[CH3:1][O:2][C:3]([C:5]1[S:6][CH:7]=[CH:8][C:9]=1[S:10]([OH:13])(=O)=[O:11])=[O:4].S(Cl)([Cl:16])=O>>[CH3:1][O:2][C:3]([C:5]1[S:6][CH:7]=[CH:8][C:9]=1[S:10]([Cl:16])(=[O:13])=[O:11])=[O:4]7.4 G. of crude 3-sulfothiophene-2-carboxylic acid methyl ester are dissolved in 50 ml. of thionyl chloride and boiled to reflux for 16 hours. The mixture is then evaporated to dryness in vacuo and the remaining bright-yellow oil is brought to crystallization with petroleum ether. There is obtained 3-chlorosulfonylthiophene-2-carboxylic acid methyl ester.
Wird geladen…