Studies on the syntheses of heterocyclic compounds. Part CDI. Rearrangement of β-hydroxylaudanosine

Abstract

1,2,3,4-Tetrahydro-1-(α-hydroxy-3,4-dimethoxybenzyl)-6,7-dimethoxy-2-methylisoquinoline (β-hydroxylaudanosine)(5) was treated with toluene-p-sulphonyl chloride in the presence of triethylamine to afford 2,3-dihydro-7,8-dimethoxy-5-(3,4-dimethoxyphenyl)-3-methyl-1H-3-benzazepine (6), whose reduction product (9) was also obtained by dehydrative cyclisation of β-hydroxy-3,4-dimethoxy-N-(3,4-dimethoxyphenethyl)phenethylamine (15), followed by an Eschweiler–Clarke reaction of the resulting benzazepine (18).