Table 5 Evaluation of various catalysts for the synthesis of dicyanomethylene pyridine in comparison with [Zr-UiO-66-PDC-SO₃H]Cl.

1

SSA

10.0 mg

120

Trace

2

H₂SO₄

10

120

20

3

Fe₃O₄

10.0 mg

120

18

4

p-TSA

10

120

-

5

[PVI-SO₃H]Cl

10.0 mg

120

43

6

MIL-100(Cr)/NHEtN(CH₂PO₃H₂)₂

10.0 mg

120

56

7

Trichloroisocyanuric acid

10

120

-

8

Al(HSO₄)₃

10

120

-

9

Mg(NO₃)₂.6H₂O

10

120

28

10

NaHSO₄

10

120

-

11

NH₄NO₃

10

120

-

12

FeCl₃

10

120

38

13

H₃[p(Mo₃O₁₀)₄]·XH₂O

10

120

-

14

Zn(NO₃)₂·6H₂O

10

120

25

15

KOH

10

120

Trace

16

This work (Method A)

10

20

87