专利号:US-5856500-A 优先权日:1997-03-11 标题:Synthesis of thiazole derivatives 发明人:MATTHEWS MICHAEL D; MALCOLM ARCELIO J 权利人:ALBEMARLE CORP 摘要:N- 4-(Cyanoethylthiomethyl)-2-thiazolyl!guanidine, is prepared by (a) mixing 1,3-dihaloacetone and 2-imino-4-thiobiuret in a suitable polar organic solvent at initial temperatures of about -10° to about 25° C., and agitating the mixture at about -10° to about 60° C. for at least about 1 hour; (b) heating the resultant mixture at about 40° to about 60° C. for at least about 0.5 hour; (c) mixing with the mixture from (b), thiourea and then water at about 40° to about 60° C. for a period of at least about 1 hour; (d) removing liquid polar solvent from the mixture of (c); and (e) mixing with the mixture from (d), 3-halopropionitrile and water-soluble alcohol, ether, or ether-alcohol, followed by aqueous alkali metal hydroxide while maintaining the temperature at below about 20° C., to form N- 4-(cyanoethylthiomethyl)-2-thiazolyl!guanidine. The process avoids isolating and purifying any of the intermediates, and can be conducted in the same vessel, as a 'one-pot' synthesis.
专利号:WO-9840367-A1 优先权日:1997-03-11 标题:Novel thiazole derivatives and their preparation 发明人:RAMACHANDRAN VENKATARAMAN; MALCOLM ARCELIO J 权利人:ALBEMARLE CORP 摘要:1-(4-Bromomethyl-2-thiazolyl)guanidine, and its acid addition salts, especially 1-(4-bromomethyl-2-thiazolyl)guanidine hydrobromide are novel compounds useful as starting materials for the synthesis of famotidine. These compounds can be produced without need for prolonged reaction periods at extremely low temperatures by mixing 1,3-dibromoacetone and 2-imino-4-thiobiuret in a suitable reaction medium. Moreover, the novel compounds can be selectively synthesized in good yield and purity from a raw material containing a combination of structurally similar analogs of 1,3-dibromoacetone.
专利号:WO-9840368-A1 优先权日:1997-03-11 标题 :Synthesis of thiazole derivatives
专利号:WO-9840369-A1 优先权日:1997-03-11 标题 :Synthesis of thiazole derivatives