Bottini, Albert Thomas (1957) I. Mechanisms for liquid phase hydrolyses of chlorobenzene and halotoluenes. II. The products from the reaction of N-(2-bromoallyl)-ethylamine with sodium amide. III. The nitrogen inversion frequency in cyclic imines. IV. The nuclear magnetic resonance spectrum of Feist's acid. Dissertation (Ph.D.), California Institute of Technology. http://resolver.caltech.edu/CaltechETD:etd-07082004-142125
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Part I. A study of the rearrangements which occur during the high temperature liquid phase hydrolyses of the halotoluenes has shown that the extent of rearrangement is a sensitive of temperature, base strength and the nature of the halogen. These hydrolyses involve either a benzyne (elimination-addition) mechanism, which gives both rearranged and unrearranged products, or an [...]-type mechanism. The [...]-type mechanism was found to be favored at lower temperatures, in the presence of weaker bases and with the more easily ionizable halogens. By suitable choice of conditions, one or the other reaction could be made to occur almost exclusively. Chlorobenzene-[...],with 4 M sodium hydroxide solution at 340[degrees], gave 58[plus or minus]1% [...] and [...], which indicates that under these conditions the benzyne mechanism predominates but is not the exclusive reaction path.
Part II. The principal product obtained from N-(2-bromoallyl)-ethylamine and sodium amide in liquid ammonia has been shown to be N-ethylallenimine as proposed by Ettlinger and Kennedy rather than N-ethylallylideneamine. N-Ethylpropargylamine was also isolated in small yield from this reaction. N-Ethylpropargylamine was obtained in 71% yield by treatment of N-(2-chloroallyl)-ethylamine with potassium amide in liquid ammonia.
Part III. The nuclear magnetic resonance spectra of derivatives of cyclic imines ranging in ring size from three to six were examined. The temperature dependent spectra of aziridine (ethylenimine) derivatives allowed an evaluation of the factors which affect the nitrogen inversion frequency. Conjugation with nitrogen and, generally to a lesser degree, bulkiness of the group attached to nitrogen increase the inversion frequency. Two groups attached to carbon on opposite sides of the imine ring also increase the inversion frequency. One, or two subtituents attached to the ring carbons in a cis manner essentially fix the configuration about nitrogen with the N-substituent trans to the other group (s). The inversion frequency is decreased in hydroxylic solvents due to stabilization of configuration by hydrogen bonding with nitrogen. The data obtained indicate that theoretically resolvable aziridines in which the asymmetric center is trivalent nitrogen are resolvable only at temperatures below -50[degrees]. The nitrogen inversion frequency in N-substituted azetidines (trimethylenimines) and larger-ring imines is too great to measure from nuclear magnetic resonance data at temperatures above -77[...].
Part IV. The nuclear magnetic resonance spectrum of Feist's acid, as the sodium salt in a basic solution of deuterium oxide, was found to be consistent with the structure 3-methylene-1,2-trans-cyclopropanecarboxylic acid (I). It was discovered that the ring hydrogens undergo exchange with the solvent whereas the methylene hydrogens do not appear to exchange. These facts cast serious doubt on the possibility of a facile equilibration of I and 3-methyl-1,2-cyclopropenedicarboxylic acid (II). Structure II has been considered elsewhere to account for the ozonization product of esters of I. A mechanism that accounts for the formation of ethyl acetoxaloacetate in the ozonization of the diethylester of I has been developed.
The nuclear magnetic resonance spectrum of the reduction product of I was also studied. The ring hydrogens did not appear to undergo exchange with the solvent in a deuterium oxide solution of sodium deuteroxide.
|Item Type:||Thesis (Dissertation (Ph.D.))|
|Degree Grantor:||California Institute of Technology|
|Division:||Chemistry and Chemical Engineering|
|Thesis Availability:||Public (worldwide access)|
|Defense Date:||1 January 1957|
|Default Usage Policy:||No commercial reproduction, distribution, display or performance rights in this work are provided.|
|Deposited By:||Imported from ETD-db|
|Deposited On:||13 Jul 2004|
|Last Modified:||26 Dec 2012 02:54|
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