S.No

Catalyst

Solvent used

Time

Yield (%)

Ref. No

1

KF-Al2O3

C2H5OH

3 - 5 h (reflux)

92

[19]

2

Piperdine

C2H5OH

1 h (reflux)

75

[23]

3

Na2CO3

C2H5OH

3 h (stirrring at RT)

81

[27]

4

InCl3

C2H5OH

7 min (microwave)

90

[31]

5

BF3-SiO2

Solvent free

12 min (reflux)

95

[32]

6

C2H5OH:H2O

C2H5OH

9 h (reflux)

95

[33]

7

p-TsOH

C2H5OH

30 min (ultrasonication)

95

[34]

8

L-Proline

C2H5OH

1 h (reflux)

91

[35]

9

Nano CoFe2O4

C2H5OH

20 min (microwave)

92