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Topic: Diazomethane

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	Paper
		Diazomethane can serve as a parent for CH3- because its most important resonance structure is only one step away from dissociation into CH2- and N2+.
		Since diazomethane is not the friendly type of gas that one would want to have sitting around the lab, we only generate enough to perform one day’s worth of spectroscopy at a time.
		Diazomethane has been studied and used in the world of organic chemistry for quite some time because of its effectiveness as a methylating reagent for carboxylic acids.
	www.physics.unlv.edu /~dbsommer/paper.html (1960 words)

	Diazomethane - Wikipedia, the free encyclopedia
		Diazomethane is prepared in the laboratory at mmol scale from diazomethane precursors such as Diazald or N-methyl-N-nitroso-p-toluenesulfonamide and MNNG or 1-methyl-3-nitro-1-nitrosoguanidine.
		Diazald in a solution of diglyme and diethyl ether reacts with a solution of potassium hydroxide in water at elevated temperatures and generated diazomethane is collected by distillation.
		Diazomethane is liberated from a solution of MNNG in diethyl ether by addition of sodium hydroxide in water at low temperatures.
	en.wikipedia.org /wiki/Diazomethane (204 words)

	Pyrazoles - LoveToKnow 1911
		It may also be prepared by the union of diazomethane with acetylene (H. v.
		They may be obtained by the reduction of pyrazoles (especially N-phenyl derivatives) with sodium in alcoholic solution; by condensing diazo-acetic ester or diazomethane with ethylenic compounds (fumaric ester, andc.) (E. Buchner, Ber., 1890, 23, p.
		Pyrazoline is' a colourless liquid which boils at 144° C. It may be prepared by the action of diazomethane on ethylene (E. arello, Gazz., 1906, 36, (i.), p.
	www.1911encyclopedia.org /Pyrazoles (944 words)

	Preparation of ester derivatives of fatty acids for chromatographic analysis
		There have been reports of etherification of hydroxy fatty acids with diazomethane, either with the absence of a small amount of methanol from the medium or in the presence of acidic or basic catalysts when reaction was prolonged [110,137], but this does not appear to be a problem otherwise.
		Diazomethane is potentially explosive and great care must be exercised in its preparation; in particular, apparatus with ground-glass joints and strong light must be avoided.
		Diazomethane [301] (see Section D.1) was one of the first methods to be used for selective methylation of free fatty acids, and it has been employed in analyses of this lipid fraction from plasma, when it has been reported to give reliable results [195,209,263,274].
	www.lipidlibrary.co.uk /topics/ester_93/index.htm (12584 words)

	Diazomethane - Free net encyclopedia
		Diazomethane is prepared in the laboratory at mmol scale from diazomethane precursors such as Diazald or N-methyl-N-nitroso-p-toluenesulfonamide and MNNG or 1-methyl-3-nitro-1-nitrosoguanidine.
		Diazomethane is liberated from a solution of MNNG in diethyl ether by addition of sodium hydroxide in water at low temperatures.
		Diazomethane may explode when in contact with ground-glass joints or when heated to about 100В°C, and a blast shield should be employed for its use.
	www.netipedia.com /index.php/Diazomethane (222 words)

	Diazomethane
		Effects on Animals: Diazomethane is a severe pulmonary irritant and a carcinogen and teratogen in laboratory animals; it is also mutagenic in bacteria [Parmeggiani 1983; Clayton and Clayton 1981].
		Before a worker is placed in a job with a potential for exposure to diazomethane, a licensed health care professional should evaluate and document the worker's baseline health status with thorough medical, environmental, and occupational histories, a physical examination, and physiologic and laboratory tests appropriate for the anticipated occupational risks.
		Diazomethane is not subject to EPA emergency planning requirements under the Superfund Amendments and Reauthorization Act (SARA) (Title III) in 42 USC 11022.
	www.osha.gov /SLTC/healthguidelines/diazomethane/recognition.html (3503 words)

	info: Diazomethane (Site not responding. Last check: 2007-10-13)
		Diazomethane is the chemical compound CH In the pure form at room temperature, it is a yellow gas, but it is almost universally used as a solution in diethyl ether.
		Diazomethane is prepared in the laboratory at mmol scale from precursors such as Diazald or N-methyl-N-nitroso-p-toluenesulfonamide and MNNG or 1-methyl-3-nitro-1-nitrosoguanidine.
		Diazomethane is liberated from a solution of MNNG in diethyl ether by addition of aqueous potassium hydroxide at low temperatures.
	www.napoli-pizza.net /Diazomethane.html (623 words)

	HHMI Lab Safety: LCSS: DIAZOMETHANE (Site not responding. Last check: 2007-10-13)
		Prolonged or repeated exposure to diazomethane can lead to sensitization of the skin and lungs, in which case asthma-like symptoms or fever may occur as the result of exposure to concentrations of diazomethane that previously caused no symptoms.
		All work with diazomethane should be conducted in a fume hood behind a safety shield, and appropriate impermeable gloves, protective clothing, and safety goggles should be worn at all times.
		Diazomethane solutions can be soaked up with a spill pillow or an absorbent material such as clay or vermiculite, placed in an appropriate container, and disposed of properly.
	www.hhmi.org /about/labsafe/lcss/lcss27.html (610 words)

	[No title] (Site not responding. Last check: 2007-10-13)
		Diazomethane is a federal hazardous air pollutant and was identified as a toxic air contaminant in April 1993 under AB 2728.
		Diazomethane is used as a methylating agent for acidic compounds (HSDB, 1991).
		Diazomethane emissions are not reported from stationary sources in California under the AB 2588 program.
	www.scorecard.org /chemical-profiles/html/diazomethane.html (396 words)

	[No title]
		Diazomethane is a useful reagent for the methylation of compounds containing a carboxylic acid group.
		A study was performed to evaluate the efficiency of conversion of benzoylecgonine to cocaine, the time necessary for the reaction and the stability of an ethereal solution of diazomethane.
		When benzoylecgonine was extracted by solid phase extraction (SPE) from urine and derivatized with diazomethane, concentrations as low as 25 ng/ml could be detected using gas-chromatography/ mass spectrometry in Full Scan mode.
	www.tiaft.org /tiaft2001/posters/p66.doc (264 words)

	Diazomethane cycloadditions to gamma-alkoxy-alpha,beta-unsaturated esters: a violation of the inside alkoxy theory?
		For this reason, we decided to study their behaviour towards diazomethane, and we wish to report that these reactions are not only completely regioselective (as already known in the literature; refs 2,3, but are often highly diastereoselective as well.
		The terminal atoms on the diazomethane moiety in the transition structure for the cycloaddition reaction are not strongly charged.
		The correlation between the amount of negative charge on the 1,3-dipole and the reaction stereoselectivity was demonstrated by previous studies.
	www.ch.ic.ac.uk /ectoc/echet96/papers/026 (2065 words)

	Diazomethane \| Technology Transfer Network Air Toxics Web site \| US EPA
		Acute (short-term) inhalation exposure of humans to diazomethane may cause irritation of the eyes, cough, wheezing, asthmatic symptoms, pulmonary edema, pneumonia, dizziness, weakness, headache, and chest pains.
		Diazomethane is used as a methylating agent for acidic compounds such as carboxylic acids, phenols, and enols.
		Acute inhalation exposure of humans to diazomethane may cause irritation of the eyes, cough, wheezing, asthmatic symptoms, pulmonary edema, pneumonia, dizziness, weakness, headache, chest pains, fever, moderate cyanosis, malaise, tremors, liver enlargement, hypersensitivity, and shock.
	www.epa.gov /ttn/atw/hlthef/diazomet.html (758 words)

	Diazald®: The Preferred Diazomethane Precursor
		Diazomethane is an extremely versatile reagent for the preparation of both carbon-carbon and carbon-heteroatom bonds.
		Additionally, diazomethane has found extensive application in the alkylation of phenols, enols, and heteroatoms such as nitrogen and sulfur.
		Due to its instability and toxicity, diazomethane is not amenable to storage or transport.
	www.sigmaaldrich.com /Area_of_Interest/Chemistry/Chemical_Synthesis/Product_Highlights/Diazald.html (390 words)

	[No title]
		The principal advances and trends in the application of diazomethane as a methylenating agent in synthetic chemistry using transition and non-transition metal compounds as catalysts are surveyed and analysed.
		The catalytic reactions of diazomethane with olefins, acethylenes, aromatic compounds, ketones, alcohols and amines are examined.
		A systematic account is given of data concerning the influence of the structure of the initial substrates and of the nature of the catalyst components on the regio- and stereo-selectivity of the reactions considered.
	www.turpion.org /php/paper.phtml?journal_id=rc&paper_id=48 (196 words)

	DIAZOMETHANE (ICSC)
		Solutions of diazomethane should not be stored (see Notes).
		Because of its toxicity and its explosive nature, diazomethane is freshly prepared in situ and used in solution of ether or dioxane.
		The relation between odour and the occupational exposure limit cannot be indicated.
	www.inchem.org /documents/icsc/icsc/eics1256.htm (453 words)

	[No title]
		Since a great deal is known about the formation of DNP amino-acids and their behaviour under various conditions of hydrolysis a logical extension and improvement of the present methods of amino-acid analysis using these compounds was the application of gas chromatography in conjunction with electron affinity spectrometry.
		The compounds were diluted in methanol to a known concentration after being taken to dryness under nitrogen to remove excess diazomethane and ether.
		At present, the use of diazomethane, with its known rapid, quantitative formation of methyl esters seems quite sufficient for the amino-acids already tested.
	www.nature.com /nature/journal/v199/n4889/ris/199141a0refs.ris (1833 words)

	Apparent Degradation of Wool by Diazomethane Solutions (Site not responding. Last check: 2007-10-13)
		In most of this earlier work, it was specifically stated that dry proteins and dry ethereal solutions of diazomethane were used.
		have shown that diazomethane acts on aqueous solutions of peptides with formation of the corresponding betaines, while serum albumin and ovalbumin in water are slowly converted to insoluble products.
		The diazomethane, prepared from nitrosomethylurea, is added to the wool over a period of several days, together with small quantities of water.
	www.nature.com /nature/journal/v171/n4352/abs/171571a0.html (215 words)

	Diazomethane Distillation Apparatus
		The mini Diazald apparatus bridges the gap between the Aldrich MNNG diazomethane generator (for preparing <1mmol of diazomethane) and the Diazald kit (for preparing ~100mmol of diazomethane).
		MNNG (1-methyl-3-nitro-1-nitrosoguanidine, 12,994-1) is probably the most convenient precursor to diazomethane because it is stable and crystalline, and generates diazomethane upon treatment with aqueous alkali.
		This apparatus is also useful for the generation of radioactive or deuterated diazomethane because it is a closed system.
	www.sigmaaldrich.com /Area_of_Interest/Equipment_Supplies__Books/Glassware_Catalog/Distillation.html (698 words)

	The Preparation and use of Diazomethane - [www.rhodium.ws]
		Diazomethane can be generated from a wide variety of precursors by adopting methods
		Small quantities of diazomethane frequently employed in routine work are generally taken from a supply of the reagent, prepared as above, which has to be stored in the cold or is generated as required using either expensive commercial microapparatus or custom-made apparatus
		The author has developed a technique which permits the rapid and safe generation of diazomethane and its simultaneous reaction with the substrate, using an apparatus which can be easily and cheaply assembled with ordinary glassware in a few minutes.
	www.erowid.org /archive/rhodium/chemistry/diazald.html (452 words)

	Documentation for Immediately Dangerous to Life or Health Concentrations (IDLHs) - 334883
		Basis for original (SCP) IDLH: The only available acute inhalation toxicity data concerning diazomethane is the statement by Patty [1963] that a 10minute exposure to 175 ppm was lethal for cats [Flury and Zernik 1931].
		ACGIH [1971] reported that the toxicity of diazomethane seems comparable to that of phosgene.
		Other animal data: It has been suggested that the toxicity of diazomethane is comparable to that of phosgene, possibly because diazomethane is a strong methylating agent [Potts et al.
	www.cdc.gov /niosh/idlh/334883.html (216 words)

	Exposure Standard (Site not responding. Last check: 2007-10-13)
		After reviewing the relevant data, the Exposure Standards Working Group is of the view that diazomethane may have carcinogenic potential to humans, based on the limited evidence from animal studies, but the available information is not adequate for making a satisfactory assessment.
		The reader is encouraged to review the section on Carcinogens in the Guidance Note on the Interpretation of Exposure Standards for Atmospheric Contaminants in the Occupational Environment, for guidance on the classification system of carcinogens.
		Schoental R and Magee PN, "Induction of squamous carcinoma of the lung and of the stomach and oesophagus by diazomethane and N-methyl-N-nitrosourethane respectively", Brit J Cancer, 16, 92-100, 1962
	www.nohsc.gov.au /OHSInformation/Databases/ExposureStandards/az/Diazomethane.htm (508 words)

	Chemistry and Industry: A rapid, safe and convenient procedure for the preparation and use of diazomethane.@ HighBeam ... (Site not responding. Last check: 2007-10-13)
		A rapid, safe and convenient procedure for the preparation and use of diazomethane.
		Diazomethane can be generated from a wide variety of precursors by adopting methods[1-5] which employ dangerous and time-consuming distillations and collection of the gaseous reagent.
		Small quantities of diazomethane frequently employed in routine work are generally taken from a supply of the reagent, prepared as above, which has to be stored in the...
	www.highbeam.com /library/doc0.asp?DOCID=1G1:9164292&refid=holomed_1 (226 words)

	Haz-Map: Occupational Exposure to Hazardous Agents
		Diazomethane is used as a methylating agent for acidic compounds.
		The only available acute inhalation toxicity data concerning diazomethane is the statement by Patty [1963] that a 10minute exposure to 175 ppm was lethal for cats [Flury and Zernik 1931].
		Therefore, the chosen IDLH is based on an analogy with phosgene, which has an IDLH of 2 ppm.
	hazmap.nlm.nih.gov /cgi-bin/hazmap_generic?tbl=TblAgents&id=396 (140 words)

	Diazomethane [factsheet]
		Acute (short-term) inhalation exposure of humans to diazomethane may cause irritation of the eyes, denudation of mucous membranes, cough, wheezing, asthmatic symptoms, pulmonary edema, fulminating pneumonia, dizziness, weakness, headache, chest pains, fever, moderate cyanosis, malaise, tremors, hepatic enlargement, hypersensitivity, shock, and death.
		* Increased incidences of pulmonary adenomas have been observed in rats and mice exposed to diazomethane by inhalation and in dermally exposed mice.
		* Diazomethane is used as a methylating agent for acidic compounds such as carboxylic acids, phenols, and enols.
	www.lakes-environmental.com /toxic/DIAZOMETHANE.HTML (567 words)

	DIAZOMETHANE
		Solutions of diazomethane should not be stored (see Notes).
		Because of its toxicity and its explosive nature, diazomethane is freshly prepared in situ and used in solution of ether or dioxane.
		The symptoms of lung oedema often do not become manifest until a few hours have passed and they are aggravated by physical effort.
	www.itcilo.org /english/actrav/telearn/osh/ic/334883.htm (475 words)

	Inter-American Photochemical Society Newsletter, Vol (Site not responding. Last check: 2007-10-13)
		Eagerly I went to the library and found that an Organic Synthesis prep involving the reaction of diazomethane with pyruvic acid, which was available in the chemical stores room, should do the trick.
		The ground glass can cause the diazomethane to decompose uncontrollably and set off an explosion!!!" John was a real scholar and knew all this stuff.
		Although I didn't use the word then, I was thrilled at the possibility of skating on the edge of the paradigm, recognizing the value of identifying and attacking problems that were good science and could also attract the community's attention at the same time.
	www.tulane.edu /~murthy/turroown.html (8937 words)

	W0376: Structure Analysis of Reaction Intermediates Trapped in Crystalline Lattice
		The crystal structure after irradiation indicated that a dinitrogen molecule and the hexachlorodiphenylcarbene were produced in the crystalline lattice.
		The salient feature of the carbene structure is the carbenic angle of the central carbon (142(2)°), which is wider by about 15° than the corresponding angle of the original diazomethane.
		When the crystal of 2-azidobiphenyl was irradiated with light (>420 nm) for 5 h, the crystal color changed from colorless to brown with retention of the single crystal form.
	www.hwi.buffalo.edu /ACA/ACA01/abstracts/text/W0376.html (254 words)

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