| 摘要 |
<p>The invention relates to a process for the preparation of 3-substituted thiophenes in which the substituent is a C4-C18-alkyl group. According to the invention, the preparation is carried out by allowing an alkali metal salt of a C4-C18-alkyl-succinic acid to react with a compound of sulfur and phosphorus, e.g. tetraphosphorus decasulfide, in an organic solvent at a temperature of 100-180 °C, the product obtained being 3-(C4-C18-alkyl)thiophene. The said reaction may be the last step in a process in which the initial material is maleic acid anhydride with which α-C4-C18-alkene is combined so that C4-C18-alkenylsuccinic acid anhydride is obtained, whereafter this is hydrogenated catalytically to produce C4-C18-alkylsuccinic acid anhydride. This is thereafter reacted with an alkali metal hydroxide so that an alkali salt of the C4-C18-alkylsuccinic acid is obtained, which salt is reacted with a compound of sulfur and phosphorus to produce 3-(C4-C18-alkyl)thiophene, which constitutes the final product.</p> |
