PART I. A NEW SYNTHESIS OF OLEFINS. PART II. SUBSTITUTION AT TERTIARY CARBON: INHIBITION AND RETARDATION BY DI-TERT-BUTYL NITROXIDE. PART III. REDUCTION OF NITROXYL RADICALS TO SECONDARY AMINES. PART IV. (A) SUBSTITUTION AT TERTIARY CARBON. PRELIMINARY STUDY OF AMINES AS NUCLEOPHILES. (B) PRELIMINARY STUDY OF THE REACTIONS OF N-(PARA-NITROCUMYL)-QUINUCLIDINIUM CHLORIDE WITH ANIONS. (C) PREPARATION OF ETHYL HYPOPHOSPHITE AND PRELIMINARY STUDY OF IT

HAROLD WILLIAM PINNICK, Purdue University

Abstract

Part I. Vicinal dinitro compounds are transformed into tetra-substituted olefins by the agency of sodium sulfide nonahydrate or sodium thiophenoxide. These reactions take place readily at room temperature and give excellent yields of pure products. Olefin formation is inhibited, or retarded, by free radical scavengers--e.g. di-t-butyl nitroxide. Catalytic amounts of electron acceptors, e.g. m-dinitrobenzene, have profound effects on these reactions. Light speeds up the elimination process and, indeed, is essential when sodium thiophenoxide is employed. These facts strongly support a radical anion-free radical chain mechanism. Part II. Di-t-butyl nitroxide inhibits (or retards) the reactions of p-nitrocumyl chloride and (alpha), p-dinitrocumene with nucleophiles. This provides support for the view that the mechanism of these reactions involves a free radical chain sequence. In contrast, reactions of m-nitrocumyl chloride and (alpha), m-dinitrocumene with nucleophiles are largely unaffected by di-t-butyl nitroxide. Consequently, it is clear that reactions in the meta-nitrocumyl system proceed by a significantly different mechanism than that proposed for the para system. Part III. Di-t-butyl nitroxide, 2,2,6,6-tetramethylpiperidine-1-oxyl and 2,2,6,6-tetramethyl-4-piperidinol-1-oxyl are each reduced to the corresponding amine in 50 to 80% yields on treatment with sodium sulfide nonahydrate in DMF. These reactions are accelerated by sulfur. Part IVa. The observation of Stuchal('1) that amines react with p-nitrocumyl chloride and (alpha), p-dinitrocumene has been substantiated. In addition, it has been found that tertiary amines do not undergo alkylation by (alpha), p-dinitrocumene. Part IVb. N-(p-Nitrocumyl)-quinuclidinium chloride reacts with sodium nitrite and sodium azide to give good yields of (alpha), p-dinitrocumene and p-nitrocumyl azide, respectively. Treatment of the quaternary salt with sodium phenoxide gives a mixture of p-nitrocumylphenyl ether and p-nitro-(alpha)-methylstyrene. Part IVc. Pure ethyl hypophosphite is obtained in 70 to 80% yields on reacting sodium hypophosphite with triethyloxonium fluoroborate in methylene chloride. Ethyl hypophosphite reduces sodium benzenesulfinate to diphenyl disulfide. Part IVd. Vicinal dinitro compounds with no hydrogens on the carbons bearing the nitro groups react with sodium methoxide to give products derived from loss of nitrous acid. Two moles of nitrous acid can be eliminated upon prolonged treatment of the dinitro compound with base. . . . (Author's abstract exceeds stipulated maximum length. Discontinued here with permission of author.) UMI ('1)F. W. Stuchal, Ph.D. Thesis, Purdue University, 1970.

Degree

Ph.D.

Subject Area

Organic chemistry

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