5-Benzyloxyindole

Chemical Properties

Off-white to beige powder

Uses

5-Benzyloxyindole is used as reagent/reactant in regioselective preparation of CF3-β-tryptamine derivatives via base-free thermal ring-opening reaction of N-nosyl-2-CF3-aziridine with indoles.

Uses

• Reactant in regio- and stereoselective morpholine-catalyzed direct C-3 alkenylation with α,β-unsaturated aldehydes
• Reactant in selective debenzylation of protective groups using SiliaCat-palladium under mild reaction conditions
• Reactant in metal-free Friedel-Crafts alkylation reactions
• Reactant in preparation of protein kinase (PKC) inhibitors
• Reactant in preparation of indole/quinoline carbothioic acid amide derivatives

Uses

Reactant in regio- and stereoselective morpholine-catalyzed direct C-3 alkenylation with α,β-unsaturated aldehydes Reactant in selective debenzylation of protective groups using SiliaCat-palladium under mild reaction conditions Reactant in metal-free Friedel-Crafts alkylation reactions Reactant in preparation of protein kinase (PKC) inhibitors Reactant in preparation of indole/quinoline carbothioic acid amide derivatives.

Synthesis

The reduction reaction of 4-benzyloxy-2-(2-pyrrolidinylvinyl)nitrobenzene was carried out using (E)-1-(5-(benzyloxy)-2-nitrophenylvinyl)pyrrolidine as a starting material, with reference to the method of Example 32, in the presence of 5% rhodium/carbon powder and a metal compound such as ferrous acetate (II), nickel nitrate (II) or cobalt acetylacetonate (III) as a catalyst. The results of the experiments are listed in Table 5 and show that in the presence of the reducing agent of the present invention, the yield of 5-benzyloxyindole was significantly increased while the yield of 5-hydroxyindole as a by-product was decreased as compared to the counterpart 4.

Purification Methods

It is recrystallised from *C6H6/pet ether or pet ether. The picrate forms red crystals from *C6H6 and has m 142-143o. [Burton & Leong Chem Ind (London) 1035 1953, Ek & Witkop J Am Chem Soc 76 5579 1954, fluorescence: Bridges & Williams Biochem J 107 225 1968, Beilstein 27 III/IV 1758.]

References

[1] Patent: EP1541582, 2005, A1. Location in patent: Page/Page column 39
[2] Tetrahedron Letters, 2006, vol. 47, # 6, p. 969 - 972