Thiophen derivatives

Novel 2,3-disubstituted thiophen derivatives (and acid addition salts thereof) having anthelmintic properties and of the general formula wherein X represents -CH2-CH2-, CH2-CH2- or -CH=CH-, Y represents -CH2-CH2 or -CH2-CH2-CH2- and R represents -H or -CH3, are prepared (1) by the interaction of an acid addition salt of an imidate ester of the formula (n is 2 or 3 and R2 is an alkyl radical containing 1 to 6 carbons) and an alkylene diamine H2N-Y-NHR (Y and R as defined above), or (2) by the interaction of 2-formyl-3-methylthiophen and either 2-methyl-D 2-imidazoline or 2-methyl - D 2 - tetrahydropyrimidine (thus producing compounds in which X is -CH=CH-), or (3) by the methods specified in Specification 1,045,838. Veterinary compositions having anthelmintic properties contain as the active ingredient the above novel compounds and the compositions are administered orally via drinking water, as throat drench solutions, in admixture with feed or mineral supplements such as salt, or in the form of dosage units such as tablets, boluses and capsules. 3 - (3 - Methyl - 2 - thienyl)acrylonitrile is prepared by reacting 2-formyl-3-methylthiophen with cyanoacetic acid in the presence of ammonium acetate. Reduction of this nitrile affords 3 - (3 - methyl - 2 - thienyl) - propionitrile from which methyl b - (3 - methyl - 2 - thienyl) - propionimidate hydrochloride is obtained by reaction with methanol and hydrogen chloride.