“…A number of processes have been reported for the syntheses which includes 1‐butyl‐3‐methylimidazolium hydroxide . HOAc under microwave irradiation, [Pyrr][HCOO], DABCO, DBU, Er (OTf) 3 , water under MW, [DBU] 2 [EDS], (4‐sulfobutyl)tris(4‐sulfophenyl) phosphonium hydrogen sulfate, Nano‐Fe 3 O 4 /PEG/succinic anhydride, phenylphosphinic acid, p ‐TSA …”