Design and exploration of caffeine-based Brönsted acidic ionic liquid (CaffBAIL) for the synthesis of DHPMs,xanthenediones, and acridinediones

A novel caffeine-based acidic ionic liquid was synthesized, characterized, and utilized as an efficient and green catalyst for synthesizing DHPMs, xanthenediones, and acridinediones under solvent-free conditions. The prepared IL showed notable catalytic activity in organic reactions under solvent-free conditions with good reusability of four runs. The advantage of the present protocol is underlined by the originality of the prepared ionic liquid, absence of toxic solvents, high yields of products, and short reaction times.