Author Topic: 2009 Reference and Translation Requests (Read 3039 times)

heisenberg · « **Reply #140 on:** December 09, 2009, 03:29:03 PM »

Studies on oxidation of ergot alkaloids: oxidation and desaturation of dihydrolysergol—stereochemical requirements
Radek Gažáka, Vladimír K?ena, Petr Sedmeraa, Daniele Passarellab, Michaela Novotnáa and Bruno Danielib
Tetrahedron Volume 63, Issue 42, 15 October 2007, Pages 10466-10478
DOI:10.1016/j.tet.2007.07.099

Abstract

A new method for the oxidation of ergoline alcohols to aldehydes was found (TFFA–DMSO, ?78 °C, then DIPEA). Structural features of ergolines required for successful C7–C8 double bond introduction via Polonovski–Potier reaction of respective 6-N-oxides were defined and experimentally confirmed: (i) the presence of electron-withdrawing group at C-8; (ii) trans-diaxial orientation of N6–O and C7–H bonds (both requirements are fulfilled for dihydrolyserg-17-al and its 2,4-dinitrophenyl hydrazone prepared in this work).

heisenberg · « **Reply #141 on:** December 09, 2009, 04:20:42 PM »

THE ERGOT ALKALOIDS. X.* ON ERGOTAMINE AND ERGOCLAVINE
WALTER A. JACOBS, LYMAN C. CRAIG
J. Org. Chem., 1936, 01 (3), pp 245–253
DOI: 10.1021/jo01232a003

Abstract

Ergotinine, for which the empirical formula C35H39N5O5 was derived by Barger and Carr, has been shown by us to be composed of lysergic acid, ammonia, isobutyrylformic acid, d-proline, and l-phenylalanine, joined in amide linkages, a fact in agreement with such a formulation. Similarly, the simpler ergot alkaloid, ergometrine, now accepted as having the formula C19H23N3O2, we have shown to yield lysergic acid and 2-amino-propan-1-ol on hydrolysis, and is therefore the hydroxyisopropylamide of lysergic acid. Preliminary notes have also been presented on the results of similar hydrolytic studies with ergotamine and ergoclavine. Our examination, from this standpoint, of these alkaloids as well as that of ergotoxine has since been carried further.

java · « **Reply #142 on:** December 10, 2009, 02:28:51 AM »

Zur C-17-Oxidation von Clavinalkaloiden mit primärer alkoholischer Hydroxylgruppe
K. Mayer, Prof. Dr. E. Eich
Archiv der PharmazieVolume 308 Issue 11, Pages 819 - 824

java · « **Reply #143 on:** December 10, 2009, 02:44:32 AM »

Hydroamination of cinnamyl alcohol using lithium amides
Conor S. Barrya and Nigel S. Simpkins,
[color]green]Tetrahedron Letters[/color] Volume 48, Issue 46, 12 November 2007, Pages 8192-8195

Abstract
Hydroamination of cinnamyl alcohol is possible by reaction with lithium amides derived from primary or cyclic secondary amines.

Graphical abstract

Keywords: Aminoalcohol; Hydroamination; Lithium amide; Cinnamyl alcohol

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Heteropoly acids: a green and efficient heterogeneous Brønsted acidic catalyst for the intermolecular hydroamination of olefins
Lei Yanga, Li-Wen Xua, b, , and Chun-Gu Xiaa,
Tetrahedron Letters Volume 49, Issue 18, 28 April 2008, Pages 2882-2885

Abstract
Intermolecular hydroamination of non-activated olefins with amides and benzyl carbamate proceeds efficiently in the presence of environmentally benign silicotungstic acid (HSiW) catalyst under mild conditions in air to afford addition products in good to excellent yields.

Graphical abstract

Keywords: Heteropoly acids; Intermolecular hydroamination; Amides; Olefins

Quantum Dude · « **Reply #144 on:** December 10, 2009, 02:50:17 PM »

The preparation of carboxylic amides from aldehydes by oxidation
Norman W. Gilman

J. Chem. Soc. D, 1971, 733 - 734,
DOI: 10.1039/C29710000733

New methods for the oxidation of aldehydes to carboxylic acids and esters
Elias J. Corey, Norman W. Gilman, B. E. Ganem

J. Am. Chem. Soc., 1968, 90 (20), pp 5616–5617
DOI: 10.1021/ja01022a059
Publication Date: September 1968

heisenberg · « **Reply #145 on:** December 10, 2009, 03:29:12 PM »

Leaching platinum-group metals in a sulfuric acid/chloride solution
M. H. H. Mahmoud
Journal of the Minerals, Metals and Materials Society Volume 55(4) (2003) pp.37-40
DOI: 10.1007/s11837-003-0086-y

Abstract

A leaching process was established based on the ability of platinum-group metals to form stable chloro-complexes in acidic chloride solutions. Industrial catalyst losses were examined for the recovery of platinum, palladium, and rhodium by leaching with a mixture of sulfuric acid and sodium chloride to avoid using aqua regia or autoclave conditions. Extraction of platinum and rhodium in 60% H2SO4 at 135°C steadily increased with increasing NaCl concentrations reaching 95% and 85%, respectively, at 0.1 M NaCl after two hours. By comparison, palladium was dissolved more quickly but also reached 85% under the same conditions. Extraction of each metal increased with temperatures up to 125°C but plateaued at higher temperatures. Similar behavior was observed with increasing H2SO4 concentrations up to 60%. More than 99% extraction of each metal was obtained after ten hours using 0.1 M NaCl and 60% H2SO4 at 125°C.

Improved and selective platinum recovery from spent ?-alumina supported catalysts using pretreated anionic ion exchange resin
K. Shams and F. Goodarzi
Journal of Hazardous Materials Volume 131(1-3) (2006) pp.229-237
DOI: 10.1016/j.jhazmat.2005.09.044

Abstract

Improved and selective recovery of platinum from a spent dehydrogenation platinum ?-alumina supported catalyst using a strong basic ion exchange resin is reported. Platinum and other precious metal group (PMG) complexes are leached using concentrated hydrochloric acid along with about 0.20 vol.% nitric acid as an oxidizing agent from de-coked and crushed spent catalyst. Effects of hydrochloric acid concentration, time, and temperature in leaching stage are investigated. The strong basic anionic resin is treated by sodium hydroxide solution to replace chloride anion by hydroxyl group ion. The supernatant of the leaching process is passed through a fixed column of hydroxylated strong base anionic resin. The treated resin on which the platinum complex is adsorbed is dried and burned in an oxidizing atmosphere at 750–800 °C. The recovered gray metallic powder is mainly platinum. Results compared with those obtained from untreated anionic resin show that adsorption of platinum complexes onto the treated anionic resin is more selective and the yield of separation is considerably improved. The breakthrough curves of the pretreated anion exchanger and that of untreated exchange resin reveals that the capacity of the hyroxilated resin is decreased by about 14%. These breakthrough curves can be used for calculation of height of a practical exchange plate (HPEP) for design purposes.

A SEM-EDS study of new and used automotive catalysts
T.N. Angelidis and S.A. Sklavounos
Applied Catalysis A: General Volume 133(1) (1995) pp.121-132
DOI: 10.1016/0926-860X(95)00165-4

Abstract

Automotive catalyst deactivation by inorganic contaminants orginating in engine oil and fuel is discussed. Scanning electron microscopy images and energy dispersive spectroscopy analysis were used to characterize the variation of contaminant relative concentrations in various types of used monolithic catalysts. The major contaminants were calcium, phosphorus, sulphur, lead, iron and zinc. All contaminants seems to have a cumulative time dependent effect, acting more as foulants than as poisons. Valuable information about the washcoat composition were derived. A preliminary acetic acid leaching test showed that a significant quantity of the contaminants may be easily removed from the catalyst surface.

no1uno · « **Reply #146 on:** December 11, 2009, 07:18:28 AM »

Righto, I would like 2 more references, these thanks:

Preparation of D-Arabinose from D-Glucose with Hypochlorite

Roy L. Whistler, Richard Schweiger

J. Am. Chem. Soc., 1959, 81 (19), pp 5190–5192
DOI: 10.1021/ja01528a042

Abstract

D-Arabinose can be prepared from D-glucose by a two-stage, but single batch, hypochlorite oxidation. D-Glucose is first converted to D-gluconate by oxidation at pH 11 with 3 moles of hypochlorite per mole of sugar. In about 20 hr. the pH is adjusted to 4.5-5.0 and about 1.4 moles of hypochlorite per mole of original glucose is added. The D-gluconate is further oxidized to D-arabinose, which can be isolated in 35% crystalline yield from the reaction products after their treatment with anion and cation exchange resins and concentration to a small volume.

Improvements in the Preparation of d-Arabinose from Calcium Gluconate

R. C. Hockett, C. S. Hudson

J. Am. Chem. Soc., 1934, 56(7), pp 1632–1633
DOI: 10.1021/ja01322a059

Abstract

Arabinose is unique amongst sugars in that both its stereochemical isomers are relatively easy to obtain. The l-form is a constituent of many plant gums, while the d-form may be prepared from d-glucose by degradation. In many researches involving the use of this sugar it is a matter of indifference which isomer is employed; thus the choice between them will be determined in such cases only by their relative availability in a pure condition. A method of preparation therefore is to be judged according to the cheapness and accessability of the raw material and the ease and rapidity with which it can be converted into practical quantities of a highly pure product, rather than on the basis of crude impure sugar.

Here are two references I already have so I'll provide them here:

Studies on Amino-hexoses. I. A New Method for Preparing Crystalline D-Arabinose

Yoshio MATSUSHIMA

Abstract

The preparation of D-arabinose has been dependant on the methods of Ruff, Wohl-Zemplen or of Weerman, all of which consisted of degrading D-glucose.

The author took up D-glucosamine as a starting material which is much more accessible in this country. The author's aim was that D-glucosamine; a sort of a-amino-aldehyde, would undergo an oxidation analogous to the oxidation of a-amino-acids as exhibited by Dakin and Langheld who obtained aldehydes with one carbon atom less than the starting amino-acids. In fact, Herbst has oxidized glucosamine with chloramine-T (p-toluenesodium sulfonchloramide) and has obtained D-arabinose in the form of benzyl-phenylhydrazone in 20-40% yields. He concludes that the reaction proceeds as below from the fact that the intermediate product, glucosaminic acid, is also oxidized by chloramine-T giving D-arabinose in about 40% yield.

Preparation of D-Arabinose-5-C¹⁴ from D-Glucose-6-C¹⁴

Horace S. Isbell, Nancy B. Holt, and Harriet L. Frush

Journal of Research of the Nat. Bereau of Standards
Vol.57(2) (1956) Research Paper 2697

Abstract

D-Arabinose-5-C14 has been prepared from D-Glucose-6-C¹⁴ by bromine oxidation to D-Gluconic Acid-6-C-¹⁴, followed by Ruff Degradation of the Calcium salt. The over-all yield, 58%, was obtained without separation of any intermediate products.

java · « **Reply #147 on:** December 11, 2009, 02:32:54 PM »

New nitric oxide-releasing zwitterions derived from polyamines
Joseph A. Hrabie, John R. Klose, David A. Wink, Larry K. Keefer
J. Org. Chem. 58 (6): 1472–1476, 1993

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Cyclopropanes from an Easily Prepared, Highly Active Zinc-Copper Couple, Dibromomethane, and Olefins
Eugene LeGoff
J. Org. Chem. 29: 2048, 1964

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java · « **Reply #148 on:** December 12, 2009, 02:54:12 PM »

Hydrolysis of Nitrosylsulfuric Acid
P. P. Kim1, G. V. Pastukhova1 and A. A. Peretrutov
Journal Russian Journal of Applied Chemistry Volume 74, Number 1 / January, 2001, Pages 167-169

java · « **Reply #149 on:** December 12, 2009, 03:26:54 PM »

Zinc/Copper Couple". Encyclopedia of Reagents for Organic Synthesis
Scott D. Rychnovsky, Jay P. Powers
(2001). ". doi:10.1002/047084289X.rz011

java · « **Reply #150 on:** December 13, 2009, 01:02:24 PM »

Preparation of D-Arabinose from D-Glucose with Hypochlorite
Roy L. Whistler, Richard Schweiger
J. Am. Chem. Soc. 1959, 81 (19), pp 5190–5192

Abstract
D-Arabinose can be prepared from D-glucose by a two-stage, but single batch, hypochlorite oxidation. D-Glucose is first converted to D-gluconate by oxidation at pH 11 with 3 moles of hypochlorite per mole of sugar. In about 20 hr. the pH is adjusted to 4.5-5.0 and about 1.4 moles of hypochlorite per mole of original glucose is added. The D-gluconate is further oxidized to D-arabinose, which can be isolated in 35% crystalline yield from the reaction products after their treatment with anion and cation exchange resins and concentration to a small volume.

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Improvements in the Preparation of d-Arabinose from Calcium Gluconate
R. C. Hockett, C. S. Hudson
J. Am. Chem. Soc. 1934, 56(7), pp 1632–1633

Abstract
Arabinose is unique amongst sugars in that both its stereochemical isomers are relatively easy to obtain. The l-form is a constituent of many plant gums, while the d-form may be prepared from d-glucose by degradation. In many researches involving the use of this sugar it is a matter of indifference which isomer is employed; thus the choice between them will be determined in such cases only by their relative availability in a pure condition. A method of preparation therefore is to be judged according to the cheapness and accessability of the raw material and the ease and rapidity with which it can be converted into practical quantities of a highly pure product, rather than on the basis of crude impure sugar.

java · « **Reply #151 on:** December 13, 2009, 01:17:21 PM »

A Synthesis of Pseudoephedrine
Roy G. Bossert, Wallace R. Brode
J. Am. Chem. Soc. 1934, 56 (1), pp 165–166

Abstract
The synthesis of pseudoephedrine as described in this paper is based on the same methods as have been described previously for B-ethoxy amines with subsequent splitting of the ether to yield the amino alcohol.

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Tropanone and its Homologs
LeRoy C. Keagle, Walter H. Hartung
J. Am. Chem. Soc. 1946, 68(, pp.1608–1610

Abstract
Robinson's synthesis of tropanone form acetone, methylamine and succinaldehyde, characterized by Willstatter as "von bewundernswerter Eleganz" stimulated speculation on the possible synthesis of atropine and other products in plant tissue. The disccussion, well summarized by Schopf, raises among others the question whether certain natural intermediates, which may be expected to occur in living tissue, react spontaneously to give the precursors of natural products. If so, then those same intermediates brought together in vitro, under biological conditions of temperature, dilution and pH, should react to form those same precursors. These, by further biochemical processes in the plant eg., by hydrogenation, decarboxylation, esterification, etc., are converted into the natural products.

For those that have a problem opening Pseudoephedrine use the ifile link

http://ifile.it/nxrm34z

java · « **Reply #152 on:** December 13, 2009, 03:50:57 PM »

Disproportionative Condensations. IV. The 3-Alkylation of Indoles by Primary and Secondary Alcohols
Ernest F. Pratt, Laurence W. Botimer
J. Am. Chem. Soc., 1957, 79 (19), pp 5248–5250

Abstract
A facile process for the 3-alkylation of indoles has been developed. A modification of the method which required heating
the indole with a large excess of an alcohol and alkoxide in a sealed tube, the new process is conduced in an open reflux
system with much smaller proportions of alcohol and alkoxide. Alkylated indoles have been prepared in good yield employing
a variety of primary and secondary alcohols. A reaction course closely analogous to that for several other base-catalyzed
alkylations by alcohols has been proposed and evaluated.

java · « **Reply #153 on:** December 13, 2009, 04:17:08 PM »

Preparation of certain 3-substituted indoles
Rita H. Cornforth and Sir Robert Robinson,
J. Chem. Soc., 1942, 680

java · « **Reply #154 on:** December 14, 2009, 12:30:10 AM »

Investigation of the synthesis of tropinone according to the Robinson-Schöpf reaction by a polarographic method
M. K. Polievktov, I. G. Markova, M. V. Lizgunova and O. Yu. Magidson
Pharmaceutical Chemistry Journal Vol 9(6) 1975, pp.413-417

{NB Translated from Khimiko-Farmatsevticheskii Zhurnal, Vol. 9, No. 6, pp. 55–60, June 1975}

Abstract
Tropine esters of a number of organic acids are widely used as drugs in world medical practice. Such preparations, approved for use in the USSR, include the natural alkaloid atropine and synthetic tropine esters: homatropine, tropaphen, and tropacine. Up to the present time, in the USSR tropine has been produced by hydrolysis of natural alkaloids. In view of the fact that the total demand for the preparations indicated above is far from satisfied by the plant materials that grow in the country, an urgent need has arisen for the development of an industrial method of production of tropine.

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Preparation of oxygen-18 enriched sulfur trioxide
K.K. Kelly and J.S. Matthews
The International Journal of Applied Radiation and Isotopes Volume 22(12) 1971, pp.729-730

Abstract
Oxygen-18 enriched sulfur trioxide has been prepared by a simple and relatively inexpensive procedure. This has been occomplished by the addition of sulfur trioxide to oxygen-18 enriched water to form fuming sulfuric acid containing approximately 50 per cent dissolved sulfur trioxide. On distillation of this fuming sulfuric acid, the sulfur trioxide obtained was enriched in oxygen-18. It was isolated and analyzed as its dimethylformamide complex.

java · « **Reply #155 on:** December 14, 2009, 11:59:01 AM »

Preparation and Reactions of Dialkoxytetrahydrofurans
Jorgen Fakstorp, Dolores Raleigh and L.E. Schneipp
J. Am. Chem. Soc. 1950, 72 (2), pp 869–874

Abstract
The opening of the furan rings by means of hydrolytic agents has long attracted considerable interest. However, only in the case of methylfuran and dimethylfuran has hydrolytic cleavage led to results of any practical importance. The investigations of Meinel and Clauson-Kaas and co-workers resulting in methods for the preparation of stable dialkoxydihydrofurans which are cyclic acetals of unsaturated 1,4-dicarbonyl compounds and easily converted into these, represent important advances in this field.

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The Ruff degradation: a review of previously proposed mechanisms with evidence that the reaction proceeds by a Hofer–Moest-type reaction
Jonathan A. Stapley, and James N. BeMiller
Carbohydrate ResearchVol.342(3-4) 2007, pp.407-418

Abstract
The Ruff degradation reaction is critically reviewed. Based on available information, the Hofer–Moest decarboxylation mechanism is presented as the mechanism for it. Cu(III) is proposed as the active species of the copper variant of the Ruff degradation, which is the most efficient form of the reaction.

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THE OXIDATION OF d-GLUCOSE BY MEANS OF COPPER IN SODIUM CARBONATE SOLUTION (SOLDAÏNI'S REAGENT)
Fred W. Jensen, Fred W. Upson
J. Am. Chem. Soc. 1925, 47 (12), pp 3019–3024

Abstract
The oxidation of the simple hexose and pentose sugars in alkaline solution by means of various oxidizing agents has been extensively studied by Nef and his students. In all of these experiments the oxidations were carried out in the presence of an excess of sodium hydroxide, usually six equivalents, in an initial concentration of approximately 5% sodium hydroxide. Nef and also Anderson have studied the oxidation of sugars by means of ordinary Fehling's solution.

java · « **Reply #156 on:** December 15, 2009, 10:47:32 AM »

Electro-oxidative decarboxylation of D-gluconic acid to D-arabinose on graphite electrodes
Giovanni Pezzatini, He Wei, Rolando Guidelli & Francesco Pergola
Electroanalysis Vol.4(1), pp.129-132

Abstract
A voltammetric investigation of the direct electro-oxidative decarboxylation of D-gluconate ion to D-arabinose on spectroscopic graphite electrode from methanol-water mixtures as well as from aqueous solutions is described. Practically a 100% yield in D-arabinose and and 80% yield in current were realized. The kinetic behavior points to a rate-determining release of the first transferring electron from the gluconate anion to the electrode, followed by a cleavage of the C-1-C-2 bond and by the resulting decarboxylation.

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Ergoline synthons: Synthesis of 3,4-dihydro-6-methoxybenz[cd]indol-5(1H)-one (6-methoxy-Uhle's ketone) and 3,4-dihydrobenz[cd]indol-5(1H)-one (Uhle's ketone) via a novel decarboxylation of indole-2-carboxylates
Michael D. Meyer, Lawrence I. Kruse
J. Org. Chem., 1984, 49 (17), pp 3195–3199

Abstract
An efficient synthesis of a new substituted ergoline synthon, 3,4-dihydro-6-methoxybenz[ed]indol-5(1H)-one, is described. This general synthetic strategy has also been applied to the preparation of the known 3,4-di-hydroxybenz[ed]indol-5(1H)-one, Uhle's ketone. The key step, a formal decarboxylation of intermediate 2-carboxy-3,4-dihydrobenz[ed]indol-5(1H)-one, is accomplished by reduction of the carboxylate ethyl ester to the indole-2-carboxaldehyde followed by catalytic decarbonylation to the parent indole using in situ generated Rh(1,3-bis(diphenylphosphino)propane)2+Cl- catalyst. The catalytic decarbonylation reaction was extended to several other indole-2-carboxyldehydes and appears to be a general reaction of indole alkaloids.

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Bufotenine esters.
Glennon RA, Gessner PK, Godse DD, Kline BJ
J. Med. Chem. 1979, 22 (11), pp 1414–1416

Abstract
Bufotenine (5-hydroxy-N,N-dimethyltryptamine) has been reported to be behaviorally inactive or only very weakly active in man and animals; this may be a consequence of its low partition coefficient and resultant inability to penetrate the blood--brain barrier. The acetyl, propionyl, butyryl, isobutyryl, and pivalyl esters of bufotenine were prepared for future pharmacological evaluation. Unexpectedly, it was found that these esters all possess a relatively high affinity for the serotonin receptors of the isolated rat stomach fundus preparation. A semiquantitative chromatographic measurement of ester hydrolysis suggests that extensive hydrolysis of the esters to bufotenine does not occur under the conditions of the affinity assay.

java · « **Reply #157 on:** December 15, 2009, 08:18:31 PM »

A Novel Synthesis of Substituted 1-Benzyloctahydroisoquinolines by Acid-Catalyzed Cyclization of N-[2-(Cyclohex-1-enyl)ethyl]-N-styrylformamides
Gerrit J. Meuzelaar, Ernst Neeleman, Leendert Maat and Roger A. Sheldon
European Journal of Organic Chemistry Volume 1998 Issue 10, Pages 2101-2108

Abstract
The acid-catalyzed cyclization of N-[2-(cyclohex-1-enyl)ethyl]-N-styrylformamides 1-5 gave access to 1-benzyl-2-formyloctahydroisoquinolines 6-10. The reactions were performed in the presence of the Lewis acid 9-borabicyclo[3.3.1]non-9-yl triflate. The cyclization of enamide 1 was also studied with Brønsted acid catalysts, such as triflic acid and the heterogeneous catalyst tungstophosphoric acid supported on silica gel. In all cases the 1,2,3,4,5,6,7,8-octahydroisoquinoline formed was accompanied by minor concentrations of one, two, or three isomeric octahydroisoquinolines. 1-Benzyl-2-formyloctahydroisoquinoline (6) could also be prepared from N-[2-(cyclohex-1-enyl)ethyl]formamide (11) by reaction with phenylacetaldehyde in a mixture of acetic acid and trifluoroacetic acid. The octahydroisoquinolines 6, 8, 10 as model compounds, were converted into the corresponding N-formylmorphinans.

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PYROLYSIS PRODUCTS OF POLYTETRAFLUOROETHYLENE AND POLYFLUOROETHYLENEPROPYLENE WITH REFERENCE TO INHALATION TOXICITY
HEIHACHIRO ARITO and REISUKE SODA
Ann. occup. Hyg.Vol. 20, No. 3, pp. 247-255, 1977

Abstract
Analysis of pyrolysis products of polytetrafluorocthylene (PTFE) and polyfluore ethylenepropylene (PFEP) and the influence of pyrolysis conditions on the pyrolysis products were investigated to evaluate the inhalation toxicity of those pyrolysis products. Both polymers were pyrolysed at various temperatures in a flow of nitrogen and air, either dry or humid. The pyrolysis products wcre analysed by infrared spectrometry and combined gas chromatographymass spectrometry. In pyrolysis of both polymers in a nitrogen stream, octofluoroisobutylene was identified in addition to the main products such as tetrafluoroethylene, hexafluoropropylene and octofluorocyclobutane. The main pyrolysis products of both polymers in an air stream were carbonyl fluoride and trifluoroacetyl fluoride. Tetrafluoroethylene and hexafluoropro pylene were far less in quantity but octofluoroisobutylene was found only with PFEP. Perfluoroalkanes were produced by oxidative pyrolysis of PTFE at high temperature. Effect of water vapour in the gas flow on the product formation was significant only in oxidative pyrolysis. In the presence of water vapour, carbonyl fluoride was converted into hydrogen fluoride and carbon dioxide, while trifluoroacetyl fluoride was converted to trifluoroacetic acid and hydrogen fluoride.

no1uno · « **Reply #158 on:** December 16, 2009, 12:40:57 AM »

Got this one - main product of pyrolysis of PTFE above 400'C is the monomer tetrafluoroethylene:

The Mechanism of the Depolymerization of Polytetrafluoroethylene with Pyrolitic and Radiolytic Initiation

Roland E. Florin, Midgett S. Parker and Leo A. Wall

J. Research. Nat. Buereau of Standards A: Physics & Chemistry
Vol.70A(2), 1966 pp.115-131

Abstract

The rate of decomposition of polytetrafluoroethylene, exposed to gamma radiation in a flowing helium atmosphere, was studied in the temperature 330'C to 450'C, dose rates 0.1 to 7.6 MR/h, and sample thicknesses 0.0006 to 0.01cm. Rate measurements were made with a thermal conductivity cell in the exit stream, which recorded essentially the difference between the thermal and radiation-induced rate, in total molecules of volatiles per second. At temperatures below about 400'C, the volatile products were a complex mixture. Above 400'C, tetrafluoroethylene was the major product, and the radiation-induced rate is proportional to the square root of dose rate, after appropriate allowance for the thermal initiation is made. Analysis of the results suggests that the rate of the thermal initiation has a very high preexponential factor, 10.29 to 10.29 n-1. The activation energy for termination is large, E>155kJ/mol. Diffusion and reverse reaction appear to be minor factors above 400'C, but a surface reaction may be important. The thermal decomposition mechanism seems clearly to consist of random initiation, termination by bimolecular recombination and a short kinetic chain (13 at 480'C).

java · « **Reply #159 on:** December 16, 2009, 11:40:47 AM »

1,3,4,5-Tetrahydrobenz[cd]indoles and related compounds. Part I. A new synthesis of 3,4-dihydrobenz[cd]indol-5(1H)-one (Uhle's ketone)
R. E. Bowman, T. G. Goodburn and A. A. Reynolds
J. Chem. Society Perkin Trans. 1 1972, 1121-1123

Abstract
New syntheses of 4-carboxyindole-3-propionic acid (9) starting from 3-amino-4-chlorobenzoic acid are described. A process involving thermal decarboxylation of 2,4-dicarboxyindole-3-propionic acid (

in aqueous alkali is shown to be suitable for the large-scale preparation of the diacid (9) and thence Uhle's ketone (1).

Author Topic: 2009 Reference and Translation Requests (Read 3039 times)

heisenberg

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heisenberg

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Quantum Dude

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heisenberg

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no1uno

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java

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no1uno

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java

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