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Topic: Dehydrohalogenation

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	Process and catalyst for the dehydrohalogenation of halogenated hydrocarbons - Patent 4816609
		What is needed is an efficient dehydrohalogenation process that would avoid the waste disposal and halogen loss problems of prior methods by providing a means for safely and economically removing any salt or hydrogen halide produced by the dehydrohalogenation reaction.
		It has surprisingly been found that such a catalyst does not rapidly deactivate in typical dehydrohalogenation reactions when the catalyst is used in the presence of an alkanol and oxygen.
		The process of present invention comprises contacting a halogenated hydrocarbon and an alkanol in the presence of the catalyst described hereinbefore under reaction conditions sufficient to form the corresponding unsaturated halohydrocarbon or unsaturated hydrocarbon.
	www.freepatentsonline.com /4816609.html (2138 words)

	E2 Elimination Reaction
		This reaction illustrates the base-induced dehydrohalogenation of alkyl halides with strong base and is used extensively for the preparation of alkenes.
		Base-induced elimination (dehydrohalogenation) of alkyl halides is a general reaction and is an excellent method for preparing alkenes.
		Dehydrohalogenation of alkyl halides in the presence of strong base (E2) is often accompanied by the formation of substitution (S
	www.owlnet.rice.edu /~chem215/ER/index.html (1207 words)

	US PATENT SUBCLASS 570 / 155-- .~.~.~.~ By dehalogenation or dehydrohalogenation of adjacent carbon ... (Site not responding. Last check: 2007-10-17)
		.~.~.~.~ By dehalogenation or dehydrohalogenation of adjacent carbon atoms in a compound
		.~.~.~.~ By dehalogenation or dehydrohalogenation of adjacent carbon atoms in a compound {1}
		By dehalogenation or dehydrohalogenation of adjacent carbon atoms in a compound:
	www.patentec.com /data/class/defs/570/155.html (87 words)

	Fluorine induced dehydrohalogenation process - Patent 4782121
		It is one object of the present procedure to therefore provide a preliminary step to assist in conducting the dehydrohalogenation step in the presence of a strong base (EDA is typical) and to obtain controllable surface penetration and controllable conversion to selected ranges of electrical conductivity.
		To further change the electrical conductivity, temperature control during the dehydrohalogenation step would appear to increase the amount of chlorine removed without seriously impacting the fluoride in the polymer.
		Thus, one of the process control factors is the temperature of the base and the duration of the exposure to the base.
	www.freepatentsonline.com /4782121.html (2087 words)

	E2 Reactions of Alkyl Halides
		Dehydrohalogenation of Primary Halides:E2 The removal of a Hydrogen atom and a halogen atom is called Dehydrohalogenation.
		With any dehydrohalogenation a relatively strong base is required to pull a Hydrogen off of a carbon adjacent to the carbon bonded to the halogen.
		Such adjacent carbons are referred to as beta carbons and the hydrogens attached to these carbons are referred to as beta hydrogens.
	members.aol.com /logan20/e2.html (1176 words)

	Chem351L - Dehydrohalogenation of Alkyl Halides (Site not responding. Last check: 2007-10-17)
		The purpose of this lab is to investigate the influence of base in E2 eliminations.
		Your teaching assistant will assign you either potassium hydroxide or potassium t-butoxide to use as the base for the dehydrohalogenation of 2-bromo-2-methyl butane.
		You might be confused by the two concepts of yield in the dehydrohalogenation reaction.
	ice.chem.umbc.edu.cob-web.org:8888 /Chem351l/dehydrohal_index.html (796 words)

	F13. Ab Initio Kinetics of the Thermal Dehydrohalogenation of Alkyl Halides (Site not responding. Last check: 2007-10-17)
		Ab Initio Kinetics of the Thermal Dehydrohalogenation of Alkyl Halides
		High-level calculations of the unimolecular 1,2-dehydrohalogenation of small alkyl halides were performed (1) to test the quantitative accuracy of ab initio kinetics predictions and (2) to explain the observed correlation of reaction rate with the stability of the corresponding alkyl cation.
		Population analysis shows that there is substantial carbon-halogen charge separation in the transition state, explaining the prior observation that rapid reactions are associated with low heterolytic C-X bond strengths.
	www.cstl.nist.gov /div838/kinet_conf/agenda/f_session/f13/f13.html (154 words)

	Dehydrohalogenation - EMOC
		Alkynes can be prepared from either vicinal (attached at adjacent atoms) or geminal (attached at the same atom) dihalides with appropriate hydrogen atoms.
		Stronger bases are generally used in dehydrohalogenation to form alkynes than in forming alkenes.
		The mechanism which occurs is dependent on the strength of the base used to carry out the reaction.
	www.chem.memphis.edu /parrill/EMOC/roadmap/dehydhal.html (488 words)

	Dehydrohalogenation by the E1 Mechanism (via CobWeb/3.1 planetlab2.tamu.edu) (Site not responding. Last check: 2007-10-17)
		Dehydrohalogenation by the E1 Mechanism (via CobWeb/3.1 planetlab2.tamu.edu)
		E1 dehydrohalogenation usually takes place in a good ionizing solvent such as an alcohol or water, without a strong nucleophile or base to force 2nd order kinetics.
		This reaction is generally accompanied by SN1 substitution because the nucleophilic solvent can also attack the carbocation directly.
	www.albany.edu.cob-web.org:8888 /faculty/musah/achm216a/presentations/chapter7/tsld026.htm (63 words)

	Heinz Koch, Professor
		Koch and G. Lodder "Isotope and Element Effects Associated with Hydron-Transfer Steps During Methoxide-Promoted Dehydrohalogenation Reactions" 3rd Latin American Conference on Physical Organic Chemistry, Florianopolis, Brazil, 10-14 April, 1995.
		Nichols, M. Mishima, Mustinar, H. Zuilhof and G. Lodder "Proton Transfer Between Carbon Acids and Methoxide: Further Studies in the Gas Phase, by Ab Initio Molecular Orbital Calculations and in Mehtanol" 8th Kyushu International Symposium on Physical Organic Chemistry, Kyushu University, Fukuoka, Japan, 28 September-1 October, 1999.
		Sardina and H. Koch "The Effect of -Halogens on Proton-Transfer Associated with Methoxide-Promoted Dehydrohalogenation Reactions" XXth National Conference on Undergraduate Research, Union College, 20-22 April, 1995.
	www.ithaca.edu /chemistry/heinz/heinz_pubs.html (1328 words)

	(WO/1988/007031) PROTIC SOLVENT IN A DEHYDROHALOGENATION PROCESS, THE PRODUCT OBTAINED THEREFROM AND LUBRICANT ... (Site not responding. Last check: 2007-10-17)
		The process involves dehydrohalogenation of an olefin/sulfur halide complex by contacting the complex with a protic solvent in the absence of any metal ion.
		The process allows for the solvolytic dehydrohalogenation of the complex.
		The sulfurized olefin product obtained is isolated and may be subjected to further processing to remove any remaining halides.
	www.wipo.int /pctdb/en/wo.jsp?WO=1988/07031 (257 words)

	2000 Program
		One method commonly employed to generate nitrile oxides is by converting an aldoxime into its corresponding hydroxamic acid halide with the use of a halogenating agent.
		Subsequent base catalyzed dehydrohalogenation of the hydroxamic acid halide generates the desired nitrile oxide which is trapped by an olefin.
		This two-step process is typically performed in one-pot, may be easily scaled-up, and can be performed cheaply utilizing household bleach as the halogenating reagent, readily available water insoluble aldoximes, and unsaturated alkyl esters.
	www.aaic.org /00progrm.htm (11329 words)

	FAST-ACT: Effectiveness against toxic industrial chemical and chemical warfare agents
		FAST-ACT destroys chemical warfare agents through hydrolysis and dehydrohalogenation.
		Nerve agents (VX and GD) are hydrolyzed with the formation of surface bound metal phosphonates.
		The dehydrohalogenation products, vinyl and divinyl HD are not bound to the surface and thus remain volatile.
	www.fast-act.com /effective.asp (643 words)

	cis/trans dehydrohalogenation products
		I was wondering how come we have 2 products when we dehydrohalogenate cis-1-bromo-2-methylcyclohexane and we have only one product if we dehydrohalogenate trans-1-bromo-2-methylcyclohexane?
		I thought that it wouldn't matter if the reactant is cis or trans...
		I assume that saying this is a dehydrohalogenation reaction, the "requirements" for Elimination reaction is being used......so that contradicts the other thought I have which pertains to an unhindered base possibly going through a possible Substitution reaction; thus giving cis 2 products (or maybe 3), and trans 1 product (or maybe 2)
	www.chemicalforums.com /index.php?topic=1720.msg7391 (877 words)

	[No title]
		Predict the elimination product in the E2 dehydrohalogenation of 2-bromo-2-methylpropane by NaOCH3 in CH3OH.
		Predict the elimination products in the E2 dehydrohalogenation of 2-bromo-2-methylbutane by NaOCH3 in CH3OH.
		Predict the elimination products in the E2 dehydrohalogenation of cis-1-bromo-2-methylcyclohexane by NaOCH2CH3 in CH3CH2OH.
	www.sunybroome.edu /~wovkulich_m/CHM245/CHM245-U9-Worksheet.doc (436 words)

	Class Schedule for Class 570 ORGANIC COMPOUNDS -- PART OF THE CLASS 532-570 SERIES
		Decreasing molecular weight of polymer of indeterminate structure
		Decreasing the number of carbon atoms in the compound
		Dehalogenation or dehydrohalogenation with halogenation in separate zones
	www.uspto.gov /go/classification/uspc570/sched570.htm (666 words)

	[No title]
		This catalytic activity has been found to increase upon conversion of the metal oxide catalyst to chloride.
		Experiments have been expanded in scope to investigate compressed metal oxide samples, 1-bromobutane catalytic dehydrohalogenation, and surface area and pore structure analysis, as well as mechanistic studies.
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	www.engg.ksu.edu /HSRC/abs35.doc (144 words)

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