Methylene-dioxy-groups, formation

Interest is added to this mode of preparation by the observation of Hahn and Schales that not only j8-phenylethylamines containing a hydroxyl group in the nucleus, but also those with methoxyl or methylene-dioxy-groups, condense with phenylacetaldehydes or phenylpyruvic acids to tetrahydroisoquinolines, under conditions which could occur in a plant. The first stage in the condensation, viz., the formation of the iV-substituted aldehyde ammonia, e.g., R—CH,—CH2—NH—CH(OH)—R or the Schiff s base R—CE —CH — N=CHR takes place to greatest advantage at pH 5 and temperature 25° the second stage, intramolecular condensation to the tetrahydroisoquinoline, only occurs to the extent of 5 per cent. 

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