Abstract
The solid-phase synthesis of 2-alkylthio-6H-pyrano[2,3-f]benzimidazole-6- ones (2-alkylthioimidazocoumarins) is described. 7-Fluoro-4-methyl-6-nitro-2- oxo-2H-1-benzopyran-3-carboxylic acid was coupled to Rink amide resin via its carboxyl group. The resin-bound scaffold then underwent aromatic nucleophilic substitution with primary amines, followed by reduction of the nitro group with tin (II) chloride. Subsequent cyclization of the o-dianilino intermediates with thiocarbonyldiimidazole (TCD) afforded resin-bound 1,3-dihydro-2-thioxo-6H- pyrano[2,3-f]benzimidazole-6-ones, which were then S-alkylated with alkyl halides in the presence of N,N-diisopropylethylamine (DIEA). The desired products were obtained in good yield with high purity after trifluoroacetic acid cleavage. The unique spectral properties of 2-alkylthioimidazocoumarins indicate that they may be useful in photodynamic therapy.
Original language | English (US) |
---|---|
Pages (from-to) | 604-610 |
Number of pages | 7 |
Journal | Journal of Combinatorial Chemistry |
Volume | 6 |
Issue number | 4 |
DOIs | |
State | Published - Jul 2004 |
ASJC Scopus subject areas
- Drug Discovery
- Organic Chemistry
- Chemistry(all)
- Discrete Mathematics and Combinatorics