Iodine reagents

Ethyl acrylate is used in approximately 50% molar excess over the expensive, limiting reagent, iodine. Use of an equimolar amount results in a lower yield (85%). The checkers distilled the reagent at 20° (39 mm.) prior to use. 

Reagent iodine vapour phosphomolybdic acid fluorescein/bromine sulphuric acid ninhydrin or isotin 2,4 -dinitropheny lhy drazine H2S water, diphenylcarbazide or... 

Aryl iodidesThe reagent iodinates aromatic compounds at 25° in reasonable yields (50-85%). 

By varying the amount of the reagents, iodine in DMSO720 or [bis(trifluoroacetoxy) iodo]benzene721 selectively oxidizes one or both triple bonds in aromatic diynes. 

Monosubstitution of the free amine may be achieved by using a less reactive electrophile. Thus aniline and o-toluidine may be mono-iodinated (Expt 6.60) by treatment with iodine (in the presence of sodium hydrogen carbonate or calcium carbonate to remove the liberated hydrogen iodide), the substituent entering the position para to the amino group. Direct iodination can also be effected by using the more powerfully electrophilic reagent, iodine monochloride... 

Cyclobutanone 15 is available, and also very electrophilic, so addition of the vinyl Grignard and dehydration with the rather unusual reagent iodine gave the diene 13. This diene will be used in a Diels-Alder reaction in chapter 17. 

Chlorine tends to bleach the reagent. Iodine forms the red-violet coloured iodo-eosin and hence must be absent. If the bromide is oxidized to free bromine by heating with lead dioxide and acetic acid, practically no chlorine is simultaneously evolved from chlorides, and hence the test may be conducted in the presence of chlorides. 

Vinblastine and vincristine were detected with Dragendorff s reagent, iodine/potassium iodide, and ceruric ammonium sulfate as well as by fluorescence (6). Jaffrey reagent was applied to purified vindoline on chromatograms... 

In the endothermic HI reaction, hydriodic acid Hix from Bunsen reaction is concentrated in a number of steps and the resulting hydrogen iodide concentrate is decomposed into reagent iodine and product hydrogen gas. The HI reaction steps appear to have the largest room for process improvement, for which several innovative process techniques have been incorporated in the present flowsheet. The HI concentration steps combine electro-electrodialysis cell and carbonized osmosis membrane to reduce excess iodine and water prior to final distillation. An iodine absorber is integrated into the HI decomposer to improve decomposition ratio in a newly proposed Co- regenerated process ... 

A. Iodine The universal detection reagent iodine is used either as a 1% alcoholic spray, or the plate is placed in a closed jar or tank containing iodine crystals. The iodine vapor dissolves in, or forms weak charge-transfer complexes with organic compounds, which show up as brown spots on a pale yellow background within a few minutes. After marking zones for future reference, exposure of the plate to air causes the iodine to sublimate and the spots to fade, after which the plate can be sprayed with another reagent or the solute can be eluted from the plate for further analysis. 

ALKENES Allyl dimethyldithiocarbamate. Bis(t -cyclopentadienyl)niobium trihydride. Cyanogen bromide. Di-n-butylcopperlithium. a,o-Dichloromethyl methyl ether. 2,3-Dimethyl-2-butylborane. N,N-Dimethyl dichlorophosphoramide. Diphenyl diselenide. Di-n-propylcopperlithium. Ferric chloride. Grignard reagents. Iodine. Lithium phenylethynolate. Lithium 2,2,6,6-tetramethylpiperidide. Methyl iodide. o-Nitro-phenyl selenocyanate. Propargyl bromide. rra s-l-Propenyllithium. Selenium. Tetrakis(triphenylphosphine)palladium. Titanium(IH) chloride. Titanium trichloride-Lithium aluminum hydride. p-Toluenesulfonylhydrazine. Triphenylphosphine. Vinyl-copper reagents. Vinyllithium. Zinc. 

Schiff s reagent Schweitzer s reagent Iodine solution Tannic acid (10% soln.)... 

Procedures based on the reaction of phenelzine sulfate with iodine in bicarbonate solution (2) and in sodium hydroxide (16) and with bromate and bromide in acid solution (16) with subsequent titration of excess reagent (iodine or bromide converted to iodine) in acid solution with thiosulfate have been reported. 

Sodium iodide Tetrabutyl ammonium iodide reagent, iodine testing presence of chlorine Thallium (I) sulfate reagent, ion-pair Laurtrimonium bromide reagent, iron Thioglycolic acid... 

Both, Y and Y can be cleaved to pUp (and unidentified peptides) by snake venom 3exonuclease. These results exclude phosphoesters like Ser-P or phosphoramidates like nucleotidyl-(5 -N )-Arg or nucleotidyl-(5 -N )-lys as the bond between VPg and ENA. (ii) VPg linked to genome ENA can be iodinated by the Bolton and Hunter reagent ( iodinated 3-(4 hydroxyphenyl) proprionic acid... 

Synthetic strategy lodonium-promoted 5-endo-dig carbocycUzation of aUcynes and active methlene compounds Catalysts/reagents Iodine... 

---