diazomethane-d2 at Several Wavelengths. A Chemically Activated Methylcyclobutene Study

Mahone, W. C.,Kolln, W.,Simons, J. W.

, p. 3902 - 3907 (1985)

The energy distributions of singlet methylene upon reaction with cyclobutane have been determined for methylene from photolysis of ketene and ketene-d2 at 214 nm, diazomethane at 436, 366, 337, 229 nm, and diazomethane-d2 at 366 nm.Earlier results for diazomethane photolyses at 436 and 366 nm are extended and reanalyzed in terms of a more recent stepsize determination for collosional deactivation of chemically activated methylcyclobutane.The widths of the singlet methylene energy distributions were found to increase with increasing photon energy and with deuterium substitution.An extensive analysis in terms of a statistical energy partitioning model for photodissociation of ketene and diazomethane is given and discussed.

X-ray crystal structure of grandiflorenic acid [(-)-kaura-9(11)-16-dien-19- oic acid] methyl ester, a compound formerly considered as an oily derivative

Cruz-Mondragon, Perla,Concepcion Lozada,Ortiz, Benjamin,Enriquez, Raul G.,Soriano-Garcia, Manuel

, p. 474 - 477 (2009)

Grandiflorenic acid [(-)-kaura-9(11)-16-dien-19-oic acid] methyl ester (2), C21H30O2, was synthesized from grandiflorenic acid, isolated from the plant Montanoa tomentosa. Compound (2) was formerly described as an oily derivative. X-ray diffraction analysis of (2) demonstrated that it consists of four rings, three six-membered rings (I, II and III) and one five-membered ring (IV). I, II and III rings occur in chair, twist, and envelope conformations, respectively. Ring IV occurs in a conformation between envelope and half-chair. The crystal of grandiflorenic acid methyl ester is in monoclinic crystal system with space group P21, lattice constants: a = 7.2170(10), b = 11.4170(10), c = 11.2850(10) A, β = 98.700(10)°, V = 919.1(2) A3 and Z = 2.

Antiparasitic activity of natural and semi-synthetic tirucallane triterpenoids from Schinus terebinthifolius (anacardiaceae): Structure/activity relationships

Morais, Thiago R.,Da Costa-Silva, Thais A.,Tempone, Andre G.,Borborema, Samanta Etel T.,Scotti, Marcus T.,De Sousa, Raquel Maria F.,Araujo, Ana Carolina C.,De Oliveira, Alberto,De Morais, Sergio Antonio L.,Sartorelli, Patricia,Lago, Joao Henrique G.

, p. 5761 - 5776 (2014)

Leishmaniasis and Chagas are diseases caused by parasitic protozoans that affect the poorest population in the World, causing a high mortality and morbidity. As a result of highly toxic and long-term treatments, the discovery of novel, safe and more efficacious drugs is essential. In this work, the in vitro antiparasitic activity and mammalian cytotoxicity of three natural tirucallane triterpenoids, isolated from leaves of Schinus terebinthifolius (Anacardiaceae), and nine semi-synthetic derivatives were investigated against Leishmania (L.) infantum and Trypanosoma cruzi. Trypomastigotes of T. cruzi were the most susceptible parasites and seven compounds demonstrated a trypanocidal activity with IC50 values in the range between 15 and 58 μg/mL. Four compounds demonstrated selectivity towards the intracellular amastigotes of Leishmania, with IC50 values in the range between 28 and 97 μg/mL. The complete characterization of triterpenoids was afforded after thorough analysis of nuclear magnetic resonance (NMR) data as well as electrospray ionization mass spectrometry (ESI-MS). Additionally, structure-activity relationships were performed using Decision Trees.

Enantiospecific synthesis of angular triquinanes

Srikrishna, Adusumilli,Gowri, Vijayendran

, p. 1553 - 1559 (2011)

The enantiospecific synthesis of angular triquinanes has been developed starting from the readily available (S)-campholenaldehyde. Two alternate strategies have been used, one employing a Johnson's orthoester Claisen rearrangement followed by an intramolecular cyclopropanation and regioselective cyclopropane ring cleavage, and a second one based on a RCM reaction.

Synthesis of carbazole analogs via Grob fragmentation of norbornyl α-diketones

Sravanthi, Kadavergu,Agrawal, Sumit Kumar,Rao, Chintada Nageswara,Khan, Faiz Ahmed

, p. 3449 - 3452 (2016)

A regioselective synthesis of carbazole analogs belonging to both the categories of natural origin, viz., microorganisms and higher plant source is reported. The synthesis of carbazole derivatives possessing a methylester group at C-1 position has been ac

Pyrenes and pyrendiones from Uvaria lucida

Moriyasu, Masataka,Takeuchi, Sousuke,Ichimaru, Momoyo,Nakatani, Noriyshi,Nishiyama, Yumi,Kato, Atsushi,Mathenge, Simon G.,Juma, Francis D.,ChaloMutiso, Patrick B.

, p. 453 - 458 (2012)

A chemical investigation of the chloroform extract of the roots of Uvaria ludida Benth. (Annonaceae), an important African traditional medicine, led to the isolation of six new compounds; three pyrenes, 2-hydroxy-1,8- dimethoxypyrene (1), 8-methoxy-1,2-methylenedioxypyrene (2), and 7-hydroxy-8-methoxy-1,2-methylenedioxypyrene (3), two pyrenediones, 2-hydroxy-1,8-pyrenedione (4) and 2-methoxy-1,8-pyrenedione (5), and a sesquiterpene, (-)-10-oxo-isodauc-3-en-15-oic acid (6), together with eight known compounds (7-14). The structural elucidation by spectroscopic studies of the compounds isolated is described. While pyrenes did not exhibit strong cytotoxicity against human promyelocytic leukemia HL-60 cells, pyrenediones showed strong cytotoxicity. The IC50 of 4 was 70 ng mL-1, which was close to that of etoposide (IC50 = 60 ng mL-1). The Japanese Society of Pharmacognosy and Springer 2011.

Design and synthesis of novel xyloketal derivatives and their vasorelaxing activities in rat thoracic aorta and angiogenic activities in zebrafish angiogenesis screen

Xu, Zhongliang,Li, Yiying,Xiang, Qi,Pei, Zhong,Liu, Xilin,Lu, Bingtai,Chen, Ling,Wang, Guanlei,Pang, Jiyan,Lin, Yongcheng

, p. 4642 - 4653 (2010)

A novel series of xyloketal derivatives (1-21) were designed and prepared. The majority of the compounds demonstrated vasorelaxation action on 60 mM KCl-induced contractions rat isolated aortic rings in a concentration-dependent manner, and the action is mediated by both endothelium-independent and endothelium-dependent mechanisms. Compounds 9, 12, 13, 14, 15, and 19 showed higher vasorelaxation activities comparing with the lead compound 3. In addition, these derivatives had potential protective action against oxLDL-induced endothelial oxidative injury and enhanced NO production in HUVECs without toxic effects. The NO release was completely inhibited by eNOS inhibitor L-NAME. Furthermore, 3 significantly promoted the angiogenesis in zebrafish in a concentration-dependent manner at 0.1, 1, and 10 μM. Compounds 9, 12, 14, 16, 20, and 21 exhibited stronger angiogenic activities than 3. Therefore, xyloketal derivatives are unique compounds with multiple pharmacological properties and may have potential implications in the treatment of cardiovascular diseases.

Unsymmetrically, Chemically Activated 1,2-Dicyclopropylacetylene: An Example of Restricted Energy Flow?

Doering, W. von E.,Ehlhardt, William J.

, p. 2697 - 2706 (1987)

The Doering-Gilbert-Leermakers strategy for revealing chemical reaction possibly more rapid than internal flow of energy is applied to 1,2-dicyclopropylacetylene by examining addition of dideuteriomethylene to 1-cyclopropyl-2-vinylacetylene and of methylene to 1-(2,2-dideuteriocyclopropyl)-2-vinylacetylene in the gas phase.This reduction to practice of the general strategy has three advantages: one of the three isomers of allylcyclopropylacetylene, itself the key product of chemically activated rearrangement, bears internal witness to the achievement of structural symmetry prior to its generation; the long, linear acetylenic linkage precludes internal energy flow by a mechanism of intramolecular collision; and the activation energy of the cyclopropane-propene rearrangement is lowered significantly.Analysis of the experimental results reveals a small amount of rearrangement at high pressures occurring prior to complete symmetrization of structure and/or energy.If this observation can be ascribed to incomplete symmetrization of energy, the basic premise of the Rice-Ramsperger-Kassel-Marcus theory-that internal energy flow be so much faster than chemical reaction that a structureless statistical treatment is justified-may require reconsideration.

Syntheses of spiroindole melatonin analogues via 2-(indolin-3-ylidene)acetonitrile cycloadditions

Lozinskaya, Natalia A.,Volkova, Maria S.,Seliverstov, Michael Yu.,Temnov, Victor V.,Sosonyuk, Sergey E.,Proskurnina, Marina V.,Zefirov, Nikolai S.

, p. 260 - 261 (2014)

2-(2-Oxo-1,2-dihydro-3H-indol-3-ylidene)acetonitriles were subjected to cycloaddition reactions at the double bond affording spiroindole melatonin analogues.

Synthesis of Cyclopropanated 7-Azabenzonorbornadienes

Carlson, Emily,Tam, William

, p. 2449 - 2454 (2016)

7-Azabenzonorbornadienes bearing various aryl or N-substituents were treated with diazomethane in the presence of palladium to afford desirable yields of cyclopropanated products (75-98%). The current approach suggests an efficient synthesis for CH2-cyclopropanated 7-azabenzonorbornadienes which lends promise to the development of new ring-opening preparations of biologically useful organic frameworks.

Stereospecific mono- and difluorination of the C7-bridge of norbornenes

Rajsfus, David E.,Alter-Zilberfarb, Sari,Sharon, Pessia,Meador, Mary Ann B.,Frimer, Aryeh A.

, p. 339 - 347 (2011)

Fluorinated norbornenes are very desirable monomers in the semiconductor and high-temperature polyimide industries. We describe herein a synthetic strategy for the stereospecific mono- or difluorination of the C 7-carbon in norbornene systems beginning with 7-ketonadic anhydride 1. In particular, anti-7-fluoro methyl diester 4 and its 7,7-difluoronadic analog 7 can be prepared from 1 in 3 or 4 steps: saponification, reduction (for 4), esterification, fluorination with DAST. In addition, anti-7-fluoro-syn-7- fluoromethylnadic diester 16 is obtained from epoxide 14, and dimethyl 7,7-difluorobicyclo[2.2.2]oct-5-ene-2,3-dicarboxylate (17) from ketone 15. Anchimeric assistance of the norbornene double bond guides the introduction of attacking fluoride anions stereospecifically anti to the olefinic linkage.

The Rates of Diazomethane Formation from Methylnitrosoamides. The Stability of Diazomethane Solutions towards Aqueous Alkalis

Pearce, Michael

, p. 887 - 891 (1980)

The rate of hydrolysis of N-methyl-N-nitrosoamides by aqueous alkalis varies greatly.Methylnitrosourea (1) is hydrolyzed rapidly by aqueous KOH-solutions at low temperatures to give a high yield of diazomethane.Under similar conditions, N,N'-dimethyl-dinitroso-oxamide (3) is hydrolyzed more slowly, but also gives a good yield of diazomethane.N,N'-Dimethyl-N,N'-dinitrosoterephthalamide (4), and (N-methyl-N-nitroso)-4-amino-4-methyl-2-pentanone (5) are less easily hydrolyzed by aqueous KOH-solutions.N-Methyl-N-nitroso-p-toluenesulfonamide (2) was the least reactive out of those tested.The hydrolysis of diazomethane in toluene with aqueous bases follows first order kinetics.The hydrolysis rate is greatly influenced by the concentration and strength of the base and temperature.

Perfluoro-tert-butyl-homoserine as a sensitive 19F NMR reporter for peptide-membrane interactions in solution

Buer, Benjamin C.,Levin, Benjamin J.,Marsh, E. Neil G.

, p. 308 - 314 (2013)

Fluorine (19F) NMR is a valuable tool for studying dynamic biological processes. However, increasing the sensitivity of fluorinated reporter molecules is a key to reducing acquisition times and accessing transient biological interactions. Here,

Stereoselective synthesis of γ-lactone fused cyclopentanoids

Guemues, Ayseguel,Tanyeli, Cihangir

, p. 1405 - 1409,5 (2012)

The stereoselective synthesis of γ-lactone fused cyclopentanoids applying chemoenzymatic methods is described. rac-2-Hydroxymethyl-1,4,5,6- tetrachloro-7,7-dimethoxybicyclo[2.2.1]hept-5-ene and rac-2-hydroxymethyl-1,4,5, 6,7,7-hexachlorobicyclo[2.2.1]hept-5-ene were successfully resolved by Candida rugosa lipase (CRL), to afford enantiomerically enriched products with an ee of 94 and 97%, respectively. The enantiomerically enriched acetates were then subjected to ruthenium and/or cerium catalyzed oxidation to afford α-diketones and subsequent alkaline H2O2 mediated oxidative cleavage reaction of α-diketones, followed by CH 2N2 esterification, gave enantiomerically enriched γ-lactone fused cyclopentanoids with known absolute configurations.

Synthesis of halo-substituted framework derivatives of quinopimaric acid

Vafina,Uzbekov,Galin,Yunusov

, p. 1035 - 1038 (2014)

6-Chloro-, 6-chloroacetoxy-, and 16-(2-bromoacetyl)framework derivatives were synthesized from a photoadduct of quinopimaric acid.

An efficient process for synthesis of 2′-O-methyl and 3′-O-methyl guanosine from 2-aminoadenosine using diazomethane and the catalyst stannous chloride

Kore, Anilkumar,Parmar, Gaurang,Reddy, Srinu

, p. 307 - 314 (2006)

An improved strategy for the selective synthesis of 2′- O -methyl and 3′- O -methyl guanosine from 2-aminoadenosine is reported by using the catalyst stannous chloride. The regioselectivity of the 2′ and 3′- O -alkylation was achieved by optimizing the addition, timing, and concentration of the catalysts and diazomethane during the methylation reaction. An efficient and selective alkylation at 2′-OH of 2-aminoadenosine was achieved by mixing a stoichiometric amount of stannous chloride at room temperature in DMF. The reaction mixture was stirred at 50°C for 1 min and immediately followed by addition of diazomethane. The resulting 2′- O -methyl 2-aminoadenosine was treated with the enzyme adenosine deaminase, which resulted in an efficient conversion to the desired 2′- O -methylguanosine (98% yield). The product was isolated by crystallization. In contrast, the methylation at 3′-OH of 2-aminoadenosine was achieved by mixing a stoichiometric amount of stannous chloride in DMF and stirring at 50°C for 15 min, followed by addition of diazomethane. The resulting mixture containing 3′- O -methyl-2- aminoadenosine in 90% yield and 2′- O -methyl-2-aminoadenosine in 10% yield was treated with the enzyme adenosine deaminase, which preferentially deaminated only 3′- O -methyl-2-aminoadenosine, resulting in the production of 3′- O -methylguanosine in 88% yield. Due to the extremely low solubility 3′- O -methylguanosine, the compound precipitated and was isolated by centrifugation. This synthetic route obviates the chromatographic purification. Selective monomethylation is achieved by using the unprotected ribonucleoside. As a result, the method described herein represents a significant improvement over the current synthetic approach by providing superior product yield and economy, a much more facile purification of 2′,3′- O -methylated isomers, and eliminating the need for protected ribonucleosides reagents. Copyright Taylor & Francis Group, LLC.

Synthetic studies on strictamine: Unexpected oxidation of tertiary amine in Ru-catalyzed ring-closing olefin metathesis

Komatsu, Yoshiyuki,Yoshida, Kei,Ueda, Hirofumi,Tokuyama, Hidetoshi

, p. 377 - 380 (2013)

During synthetic studies toward strictamine, unexpected oxidation of tertiary amine to enamine was observed in ring-closing olefin metathesis (RCM) using Hoveyda-Grubbs 2nd catalyst. Control experiments under deoxygenated conditions indicated Ru-catalyst

SYNTHESIS AND NEUROPHARMACOLOGICAL ACTIVITY OF DISULFIDE DERIVATIVES OF PYRIDOXINE

Kovler, M. A.,Karaev, A. L.,Balyakina, M. V.,Zhukova, Z. N.,Avakumov, V. M.,Gunar, V. I.

, p. 747 - 749 (1988)

-

PROTONATION OF DIAZOMETHANE IN SUPERACID MEDIA.

McGarrity,Cox,Phillip

, p. 3961 - 3966 (1983)

Protonation on both terminals of diazomethane can be observed only under conditions of kinetic control in extremely acidic solutions, when the acidity is reduced only the thermodynamically more stable C-protonated isomer can be seen. Loss of nitrogen from the methanediazonium ion is nucleophile assisted in the very highly acidic medium of HOSO//2F/SbF//5/SO//2ClF.

AUTOMATED DIAZOMETHANE GENERATOR, REACTOR AND SOLID PHASE QUENCHER

-

Page/Page column 9-10; 14, (2022/03/09)

An automated apparatus (Diazo-M-pen and Diazo-M-cube) for production, utilization and quenching of highly toxic diazomethane comprising of integrated pumps, tubular flow reactor, liquid-liquid micro-separator, solid MOF quencher etc.

A simple method of synthesis of 3-carboxy-2,2,5,5-tetraethylpyrrolidine-1-oxyl and preparation of reduction-resistant spin labels and probes of pyrrolidine series

Dobrynin, Sergey A.,Usatov, Mikhail S.,Zhurko, Irina F.,Morozov, Denis A.,Polienko, Yuliya F.,Glazachev, Yurii I.,Parkhomenko, Dmitriy A.,Tyumentsev, Mikhail A.,Gatilov, Yuri V.,Chernyak, Elena I.,Bagryanskaya, Elena G.,Kirilyuk, Igor A.

, (2021/09/28)

Stable free radicals are widely used as molecular probes and labels in various biophysical and biomedical research applications of magnetic resonance spectroscopy and imaging. Among these radicals, sterically shielded nitroxides of pyrrolidine series demonstrate the highest stability in biological systems. Here, we suggest new convenient procedure for preparation of 3-carboxy-2,2,5,5-tetraethylpyrrolidine-1-oxyl, a reduction-resistant analog of widely used carboxy-Proxyl, from cheap commercially available reagents with the yield exceeding the most optimistic literature data. Several new spin labels and probes of 2,2,5,5-tetraethylpyrrolidine-1-oxyl series were prepared and reduction of these radicals in ascorbate solutions, mice blood and tissue homogenates was studied.

Biological evaluation of 3-benzylidenechromanones and their spiropyrazolines-based analogues

Adamus-Grabicka, Angelika A.,Budzisz, Elzbieta,Cieslak, Marcin,Hikisz, Pawe?,Królewska-Golinska, Karolina,Kusz, Joachim,Ma?ecka, Magdalena,Markowicz-Piasecka, Magdalena

, (2020/04/10)

A series of 3-benzylidenechrmanones 1, 3, 5, 7, 9 and their spiropyrazoline analogues 2, 4, 6, 8, 10 were synthesized. X-ray analysis confirms that compounds 2 and 8 crystallize in a monoclinic system in P21/n space groups with one and three molecules in each asymmetric unit. The crystal lattice of the analyzed compounds is enhanced by hydrogen bonds. The primary aim of the study was to evaluate the anti-proliferative potential of 3-benzylidenechromanones and their spiropyrazoline analogues towards four cancer cell lines. Our results indicate that parent compounds 1 and 9 with a phenyl ring at C2 have lower cytotoxic activity against cancer cell lines than their spiropyrazolines analogues. Analysis of IC50 values showed that the compounds 3 and 7 exhibited higher cytotoxic activity against cancer cells, being more active than the reference compound (4-chromanone or quercetin). The results of this study indicate that the incorporation of a pyrazoline ring into the 3-arylideneflavanone results in an improvement of the compounds’ activity and therefore it may be of use in the search of new anticancer agents. Further analysis allowed us to demonstrate the compounds to have a strong inhibitory effect on the cell cycle. For instance, compounds 2, 10 induced 60% of HL-60 cells to be arrested in G2/M phase. Using a DNA-cleavage protection assay we also demonstrated that tested compounds interact with DNA. All compounds at the concentrations corresponding to cytotoxic properties are not toxic towards red blood cells, and do not contribute to hemolysis of RBCs.

The reagent Et2AlX/CH2N2 in cyclopropanation of sterically hindered olefins, as well as oxygen- and nitrogen-containing unsaturated compounds

Ramazanov,Yaroslavova,Yaubasarov,Gil’manova,Dzhemilev

, p. 1869 - 1873 (2019/10/22)

A transition-metal-free method of cyclopropanation of sterically hindered olefins, substituted allylic alcohols, allylamines, and vinyl silyl ethers was developed using diazomethane in the presence of organic aluminum halides.

Process route upstream and downstream products

Process route

Conditions
Conditions Yield
With alkali;
N-methyl-N-nitroso-4-nitroaniline
943-41-9

N-methyl-N-nitroso-4-nitroaniline

Conditions
Conditions Yield
3-ethyl-2-methyl-1-nitro-2-pentanol

3-ethyl-2-methyl-1-nitro-2-pentanol

(S)-3-ethyl-2-methyl-1-nitro-2-pentanol

(S)-3-ethyl-2-methyl-1-nitro-2-pentanol

(R)-3-ethyl-2-methyl-1-nitro-2-pentanol

(R)-3-ethyl-2-methyl-1-nitro-2-pentanol

3-ethyl-2-pentanone
6137-03-7

3-ethyl-2-pentanone

Conditions
Conditions Yield
(R)-1,1'-bi-2-naphthol/La,Li heterobimetallic; (R)-6,6'-dimethoxybiphenyl-2,2'-diol/La,Li; In tetrahydrofuran; at -20 ℃; for 24h;
<13CO>-N-methyl-N-nitrosourea (MNU)

<13CO>-N-methyl-N-nitrosourea (MNU)

13C urea
58069-82-2

13C urea

carbonic acid monomethyl ester
7456-87-3

carbonic acid monomethyl ester

[<sup>13</sup><i>C</i>]cyanic acid
118832-13-6

[13C]cyanic acid

carbonate ion

carbonate ion

<sup>(13)</sup>CH<sub>2</sub>NO<sub>5</sub>P<sup>(2-)</sup>

(13)CH2NO5P(2-)

Conditions
Conditions Yield
With sodium hydroxide; phosphate buffer; In methanol; water; at 22 ℃; Product distribution; other reagents, temperature;
Conditions
Conditions Yield
In gaseous matrix; at -261.2 ℃; for 0.166667h; Product distribution; Mechanism; Irradiation; also by flash-vacuum pyrolysis (800 deg C);
2-ethyl-4-methyl-1-nitro-2-pentanol

2-ethyl-4-methyl-1-nitro-2-pentanol

(S)-2-ethyl-4-methyl-1-nitro-2-pentanol

(S)-2-ethyl-4-methyl-1-nitro-2-pentanol

(R)-2-ethyl-4-methyl-1-nitro-2-pentanol

(R)-2-ethyl-4-methyl-1-nitro-2-pentanol

5-methyl-3-hexanone
623-56-3

5-methyl-3-hexanone

Conditions
Conditions Yield
(R)-1,1'-bi-2-naphthol/La,Li heterobimetallic; (R)-6,6'-dimethoxybiphenyl-2,2'-diol/La,Li; In tetrahydrofuran; at -20 ℃; for 13h;
chloroform
67-66-3,8013-54-5

chloroform

methylhydrazine
60-34-4

methylhydrazine

Conditions
Conditions Yield
With potassium hydroxide; ethanol; hydrazine;
With potassium hydroxide; hydrazine;
diethyl ether
60-29-7,927820-24-4

diethyl ether

N,N'-dimethyl-N,N'-dinitroso-oxamide
7601-87-8

N,N'-dimethyl-N,N'-dinitroso-oxamide

ammonia
7664-41-7

ammonia

Oxalamide
471-46-5

Oxalamide

Conditions
Conditions Yield
analog verlaeuft die Einw. von Anilin, Hydrazinhydrat und Phenylhydrazin;
N-methyl-N-nitrosotoluene-p-sulfonamide
80-11-5

N-methyl-N-nitrosotoluene-p-sulfonamide

sodium tosylate
657-84-1

sodium tosylate

Conditions
Conditions Yield
With sodium hydroxide; cetyltrimethylammonim bromide; In ethanol; at 25 ℃;
With sodium hydroxide; sodium dodecyl-sulfate; In ethanol; at 25 ℃; Kinetics; other micellar aggregates; other solvent;

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