In the title compound, C(19)H(34)N(+)·Br(-)·H(2)O, the dihedral angle between the trans-planar alkyl side chain and the pyridinium ring is 52.73 (7)°. In the crystal structure, O-H⋯Br, C-H⋯Br and C-H⋯O hydrogen bonds form a network, while the hydro-phobic alkyl chains inter-digitate, forming bilayers.

The synthesis of a variety of 2,3-disubstituted quinolines has been achieved successfully via a one-pot three-component reaction of arylamines, arylaldehydes and aliphatic aldehydes in the presence of butylpyridinium tetrachloroindate(III), [bpy][InCl4], ionic liquid as a green catalyst and solvent. Mild conditions with excellent conversions, and simple product isolation procedure are noteworth...