Synthesis and structure of 4-hy-droxy--iso-propyl-tryptamine (4-HO-NiPT) and its precursors.

The title compound, 4-hy-droxy--iso-propyl-tryptamine () or 4-HO-NiPT (systematic name: 3-{2-[(propan-2-yl)amino]-eth-yl}-1-indol-4-ol), CHNO, was synthesized in three steps from 4-benzyl-oxyindole () (systematic name: 4-phen-oxy-1-indole), CHNO. () was treated with oxalyl chloride and iso-propyl-amine to produce -isopropyl-4-benz-yloxy-3-indole-glyoxyl-amide () {systematic name: 2-[4-(benz-yloxy)-1-indol-3-yl]-2-oxo--(propan-2-yl)acet-amide}, CHNO. () was reduced to generate 4-benz-yloxy--iso-propyl-tryptamine or 4-HO-NiPT, which was characterized as its chloride salt 4-benz-yloxy--iso-propyl-tryptammonium chloride () (systematic name: {2-[4-(benz-yloxy)-1-indol-3-yl]eth-yl}(propan-2-yl)aza-nium chloride), CHNO·Cl. Finally the benzyl group of was removed hydrogenation to generate 4-HO-NiPT. The crystal structures of the title compound and all three synthetic precursors are presented.