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Title:	Synthesis of aroylthiourea derivatives for the metathesis of methyl oleate by ruthenium catalysts
Authors:	Nor Wahida Awang (P72598)
Supervisor:	Bohari M. Yamin, Prof. Dr.
Keywords:	Synthesis Aroylthiourea Metathesis Methyl oleate Ruthenium Universiti Kebangsaan Malaysia -- Dissertations
Issue Date:	8-Oct-2017
Description:	This project consists of two parts. In the first part 13 new monoaroylthiourea derivatives of secondary amine, 2-(ethylamino)ethanol were synthesized and characterized by infrared (IR), ultraviolet visible (UV-Vis), mass spectrometer (MS), gas chromatography (GC-MS) and nuclear magnetic resonance (NMR) spectroscopic techniques. The thioureas are N-(2-fluorobenzoyl)-N-(2-(ethylamino)ethan-1-ol) thiourea (1a), N-(3-fluorobenzoyl)-N-(2-(ethylamino)ethan-1-ol) thiourea (1b), N-(4-fluorobenzoyl)-N-(2-(ethylamino)ethan-1-ol) thiourea (1c), N-(2-bromobenzoyl)-N-(2-(ethylamino)ethan-1-ol) thiourea (2a), N-(3-bromobenzoyl)-N-(2-(ethylamino)ethan-1-ol) thiourea (2b), 2-(1-ethylthioureido)ethyl 4-bromobenzoate (2c), N-(3-iodobenzoyl)-N-(2-(ethylamino)ethan-1-ol) thiourea (3a), 2-(1-ethylthioureido)ethyl 4-iodobenzoate (3b), N-(3-methoxybenzoyl)-N-(2-(ethylamino)ethan-1-ol) thiourea (4a), N-(4-methoxybenzoyl)-N-(2-(ethylamino)ethan-1-ol) thiourea (4b), N-(2-nitrobenzoyl)-N-(2-(ethylamino)ethan-1-ol) thiourea (5a), N-(3-nitrobenzoyl)-N-(2-(ethylamino)ethan-1-ol) thiourea (5b) and N-(4-nitrobenzoyl)-N-(2-(ethylamino)ethan-1-ol) thiourea (5c). The yield of the products were quite high in the range of 54.1-88.5% and the melting points of the compounds lies in the range of 110.0-155.4 ºC except for 2c and 5c. All the protons in the compounds were detected except the amino and hydroxyl protons for certain compounds; plausibly due to the deuterium exchange with the solvent. The NMR spectrum showed the presence of side product and supported by GC-MS analysis. X-ray structure of all the compounds except for 3a and 5b showed all of them adopt cis configuration with respect to the position of the carbonyl and thiono groups about their C-N bonds with some degree of twisting. Antibacterial studies against 3 human pathogenic bacteria microorganisms belonging to both gram-positive and gram-negative groups; Escherichia coli (ATCC 8739), Bacillus cereus (ATCC 10876) and Vibrio Parahaemolyticus (ATCC 17802) using disc diffusion techniques showed that the thiourea containing halogen substituted group such as fluoro, bromo and iodo possess activity at high concentration of 10 mg/mL. The second part is an olefin metathesis reaction of methyl oleate as model compounds for plant based methyl ester. There were two types of metathesis that have been explored namely self-metathesis (SM) and cross metathesis (CM) of methyl oleate (A). In self metathesis, a few parameters include reaction time, solvent effect, catalyst loading and temperature were investigated. The optimisation of parameters have been found to be at 50 ºC, 1 hour reaction time in dichloromethane. The products namely (E)-octadec-9-ene (SM1) and (E)-dimethyl octadec-9-enedioate (SM3) were produced. Meanwhile in cross metathesis, other parameters (e.g catalyst, molar substrate ratio) have been investigated. The reaction condition for cross metathesis were optimised at 1 hour reaction time under high molar ratio, 10 equivalent of substrate using Grubbs 2nd generation catalyst, RuCl2(PCy3)(IMesH2)(CHPh) [IMesH2 = 1,3-bis(2,4,6-trimethylphenyl) imidazolin-2-ylidene; Cy=cyclohexyl] (G2) in dichloromethane. In the cross metathesis with both terminal and internal olefins, the targeted products were accompanied by side products from self-metathesis of MO. The side products could be reduced by increasing the molar substrate ratio to improve conversion and selectivity. The Hoveyda-Grubbs 2nd generation catalyst showed a better activity than the Grubbs 2nd generation in cross metathesis with highly functionalized substrate. However, the Grubbs 1st generation showed no activity thus it is not an efficient catalyst. Cross metathesis reactions of methyl oleate with cis-4-octene (B), cis-stilbene (D) using G2 afforded CM products with high MO conversion and high selectivity under high molar (B/MO, D/MO) ratios while CM with cis-1,4-diacetoxy-2-butene (C) afforded metathesis products with low MO conversion under the same reaction conditions. The efficient CM with allyltrimethylsilane proceeded with high activity, whereas the CM with vanillylidenacetone, β-pinene, allyl glycidyl ether and allyl phenyl carbonate proceeded with low MO conversion. Cross metathesis with internal olefin gave high conversion and yields compared to terminal olefin.,Certification of Master's/Doctoral Thesis" is not available
Pages:	270
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Science and Technology / Fakulti Sains dan Teknologi

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