Verfahren zur Herstellung von 2-Alkylthiophenverbindungen

摘要

The invention comprises compounds of the formula where X represents -CH2-CH2-, -CH2-CH2-CH2- or -CH = CH-, Y represents -CH2-CH2- or -CH2-CH2-CH2-and R represents -H or -CH3, the non-toxic acid addition salts thereof, and methods for preparing these compounds. When X represents -CH2-CH2-or-CH2-CH2-CH2-the thiophen derivatives are prepared by reacting an alkylene diamine, H2N-Y-NH.R, where Y and R are as defined above with either the hydrochloride or an imidate ester of formula where n is 2 or 3 and R2 represents an alkyl radical with 1 to 6 carbon atoms or a nitrile of formula where n is 2 or 3, in the presence of an organic sulphonic acid or gaseous hydrogen sulphide. When X represents -CH = CH-, an alkylene diamine is reacted with the hydrochloride of 3 - (11 - imino - 31 - (211 - thienyl)allyloxy) -propane sulphonic acid and, when required, isolating the desired free base from the resulting hydrochloride salt which latter compound is prepared by reacting 2-thienyl-acrylamide with 1,3-propane sultone. 3-(21-thienyl)propionitrile is prepared by hydrogenating 3-(21-thienyl)-acrylonitrile which is made by refluxing 2-thiophene - carboxaldehyde with cyanoacetic acid. Pharmaceutical compositions having anthelmintic activity contain as the active ingredient compounds of the first general formula where X, Y and R are as defined above and non-toxic acid addition salts thereof. The compositions may be administered as solutions, in admixture with feed or mineral supplements or in the form of tablets, boluses or capsules.ALSO:The invention comprises an adsorbate of compounds of general formula where X represents -CH2-CH2-, -CH2-CH2-CH2- or -CH = CH-, Y represents -CH2-CH2- or -CH2-CH2-CH2- and R represents -H or -CH3 and a cation-exchange resin such as the sodium form of a styrene/divinyl benzene copolymer having sulphonate cation-exchange groups.