Iodoacetates iodides

Methylene iodide [75-11-6], CH2I2, also known as diio dome thane, mol wt 267.87, 94.76% I, mp 6.0°C, and bp 181°C, is a very heavy colorless Hquid. It has a density of 3.325 g/mL at 20°C and a refractive index of 1.7538 at 4°C. It darkens in contact with air, moisture, and light. Its solubiHty in water is 1.42 g/100 g H2O at 20°C it is soluble in alcohol, chloroform, ben2ene, and ether. Methylene iodide is prepared by reaction of sodium arsenite and iodoform with sodium hydroxide reaction of iodine, sodium ethoxide, and hydroiodic acid on iodoform the oxidation of iodoacetic acid with potassium persulfate and by reaction of potassium iodide and methylene chloride (124,125). Diiodoform is used for determining the density and refractive index of minerals. It is also used as a starting material in the manufacture of x-ray contrast media and other synthetic pharmaceuticals (qv). 

Butenolides.1 When activated by silver trifluoroacetate, this furan is alkylated by primary alkyl iodides or ethyl a-iodoacetate to give 4-alkyl-2-butenolides (2) in 60-80% yield. 

Three common methods of production are described in the literature the action of iodine,1 sodium ethylate,2 or hydriodic acid 3 on iodoform. The last of these three methods has been worked out in more detail and is the one generally recommended for the preparation of methylene iodide in the laboratory. In addition, methylene iodide has been produced by the action of iodine on diazomethane 4 and by electrolysis of iodoacetic acid.5 It may also be made by the action of potassium iodide upon methylene chloride.Sa... 

The use of iodoacetic acid as an aryl radical trapping agent has confirmed the intermediacy of aryl radicals in some hydrodediazoniation reactions, whether these are initiated or not.4 Spontaneous hydrodediazoniation of aryldiazonium fluoroborates occurs in warm dimethylformamide (DMF). Detailed study5 of the conversion of the 4-nitro derivative into nitrobenzene indicates a homolytic mechanism in which H-atom abstraction occurs from both sites in DMF with a formyl methyl preference of 3.5 1.0. High yields of mixed perfluorinated biaryls may be obtained by the catalytic dediazoniation of pentafluorobenzenediazonium ions in acetonitrile containing aromatic substrates and small amounts of iodide salts. The catalytic role of iodide and the isomeric product distributions indicate that arylation proceeds through the pentafluorophenyl radical in an efficient homolytic chain process.6... 

Intramolecular cyclization of the chiral oxime ether 993 in the presence of isopropyl iodide and triethylborane affords the 3,4,5-trisubstituted tetrahydropyran-2-one 994 in poor yield but with good diastereoselectivity (Equation 388) <2003JOG5618>. Similarly, a triethylborane-induced atom transfer radical cyclization of 3-butenyl 2-iodoacetate leads to 4-(iodomethyl)tetrahydropyran-2-one. Higher yields are achieved when conducting the reaction at lower concentrations (Equation 389) <2000JA11041 >. 

This reaction comprises firstly of SH2 reaction on the iodine atom of ethyl iodoacetate by an ethyl radical, formed from triethylborane and molecular oxygen, to form a more stable Chester radical and ethyl iodide. Electrophilic addition of the a-ester radical to electron-rich aromatics (36) forms an adduct radical, and finally abstraction of a hydrogen atom from the adduct by the ethyl radical or oxidation by molecular oxygen generates ethyl arylacetate (37), as shown in eq. 5.20. Here, a nucleophilic ethyl radical does not react with electron-rich aromatics (36), while only an electrophilic a-ester radical reacts with electron-rich aromatics via SOMO-HOMO interaction. 

Dichloroindium hydride HlnCla, prepared from indium(m) chloride and DIBAL-H, works as a radical mediator. This compound reduces aryl iodides and bromides in the presence of Et3B as a radical initiator. Reduction of iodoacetals provides cyclized products in good yields (Equation (99)).385 Only a catalytic amount of InCl3 is necessary for complete consumption of the starting compound with stoichiometric DIBAL-H as a hydride source (Equation (100)). 

Iodoacetic acid [64-69-7] (ICH2COOH), mol wt 185.95, C2H3I02, is commercially available. The colorless, white crystals (mp 83 °C) are unstable upon heating. It has a K of 7,1 x 10-4. Iodoacetic acid is soluble in hot water and alcohol, and slightly soluble in ethyl ether. Iodoacetic acid can be reduced with kydroiodic acid at 85°C to give acetic acid and iodine (57). Iodoacetic acid cannot be prepared by the direct iodination of acetic acid (58), but has been prepared by iodination of acetic anhydride in the presence of sulfuric or nitric acid (59). Iodoacetic acid can also be prepared by reaction of chloroacetic or bromoacetic acid with sodium or potassium iodide (60). 

This substance cannot be prepared, like the two preceding, by esterification of iodoacetic acid with ethyl alcohol. It is necessary to start with ethyl chloroacetate or bromoacetate, both of which react with potassium iodide to form the iodo-compound,... 

Diorgano tellurium compounds have been reacted with methyl iodide (Vol. IX, p 1076), ethyl iodide ethyl iodoacetate, cyclohexyl iodide , methyl bromide, allyl bromide , benzyl bromide , bromoacetone , bromomethyl phenyl ketone , a-bromocarboxylic acids , a-bromocarboxylic acid esters , methyl chloride, and benzyl chloride . 

As is true for all kinases, Mg is an obligate activating ion that forms complexes with ATP and ADP. The optimal concentration range for Mg is quite narrow, and excess Mg is inhibitory. Many metal ions, such as Mn, Ca , and Cu , inhibit enzyme activity, as do iodoacetate and other suhhydryl-binding reagents. Activity is inhibited by excess ADP and by citrate, fluoride, nitrate, acetate, iodide, bromide, malonate, and L-thyroxine. Urate and cystine are... 

Using supported ditin compounds, it is possible to promote free radical addition of organic iodides to ttiple bonds and atom transfer cyclization of e-unsaturated iodoacetates or iodoamides using UV irradiation. In this latter case, tin contamination was found to be 5-34 ppm using 0.1 eq. of ditin reagent, and recycling of the tin reagent was also possible. 

Triethylborane is also an excellent initiator for intramolecular iodine atom transfer reactions. For example, cyclisation of the propargyl a-iodoacetal depicted in Scheme 6.5 gives the corresponding bicyclic vinyl iodide in high yield.10 Allyliodoacetamides (Scheme 6.5) and allyl iodoacetates (Scheme 6.5) cyclise cleanly under Et3B-02 initiation. In the case of the ester, the reaction has to be run in refluxing benzene in order to allow Z/E-ester isomerisation prior to... 

A method is presented to determine organomeicury compounds in aquatic sediments. The compounds are liberated from the sediment by addition of sulfuric acid and then immediately converted to the iodide form by iodoacetic acid in a closed vial. The liberated methylmercmy iodide is then Headspace-injected on a gaschromatograph and detected with a Microwave-induced-plasma detector. Analysis of 1 sample takes less than 15 minutes. Detection limit equals 0.014 p g methylmercury/g sediment. 

Ethyl bromoacetate Chloroacetone Xylyl bromide Benzyl bromide Bromomethyl ethyl ketone Bromoacetone Iodoacetone Ethyl iodoacetate Benzyl iodide Acrolein... 

Tetrahydrofuran derivatives. With the EtMgBr-neopentyl iodide system in THF, the solvent becomes iodinated at C-2 (free radical process) and 2-aryltetrahydrofurans are obtained on addition of EtI and EtMgBr to arylmagnesium halides in THP. Radical cyclization of allyl P-iodoacetals is induced by EtMgBr in DME. ... 

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