Cyclooctatetraenoquinones. II. The synthesis and transformations of compounds related to dibenzo[a,e]cyclooctene-5,6,11(12H)-trione

1970 ◽  
Vol 48 (5) ◽  
pp. 796-804 ◽  
Author(s):  
Peter Yates ◽  
Errol G. Lewars
Keyword(s):  
Carbon Monoxide ◽  
Hydrogen Bromide ◽  
Selenium Dioxide ◽  
Ethyl Bromide ◽  
Bromo Derivative

Bromination of 11-acetoxydibenzo[a,e]cycloocten-5(6H)-one (6) gave the 6-bromo derivative (8), which on further bromination gave a hydrogen bromide adduct (12 or 13) of 6,6,12-tribromodibenzo[a,e]cyclooctene-5,11(6H,12H)-dione (14). Treatment of this adduct with aqueous-ethanolic ammonia followed by sublimation gave 11-oxoindeno[1,2-c]isocoumarin (4), not dibenzo[a,e]cyclooctene-5,6,11(12H)-trione (3) as earlier suggested. The conversion of 12 or 13 to 4 has been shown to involve the formation of 3-bromo-2-(o-carboethoxyphenyl)indone (17), which gave 4 and ethyl bromide on being heated at 180°. Oxidation of dibenzo[a,e]cyclooctene-5,11(6H,12H)-dione with selenium dioxide gave a bimolecular product 25 considered to be derived by loss of carbon monoxide from the dimer of dibenzo[b,ƒ]pentalene-5,10-dione (27), a selenium-containing product, 28, and the hydrate 29 of 3.

Catalysis by hydrogen halides in the gas phase. XVIII. Methyl formate and hydrogen bromide

1968 ◽  
Vol 21 (7) ◽  
pp. 1711
Author(s):  
DA Kairaitis ◽  
VR Stimson
Keyword(s):  
Carbon Monoxide ◽  
Gas Phase ◽  
Decomposition Product ◽  
Methyl Formate ◽  
Arrhenius Equation ◽  
Hydrogen Bromide ◽  
Radical Chain ◽  
Hydrogen Halides ◽  
Chain Decomposition ◽  
First Order

Hydrogen bromide catalyses the decomposition of methyl formate into carbon monoxide and methanol at 390-460�. The radical chain decomposition product, methane, is formed in only a small amount that is further reduced by the addition of inhibitor. The reaction is homogeneous and molecular, is first order in each reactant, and follows the Arrhenius equation: k2 = 1012.50exp(-32200/RT)sec-1 ml mole-1 It is not reversed by added methanol.

Thermal reactions of mesityl oxide

1971 ◽  
Vol 24 (5) ◽  
pp. 955 ◽  
Author(s):  
NJ Daly ◽  
MF Gilligan
Keyword(s):  
Carbon Monoxide ◽  
Methyl Bromide ◽  
Hydrogen Bromide ◽  
The Other ◽  
Mesityl Oxide ◽  
Thermal Reactions ◽  
First Order ◽  
First Order Kinetics

Mesityl oxide (4-methylpent-3-en-2-one) thermally decomposes in the range 412-490� give methylbutenes, carbon monoxide, isobutene, and methane as major products. The initial 20% of reaction follows first- order kinetics and is described by the equation k1 = 1014.22exp(-63240/RT) s-1. A Rice-Herzfeld chain is proposed. Addition of hydrogen bromide leads to two reactions, one producing isobutene, carbon monoxide, and methyl bromide, and the other leading to polymerization. Likely steps in the polymerization are proposed.

Catalysis by hydrogen halides in the gas phase. XIV. Methyl trimethylacetate and hydrogen bromide and the effects of added alcohols

1968 ◽  
Vol 21 (3) ◽  
pp. 687 ◽  
Author(s):  
JTD Cross ◽  
VR Stimson
Keyword(s):  
Carbon Monoxide ◽  
Methyl Ester ◽  
Gas Phase ◽  
Hydrogen Chloride ◽  
Hydrogen Bromide ◽  
Hydrogen Halides ◽  
Kinetic Form

Hydrogen bromide and hydrogen chloride catalyse the decomposition of methyl trimethylacetate into isobutene, carbon monoxide, and methanol at 370-442� and 450-48O�, respectively. The kinetic form, which is basically 1 : 1, is severely modified by the effect of methanol either produced in the reaction or added initially. Water or alcohols react with an intermediate in the catalysed decomposition of trimethylacetic acid or its methyl ester in esterification-like reactions; some of the resultant esters subsequently decompose to olefin and acid.

scholarly journals Microwave spectrum and molecular structure of the carbon monoxide-hydrogen bromide molecular complex

1980 ◽  
Vol 77 (10) ◽  
pp. 5583-5587 ◽  
Author(s):  
M. R. Keenan ◽  
T. K. Minton ◽  
A. C. Legon ◽  
T. J. Balle ◽  
W. H. Flygare
Keyword(s):  
Molecular Structure ◽  
Carbon Monoxide ◽  
Molecular Complex ◽  
Hydrogen Bromide ◽  
Microwave Spectrum

Annelation of organoboranes derived from geraniol

1976 ◽  
Vol 29 (3) ◽  
pp. 617 ◽  
Author(s):  
R Murphy ◽  
RH Prager
Keyword(s):  
Carbon Monoxide ◽  
Silver Nitrate ◽  
Electrophilic Reagent ◽  
Bromo Derivative

Alicyclic products have been obtained from geraniol derivatives in four ways: carbonylation of the intermediate borane either by treatment with carbon monoxide under pressure or by rearrangement of the cyanoborate under the influence of an electrophilic reagent; coupling under the influence of alkaline silver nitrate or by rearrangement of the bromo derivative obtained by photochemical bromination. The methods are compared and the nature of the products studied.

Isotopic Exchange Reactions of Gaseous Ethyl Bromide with Bromine, Hydrogen Bromide and Deuterium Bromide1

1950 ◽  
Vol 72 (1) ◽  
pp. 424-432 ◽  
Author(s):  
John B. Peri ◽  
Farrington Daniels
Keyword(s):  
Isotopic Exchange ◽  
Hydrogen Bromide ◽  
Ethyl Bromide ◽  
Exchange Reactions

ChemInform Abstract: Heterocyclization of Naphthylpropiolic Acids by Treatment with Hydrogen Bromide and Sulfur Dioxide or Selenium Dioxide.

ChemInform ◽  
2010 ◽  
Vol 24 (9) ◽  
pp. no-no
Author(s):  
YU. L. ZBOROVSKII ◽  
V. I. STANINETS ◽  
L. V. SAICHENKO
Keyword(s):  
Sulfur Dioxide ◽  
Hydrogen Bromide ◽  
Selenium Dioxide

The gas-phase decomposition of ethyl bromide

1971 ◽  
Vol 24 (10) ◽  
pp. 2031
Author(s):  
DA Kairaitis ◽  
VR Stimson
Keyword(s):  
Gas Phase ◽  
Initial Rate ◽  
Hydrogen Bromide ◽  
Bromine Atom ◽  
Ethyl Bromide ◽  
Phase Decomposition ◽  
Unimolecular Decomposition ◽  
Chain Reaction ◽  
Insight Into

The gas-phase decomposition of ethyl bromide at 423� in the presence of both ethylene and hydrogen bromide has been investigated. These additives, which are also the products, each influence the rate strongly but in opposite ways. The variation of initial rate with reactant pressure is given by (P in cm) ������������� k1 (min-1) = 15.2x10-3+19.5x10-3(PEtBrPHBr/PEne)1/2 This has been interpreted in terms of a unimolecular decomposition together with a bromine atom carried chain reaction with simple steps that involve the products. Some insight into the unaccompanied decomposition has been gained. Some remarks about the role of olefinic inhibitors in reactions producing hydrogen bromide have been made.

THE PHOTOLYSIS OF ACETONE IN THE PRESENCE OF HYDROGEN BROMIDE

1955 ◽  
Vol 33 (2) ◽  
pp. 383-390 ◽  
Author(s):  
M. J. Ridge ◽  
E. W. R. Steacie
Keyword(s):  
Carbon Monoxide ◽  
Hydrogen Bromide ◽  
Methyl Radicals ◽  
Methyl Radical

The presence of hydrogen bromide during the photolysis of acetone sharply inhibits the yields of carbon monoxide, ethane, and volatile methyl radical derivatives as measured by the function (CH4 + 2C2H6). The observed effects can be explained on the assumption that both acetyl and methyl radicals react rapidly with HBr.

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