1‐n‐Butyl‐3‐Methylimmidazolium Tetrafluoroborate–Promoted Green Synthesis of 5‐Arylidene Barbituric Acids and Thiobarbituric Acid Derivatives

Abstract
The room temperature ionic liquid 1‐n‐butyl‐3‐methylimmidazolium tetrafluoroborate ([bmim]BF4) was used to promote the synthesis of 5‐arylidene barbituric acids and thiobarbituric acid derivatives under the solid‐state conditions of grinding or microwave irradiation without organic solvent. The yields were 77.9–96.2%. It is shown that the proposed method is fast, efficient, and environmentally benign.