Studies on Tetrahydroisoquinolines. III. Synthesis of 4-Alkoxy- or Alkyl (phenyl)-mercapto-7-hydroxy-6-methoxy-2-methyl-1, 2, 3, 4-tetrahydroisoquinolines

Abstract

Treatment of 4, 7-diacetate (I) with alcohols or alkyl (phenyl) mercaptans in the presence of base gave the corresponding 4-alkoxy or alkyl (phenyl) mercapto derivatives (VIak) in moderate yields. In the case of alcohols, the steric effect of alkyl chains was found to be governing as expected. Nuclear magnetic resonance spectra of the products were measured and magnetic nonequivalence of isopropoxyl methyl protons due to hindered rotation was observed in the case of 4-isopropoxy compound (VIf).