Functionalized ionic liquid as the recyclable catalyst for Mannich-type reaction in aqueous media

A novel functionalized ionic liquid 3-(N,N-dimethyldodecylammonium)propanesulfonic acid hydrogen sulfate ([DDPA][HSO4]) was prepared. The ionic liquid could be used as a Brønsted acid–surfactant-combined catalyst for one-pot three-component Mannich-type reaction at room temperature in water. The heterogeneous catalytic procedure was simple and the catalyst could be reused at least six times without noticeably decreasing the catalytic activity.