Ionic liquid N-ethylpyridinium hydrogen sulfate as an efficient catalyst for designing indole scaffolds and their antimicrobial behavior

Ionic liquid N-ethylpyridinium hydrogen sulfate has been prepared, characterized and used as an efficient recyclable catalyst for the synthesis of a series of indoles and bis(indolyl)methanes. Latter have been further explored for their potential antimicrobial activity against E coli and Bacillus. The ionic liquid used was recycled in the end and its recovery was facilitated by water. Use of water was beneficial in terms of avoiding organic solvents, providing facile recovery of the products and affording the recycling of the catalyst.