MALLIA, CARL,JAMES (2016) Using Modern Synthetic Techniques to Conduct Difficult Transformations Relating to the Agrochemical Industry. Doctoral thesis, Durham University.
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The work described in this dissertation is divided into three chapters each discussing independent projects where either gas-liquid flow technology or microwave reactor technology was applied to organic synthesis.
The first chapter describes the flow hydroxy-carbonylation of ortho-substituted iodo arenes. It was found that through the use of a “tube-in-tube” reactor to introduce the carbon monoxide gas to the reaction mixture, a number of ortho-substituted carboxylic acids could be prepared. The second part of this chapter deals with the synthesis of a herbicidal intermediate which was prepared through the carboxylation reaction with carbon dioxide (dry ice). A parallel flow process for the preparation of this herbicidal intermediate was also developed. This work was reported in one publication.
In the second chapter another gas; oxygen, was used in continuous flow as an oxidant in the Chan-Lam reaction. The first part of this chapter demonstrates how a continuous process for the synthesis of a herbicidal intermediate was developed through an optimised catalytic Chan-Lam reaction which was also shown to consistently work at different scales. In the second part a more generalised catalytic Chan-Lam reaction was optimised and this lead to a small collection of C-N coupled products. This work was published in one publication.
The use of 1,4-dithain-2,5-diol as a precursor for 2-mercaptoacetaldehyde was used as a building block for the synthesis of thiazoles in the third chapter. Using microwave reactor technology the optimised reaction conditions for this novel transformation was quickly achieved. A bifurcation pathway was discovered where either 2-aminothiophens or 2-substiuted thiazoles were prepared, which was demonstrated through the synthesis of a small library of compounds. This work was disclosed in two separate publications.
|Item Type:||Thesis (Doctoral)|
|Award:||Doctor of Philosophy|
|Keywords:||Flow chemistry, Gases in Flow, Carbon monoxide, Oxygen|
|Faculty and Department:||Faculty of Science > Chemistry, Department of|
|Copyright:||Copyright of this thesis is held by the author|
|Deposited On:||01 Sep 2016 11:05|