An investigation of reactions directed towards the synthesis of 2-methyl-2-(methylthio)propanal oxime

Whittaker, Ruth Eleanor (1995) An investigation of reactions directed towards the synthesis of 2-methyl-2-(methylthio)propanal oxime. Masters thesis, Rhodes University.

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Abstract

The processes leading to the formation of 2-methyl-2-(methylthio)propanal oxime, known industrially as aldicarb oxime, have been studied. The three stages of the synthesis, viz., chlorination, thiomethylation and oximation have been thoroughly investigated, with the aim of optimising the yield and purity of aldicarb oxime. Attention has been focused on the chlorination step, and the effects of altering various conditions have been determined; the reaction has been carried out in the absence and presence of heat, solvent and buffer, and the extent of chlorine addition has also been varied. These studies have led to some improvement in the yield for this step. Several simple and inexpensive methods for purifying contaminated batches of aldicarb oxime have also been examined. Possible aldicarb oxime contaminants, identified by GLC and GC-MS analysis, have been synthesised for use as chromatographic and spectroscopic standards, and confirmation of the presence of a number of these contaminants has been achieved. Aldehyde trimers have been found to be the primary contaminants present in aldicarb oxime and the thermal stability of these trimers, their corresponding monomers and aldicarb oxime itself has been studied using variable temperature ¹H NMR spectroscopy. Novel pyridine derivatives, with potential as aldicarb analogues, have been synthesised and characterised using spectroscopic methods.

Item Type:Thesis (Masters)
Uncontrolled Keywords:Pesticides, Insecticides, Aldicarb
Subjects:Q Science > QD Chemistry
Divisions:Faculty > Faculty of Science > Chemistry
Supervisors:Kaye, P.T.
ID Code:3615
Deposited By: Ms Chantel Clack
Deposited On:10 Oct 2012 12:14
Last Modified:10 Oct 2012 12:14
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