- The thermal rearrangements of halocyclopropenes
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The gas phase thermal chemistry of several halocyclopropenes has been investigated. In each instance the cyclopropene was converted cleanly to an allene. The gas phase thermolysis of halocyclopropenes leads to allenes.
- Billups,Bachman, Robert E.
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- Process for producing propargyl bromide
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This invention provides a process of producing propargyl bromide in the absence of abase. The process comprises: A) bringing together in a reaction zone under an inert atmosphere and in the absence of a base and in the presence of an inert diluent, a feed of phosphorus tribromide and a separate feed of propargyl alcohol thereby forming a reaction mixture; B) while mechanically agitating the mixture being formed in A), maintaining the temperature of the mixture in the range of about 0° C. to about 25° C. to form a product mixture, and then C) raising the temperature of the product mixture to a temperature in the range of about 40° C. to about 60° C. while stirring the product mixture for a ride period of at least about 2.5 hours. Such process can be conducted as a batch process, as a semi-batch process, or as a continuous process.
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- SYNTHESIS OF BROMOALLENE UNDER CONDITIONS OF PHASE-TRANSFER CATALYSIS
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A new method was developed for the production of bromoallene by the dehydrobromination of 1,2,3-tribromopropane under the conditions of phase-transfer catalysis.It was shown that the bromoallene is produced as a result of the isomerization of the initially formed propargyl bromide.During the dehydrohalogenation of 2-bromo-3-chloro-1-propene, bromoallene, i.e.; the product from rearrangement with participation of the bromine atom, is formed in addition to propargyl chloride and chloroallene.
- Kurginyan, K. A.,Arakelova, S. V.,Kalaidzhyan, A. E.
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p. 2127 - 2130
(2007/10/02)
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- Carbon-Halogen Bonding Studies. Halogen Redistribution Reactions between Alkyl or Acetyl Halides and Tri-n-butyltin Halides
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The equilibrium positions have been determined for the halogen redistribution reactions of tri-n-butyltin halides with a variety of structurally different types of alkyl halides and with acetyl halides.These have been related through the reaction ΔGo values to carbon-halogen bond dissociation energy differences.It is suggested that the trends observed in the latter may provide evidence for the existence of a small steric bond weakening effect in the order C-I > C-Br > C-Cl bonds on going from methyl to primary, secondary, and tertiary alkyl halides.On the other hand, with the 2,3-? bond containing allyl, benzyl, and propargyl halides , α-haloacetones, and haloacetonitriles, there may be some type of electronic carbon-halogen bond strengthening effect which lies in order C-I > C-Br > C-Cl.Finally, for the acetyl halides, the data are in agreement with increases in bond strengths resulting from ? contributions being in the order C-Cl > C-Br > C-I.
- Friedrich, Edwin C.,Abma, Charles B.
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p. 1367 - 1371
(2007/10/02)
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