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Title: The synthesis of aryl ethers
Author: Jones, D.
Awarding Body: University College of Swansea
Current Institution: Swansea University
Date of Award: 1994
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The synthesis of biaryl ethers is a process of importance in many fields within the chemical industry. Generally, the Ullmann ether synthesis is employed, though improvements in the general method have not been commonplace since the inception of the process at the turn of the century. By reinvestigating the parameters present, it was found that the use of cuprous iodide in a solventless reaction led to high yields of diaryl ethers. Further improvements were developed by the implementation of ultrasound in conjunction with lower reaction temperatures, with similarly high yields being afforded. Study was then undertaken to investigate the applicability of electrophilic bromination of various aromatic moieties. Thus, phenol, 2-methoxyphenol and aniline were examined in relation to the amount of ortho-bromination occurring with reagents such as 1,3-dibromo-5,5-dimethylhydantoin and N-bromosuccinimide in the presence of solid supports. These studies indicated that the use of solid supports, especially Amberlyst 15 and XN1010 and Montmorillonite K10 realised high degrees of bromination, though in the case of aniline the natural tendency to realise bromination in the para-position reduced the observed effectiveness of the process. By the implementation of acetyl hypobromite and N,N-dibromourethane, good para selectivity was found for the bromination of toluene in the presence of solid supports, though when applied to nitrobenzene, bromination of the straight chain alkane present at the internal standard present for gas chromatography analysis occurred. The use of molecular bromine in conjunction with solid supports such as Montmorillonite K10 led to high yields of 1-bromonaphthalene.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available