2-Substituted 4-anilinopiperidines from 2H-thiopyran-2-thiones

4-Dimethylamino-5,6-dihydro-2 H -thiopyran-2-thiones were converted to 4-anilinodihydropyridine-2(1 H )-thiones in several steps. The latter were alkylated giving a mixture of isomeric methylthioderivatives which were hydrogenated with Raney nickel yielding 2-alkyl- and 2-aryl-substituted 4-anilinopiperidines. The configurations as well as the conformations of the formed diastereoisomers are investigated by means of NMR.