CAS: 84522-35-0; 3-[(2,2-Dimethoxyethyl)Thio]Propene

专利信息

专利号:US-4471139-A
优先权日:1982-05-24
标题 :Processes for making 3-methylthiophene-2-carboxaldehyde and intermediates therefor
发明人：ANDREWS GLENN C
权利人:PFIZER
摘要:Processes for preparing isomerically pure 3-methylthiophene-2-carboxaldehyde, an intermediate for synthesis of anthelmintic agents, by reaction of mercaptoacetaldehyde or the dimer, or a polymer thereof, or a dialkylacetal thereof in the presence of a base with (1) methyl vinyl ketone or an alpha- or beta-oxidized derivative of methyl vinyl ketone to form a 3-oxobutylmercaptoacetaldehyde or dialkyl acetal thereof, or an alpha- or beta-substituted derivative thereof which is then converted to 3-methylthiophene-2-carboxaldehyde via appropriate steps including, if necessary, treatment with acid, followed, if necessary, by enamine catalyzed cyclization and, in the case of using methyl vinyl ketone as reactant, a dehydrogenation step; or (2) 3-butyn-2-one to produce a mixture of isomeric 3-oxobut-1-enylmercaptoacetaldehyde or dialkyl acetals thereof which is cyclized to 3-methylthiophene-2-carboxaldehyde. n A further aspect of this invention is an improved process for making dialkyl acetals of 2-mercaptoacetaldehyde which comprises reacting an alkyl vinyl ether with sulfur chloride to produce a bis(2-chloro-2-alkoxy ethyl)disulfide which is then treated with an alcohol to afford a bis(2,2-dialkoxyethyl)disulfide which is reduced under alkaline conditions to 2-mercaptoethyl acetaldehyde alkali metal salt which can be alkylated to a thioether, a valuable intermediate.

专利号:US-4476312-A
优先权日:1982-05-24
标 题:Processes for making 3-methylthiophene-2-carboxaldehyde and intermediates therefor
发明人：ANDREWS GLENN C
权利人:PFIZER
摘要:Processes for preparing isometrically pure 3-methylthiophene-2-carboxaldehyde, an intermediate for synthesis of anthelmintic agents, by reaction of mercaptoacetaldehyde or the dimer, or a polymer thereof, or a dialkylacetal thereof in the presence of a base with (1) methyl vinyl ketone or an alpha- or beta- oxidized derivative of methyl vinyl ketone to form a 3-oxobutylmercaptoacetaldehyde or dialkyl acetal thereof, or an alpha- or beta-substituted derivative thereof which is then converted to 3-methylthiophene-2-carboxaldehyde via appropriate steps including, if necessary, treatment with acid, followed, if necessary, by enamine catalyzed cyclization and, in the case of using methyl vinyl ketone as reactant, a dehydrogenation step; or (2) 3-butyn-2-one to produce a mixture of isomeric 3-oxobut-1-enylmercaptoacetaldehyde or dialkyl acetals thereof which is cyclized to 3-methylthiophene-2-carboxaldehyde. n A further aspect of this invention is an improved process for making dialkyl acetals of 2-mercaptoacetaldehyde which comprises reacting an alkyl vinyl ether with sulfur chloride to produce a bis(2-chloro-2-alkoxy ethyl)disulfide which is then treated with an alcohol to afford a bis(2,2-dialkoxyethyl)disulfide which is reduced under alkaline conditions to 2-mercaptoethyl acetaldehyde alkali metal salt which can be alkylated to a thioether, a valuable intermediate.