Basic Ionic Liquid Promoted Domino Knoevenagel–Thia‐Michael Reaction: An Efficient and Multicomponent Strategy for Synthesis of 1,3‐Thiazines

An efficient, three-component strategy for synthesis of 1,3-thiazines with high atom economy in one-pot mediated by room temperature basic ionic liquid is described here. The strategy involves basic ionic liquid, [bmim]OH-catalyzed Knoevenagel condensation between ethyl cyanoacetate and aromatic aldehyde and subsequent thia-Michael addition with substituted thioureas. The reaction sequence is smooth and quantitative under ambient temperature. [bmim]OH was recovered and reused four times without any appreciable decrease in its reactivity and product yield.