3.5- Dimethoxy-5-hydroxyphenethylamine

EXTENSIONS AND COMMENTARY The rationale for exploring the beta-hydroxylated phenethylamines, especially those with oxygens at the biologically important 3- and 4-positions, has already been presented. Norepinephrine is a 6-hydroxylated phenethylamine with oxygens at these two ring positions. With DME, these are masked as two methyl ethers, and the initials DME stand for 3,4-dimethoxyphenyl-B-ethanolamine. This is an alternate name for 3,4-dimethoxy-B-hydroxyphenethylamine. 

Tyramine, hordenine, 3,4-dimethoxy-j8-phenethylamine, jV-methyl-3,4-dimethoxy-j3-hydroxyphenethylamine (86 amorphous a new natural base), salsoline, salsolidine, tryptamine, abrine, and hypa-phorine (54). 

Chloro-3,4-dimethoxyphenethylamine (1.0 g) was reacted with 0.70 g of p-methoxystyrene oxide to give the hydroxyphenethylamine m.p. 118.5-121°C. This compound (2.16 g) was stirred at room temperature in 15 ml of trifluoroacetic acid with 4 drops of cone, sulfuric acid. After purification over a silica gel column with chloroform, 10% methanol/chloroform as eluates, was obtained 6-chloro-7,8-dimethoxy-l-p-methoxyphenyl-2,3,4,5-tetrahydro-lH-... 

The biosynthetic work on mescaline in the peyote cactus L. williamsii and in the Peruvian cactus T. pachanoi has led to the formulation of biosynthetic pathways according to Scheme 2. A major pathway probably involves decarboxylation of tyrosine followed by hydroxylation to yield dopamine. Dopamine is methylated on the meta hydroxy group to 4-hydroxy-3-methoxyphenethylamine (3-methoxytyramine) which then undergoes hydroxylation to the key intermediate 4,5-dihydroxy-3-methoxyphenethylamine (20). Para-O-methylation of 20 yields 3,4-dimethoxy-5-hydroxyphenethylamine (21), which is the immediate precursor of the main phenolic tetrahydroisoquinolines of peyote. Alternatively, meta-O-methylation yields 3,5-dimethoxy-4-hydroxyphenethylamine (19), which is further efficiently methylated to mescaline. Parallel pathways involving N-methylated compounds probably exist in these cacti (10). 

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