Synthesis and characterization of diaryl ditellurides and heterocyclic tellurium compounds /
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| Other Authors: | , , |
| Format: | Thesis Book |
| Language: | English |
| Published: |
1988.
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| Subjects: | |
| Online Access: | ProQuest, Abstract Link to OAKTrust copy |
| Abstract: | Previously unreported diaryl ditellurides were synthesized in yields ranging from 2 to 67% by three different methods. Diaryl ditellurides bearing functionalities compatible with Grignard reagents were obtained by treatment of arylmagnesium halides and air-oxidation of the intermediate tellurolates. Diaryl ditellurides carrying nitro, hydroxy, acetoxy, or amino substituents were prepared by reduction of the corresponding tellurinic acid derivatives. Bis(4-pyridyl) ditelluride and bis(3-chloro-2-pyridyl) ditelluride were synthesized by nucleophilic aromatic substitution, starting with the halopyridines and disodium ditelluride. 5-Selena-10-tellura-5,10-dihydroanthracene (phenoselenatellurine) was prepared in an overall yield of 4.2% starting with benzeneselenol. Condensation with 1,2-chloronitrobenzene produced 2-nitrophenyl phenyl selenide, which was converted to 2-chloromercurophenyl phenyl selenide. Transmetallation with tellurium tetrachloride followed by cyclization and reduction furnished phenoselenatellurine. A convenient route to 5,10-ditellura-5,10-dihydroanthracene (telluranthrene) was found to be the reaction of sodium telluride with 1,2-dichlorobenzene. Although the yields of telluranthrene were generally less than 5%, the method was suited for large-scale preparations. Similarly, 2,3-dibromonaphthalene and sodium telluride produced 7,14- ditellura-7,14-dihydropentacene. ditellura-7,14-dihydropentacene. A general three-step method was developed for the preparation of 2-methylareno[b]-3-aza-tellurophenes. 2-Acetamido-l-chloromercuriarenes and tellurium tetrachloride reacted with elimination of mercury(II) chloride to produce 2-acetamidoaryl tellurium trichlorides. The aryl tellurium trichlorides were reduced with aqueous sodium sulfide to the corresponding ditellurides. The ditellurides were isolated and then reduced with sodium borohydride to 2-acetamidoarenetellurols. Treatment of the resulting reaction mixtures with phosphorus trichloride produced 2-methylareno[b]-3-azatellurophenes. 2,6-Dimethylbenzo[d]-3-azatellurophene (22%), 2-methyl-6-tert-butylbenzo[d]- -3-azatellurophene (11%), 2-methyl-6-chlorobenzo[d]-3-azatellurophene (31%), and 2-methylnaphtho[2,l-d]-3-azatellurophene (13%) were prepared in this manner from 4- methylaniline, 4-tert-butylaniline, and 2-aminonaphthalene, respectively, in overall yields given in parentheses... |
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| Item Description: | Typescript (photocopy). Vita. "Major subject: Chemistry." |
| Physical Description: | xi, 109 leaves : illustrations ; 29 cm |
| Bibliography: | Includes bibliographical references. |