Table 3 Compares the efficiency of various methods for solvent-free condensation

1

2 h

0.01 mol

Ammonium bicarbonate

90 °C

91%

K.C

[66]

2

1 h

0.005 mol

(1-((4-chlorophenyl) amino)-1- oxopropan-2-aminium perchlorate)

25 °C

97%

K.C

[67]

3

3 h

0.000006 mol

Zn(pcp)(aip). (H₂O)

25 °C

99%

K.C

[68]

4

1 h

0.2 mol

1-alkyl-2,3 dimethylimida olium salts (NHC) and DBU(0.2)

80 ^oC

72%

B.C

[69]

5

12 h

0.5 mol

Imidazolium salts(NHC)/Cs₂CO₃

30 ^oC

95%

B.C

[70]

6

5 min

0.02 mol

BMICl/NaOMe

150 °C/microwave

97%

B.C

[71]

8

30 min

0.067 mmol

γ-Fe₂O₃-MgO@Ch.F

25 °C

98%

K.C

This work

9

1.5 h

0.092 mmol

γ-Fe₂O₃-MgO@Ch.CN

25 °C

88%

B.C

This work