DE1745778

Novel 2-ethyl thiophene derivatives having the general formula wherein R is hydrogen or a methyl group and n is 2 or 3 and the non-toxic acid addition salts thereof, are prepared by reacting a Grignard reagent of 2-(21-halogenoethyl) thiophene with a halogeno carboxylic acid nitrile Halogen-(CH2)n-CHR-CN, where n and R have the meaning above. 2 - Methyl - 4 - (tetrahydro - 2 - pyranyloxy) butyronitrile is prepared by reaction of the sodium derivative of propionitrile with 2-(tetrahydro-2-pyranyloxy) ethyl chloride. 2 - Methyl - 4 - hydroxy - butyronitrile is prepared by refluxing the tetrahydro-2-pyranyloxy derivative with concentrated hydrochloric acid. 2 - Methyl - 4 - chloro - butyronitrile is prepared by reaction of the corresponding 4-hydroxy compound with thionyl chloride. Veterinary compositions having anthelmintic properties and which can be administered orally or parenterally in the form of solutions or as an additive to animal feedstuffs, contain a compound of the general formula above as the active ingredient. 2-(21-Ethyl) thiophene magnesium halides are prepared by reacting 2-(21-halo-ethyl) thiophene with magnesium in ether.