[Synthesis, stereochemistry and anticonvulsant action of 4-phenyltetrahydroisoquinolines].

The racemic and optically active 4'- and 8-substituted tetrahydroisoquinolines 2-5 have been synthesized and their effect on the water-immersion stress ulcer in rats has been studied. All compounds prevent the formation of stress ulcer, the strongest effect being exhibited by compound 4 and its dextrarotatory isomer (R1 = Cl, R2 = NHCOOC2H5). The antiulcer activity of 4 is 30 to 50 times higher than that of the H2 receptor antagonists Cimetidin and Ranitidin used for comparison. The absolute configuration of the optically active compounds 2, 3 and 4 has been determined by means of chemical correlation. The antiulcer activity of 4 is characterized by enantioselectivity, S-(+)-4 is three times as active than R-(-)-4.