Different Thiophene Oxazoline Ketone Derivatives

The synthesis of the derivatives of 3-isothiazolones is carried out in this thesis. The 3-isothiazolones are synthesized from methyl acrylate. Thin-Layer Chromatography (TLC), Wet-Column Chromatography (WCC) are used to isolate, and the structure of the derivatives of 3-isothiazolones are affirmed by IR spectroscopy, 'H NMR, and 13C NMR.A series of derivatives of 3-isothiazolones4, 5-dichloro-2-n-octyl-4-isothiazolin-3-one;4, 5-dichloro-2-(3-methoxypropyl)isothiazol-3-one;4, 5-dichloro-2-(3-ethoxypropyl)isothiazol-3-one;4, 5-dichloro-2-(3-isopropoxypropyl)isothiazol-3-one;4, 5-dichloro-2-(3-butoxypropyl)isothiazol-3-one;4, 5-dichloro-2-(3-methoxyethoxypropyl)isothiazol-3-one;4, 5-dichloro-2-(chloromethyl)isothiazol-3-one;and the mixture of 5-chloro-2-(3-methoxypropyl)isothiazol-3-one2-(3-methoxypropyl)isothiazol-3(2H)-one have been successfullysynthesized through Michael addition. amidation reaction, cyclizationreaction steps. The suitable synthesis conditions of these new productshave been studied respectively . The influences of different substitutionsand the length of hydrophobic group on the solubility, polarity, biocidalproperties of these new products have also been investigated in detail.The results indicated as following:1. Although the reactants used in the amidation reaction of the disulfideester have similar structure, the reaction conditions are various.Gererally, triethylamine is used as catalyzer, the synthesis wouldtake longer time under lower temperature. 2, The cyclization is performed by reacting the disulfide-amide with ahalogenating agent. Sulfuryl chloride is used in this reaction as thehalogenating agent. By providing an excess of halogenating agent, theisothiazolone may be halogenated at the 4- or 5-positions. The productof di-halogenation will be obtained only when 6 mole equivalents ofhalogenating agent are available. 3. The solubility, polarity of the products will become strongerrespectively with the increasing of the number of aether and the lengthof hydrophobic group. 4. The products we got showed a broad spectrum of biocidal properties andare particularly effective for the control of microorganism.