title: Oligomerization of indole derivatives with incorporation of thiols.
abstract: Two molecules of indole derivative, e.g. indole-5-carboxylic acid, reacted with one molecule of thiol, e.g. 1,2-ethanedithiol, in the presence of trifluoroacetic acid to yield adducts such as 3-[2-(2-amino-5-carboxyphenyl)-1-(2-mercaptoethylthio)ethyl]-1Hindole-5-carboxylic acid. Parallel formation of dimers, such as 2,3-dihydro-1H,1'H-2,3'-biindole-5,5'-dicarboxylic acid and trimers, such as 3,3'-[2-(2-amino-5-carboxyphenyl) ethane-1,1-diyl]bis(1H-indole-5-carboxylic acid) of the indole derivatives was also observed. Reaction of a mixture of indole and indole-5-carboxylic acid with 2-phenylethanethiol proceeded in a regioselective way, affording 3-[2-(2-aminophenyl)-1-(phenethylthio)ethyl]-1H-indole-5-carboxylic acid. An additional product of this reaction was 3-[2-(2-aminophenyl)-1-(phenethylthio)ethyl]-2,3-dihydro-1H,1'H-2,3'-biindole-5'-carboxylic acid, which upon standing in DMSO-d6 solution gave 3-[2-(2-aminophenyl)-1-(phenethylthio)ethyl]-1H,1'H-2,3'-biindole-5'-carboxylic acid. Structures of all compounds were elucidated by NMR, and a mechanism for their formation was suggested.
authors.affiliation: Department of Pharmaceutical Biosciences, Division of Pharmaceutical Pharmacology, Uppsala Biomedical center, Uppsala University, S-751 24, Uppsala, Sweden. fmutulis@osi.lv
authors.forename: Felikss
authors.initials: F
authors.lastname: Mutulis
authors.forename: Adolf
authors.initials: A
authors.lastname: Gogoll
authors.forename: Ilze
authors.initials: I
authors.lastname: Mutule
authors.forename: Sviatlana
authors.initials: S
authors.lastname: Yahorava
authors.forename: Aleh
authors.initials: A
authors.lastname: Yahorau
authors.forename: Edvards
authors.initials: E
authors.lastname: Liepinsh
authors.forename: Jarl E S
authors.initials: JE
authors.lastname: Wikberg
mesh_terms: D019281:Dimerization; D007211:Indoles / Q000737:chemistry*; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D013438:Sulfhydryl Compounds / Q000737:chemistry*
chemical_list: D007211:Indoles; D013438:Sulfhydryl Compounds; C030374:indole
references.citation: J Org Chem. 1998 Oct 2;63(20):7002-7008
references.pmid: 11672324
references.citation: Int J Pept Protein Res. 1990 Sep;36(3):255-66
references.pmid: 2279849
references.citation: J Med Chem. 1972 May;15(5):529-34
references.pmid: 5035276