β-Phenylethanol Amines. Part II. Studies on Cyclodehydration of a Few Acylamino Alcohols

Cyclodehydration of some acylamino alcohols to their corresponding isoquinolines has been studied. N-[β-hy-droxy-β(3, 4-methylenedioxyphenyl)ethyl]-cinnamamide and its dihydro derivative yield readily the corresponding isoquino­line derivatives, viz, 1-(styryl)-6, 7-methylenedioxy- and 1(β-phenyl)ethyl-6, 7-methylenedioxy-isoquinolines, whereas N-[β-hydroxy-β-(p-methoxyphenyl)ethyl] -cinnamamide and its dihydro derivative fail to cyclise when subjected to the Bischler-Napieralski reaction. During this reaction N-[β-hydroxy-β-(p-methoxyphenyl)ethyl]-cinnamamide suffers degradation to trans-cinnamamide and a dark brown styrene polymer