Re-Used Pph3 Induced Chemoselective C-C Bond Formation for Synthesis of Novel Indolyl Quinoline Derivatives and their Alkylation Studies by TBAB

PPh3 have been utilized as a novel and efficient chemoselective C-C bond formation, without
alter active chlorine atom. This catalyst using for synthesis of novel Indolyl Quinolines by
Knoevenagel condensation. The reaction of 2-chloroquinoline-3-aldehyde (2) with the active
methylene compound, i.e. 3-cyanoacetylindoles (3), in ethanol at room temperature for 20
min to afford (E)-3-(2-chloroquinolin-4-yl-)-2-(1H-indole-3-carbonyl)acrylonitrile (4).
Subsequently, these were reacted with benzenesulfonyl chloride in CHCl3 the presence of
tetrabutylammoniumbromide (TBAB) as an efficient phase transfer catalyst (PTC) to afford
the corresponding derivatives i.e. (E)-3-(2-chloroquinolin-4-yl-)-2-(1-benzenesulfonyl-1Hindole-
3-carbonyl)acrylonitrile (5). Compound 2 was prepared from acetanilide (1) using a
well-known procedure by Vilsmeier-Hack reaction.