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New Journal of Chemistry

Nitrogen enriched polytriazine as metal-free heterogeneous catalyst for the

Knoevenagel reaction under mild conditions

Monika Chaudhary and Paritosh Mohanty*

Functional Materials Laboratory, Department of Chemistry, IIT Roorkee, Uttarakhand-

247667, India

E-mail: pmfcy@iitr.ac.in, paritosh75@gmail.com

Electronic Supplementary Material (ESI) for New Journal of Chemistry.This journal is © The Royal Society of Chemistry and the Centre National de la Recherche Scientifique 2018

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N N

N

N N

N NH2

NH2

H2N Cl

Cl

Cl

N

N

N

N N

N

N

N

N

HN NH

HN

HN HN

HNHN

N N

N

N N

NNHNH NHHN

N

N

N

NH

+Melamine Cyanuric Chloride

140 0C, 400W, 30 min

Scheme S1. Reaction scheme for the synthesis of metal-free nitrogen-enriched nanoporous

polytriazine (NENP-1) organocatalyst.

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Figure S1. TEM image of NENP-1 (inset: SAED pattern of NENP-1).

10 20 30 40 50 60 70

Inte

nsity

(a.u

)

Differaction angle (2)Figure S2. XRD pattern of NENP-1.

4

200 400 600 800

0

20

40

60

80

100

Temperature (°C)

Wei

ght (

%)

0

200

400

600

800

DTG

(g/

min

)

Figure S3. TGA/DTG of NENP-1 in air at a heating rate of 5 °C min-1.

5

4000 3500 3000 2500 2000 1500 1000 500

(c)

(b)

Wavenumber (cm-1)

Tran

smitt

ance

(a.u

)

(a)

Figure S4. FT-IR spectra of (a) Benzylidinemalononitrile, (b) Benzaldehyde, and (c)

Malononitrile.

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200 180 160 140 120 100 80 60 40 20 0

CN

CN NENP-1Solvent

RT (30 min)+

O CN

CN

Chemical Shift (ppm)

(a)

12 10 8 6 4 2 0

CN

CN NENP-1Solvent

RT (30 min)+

O CN

CN

(b)

Chemical Shift (ppm)

Figure S5. (a) 13C and (b) 1H NMR spectra of benzylidinemalononitrile.

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Figure S6. (a) GC and (b) MS spectrum of benzylidinemalononitrile.

(b)

(a)

8

CHO

CN

H2C

CN

Solvent

Catalyst 25 °C

NC

CN

Scheme S2. Synthesis of benzylidinemalononitrile from benzaldehyde and malononitrile.

Table S1. Catalytic data of the NENP-1 catalysed model Knoevenagel reaction at various

reaction conditions.

Solvent Volume (mL/mL)

Time (min)

Catalyst amount (wt%)

Yield (%)

THF 1.0/0 30 4.5 37THF/H2O 0.5/0.5 30 4.5 95Methanol 1.0/0 30 4.5 85

Methanol/H2O 0.5/0.5 30 4.5 94Ethanol 1.0/0 30 4.5 87

Ethanol/H2O 0.5/0.5 30 4.5 93H2O 1.0/0 30 4.5 48

Dioxane 1.0/0 30 4.5 41Dioxane/H2O 0.5/0.5 30 4.5 98Dioxane/H2O 0.5/0.5 30 1.9 35Dioxane/H2O 0.5/0.5 90 1.9 46Dioxane/H2O 0.5/0.5 30 8.6 98Dioxane/H2O 0.5/0.5 10 8.6 75Dioxane/H2O 0.5/0.5 02 4.5 45Dioxane/H2O 0.5/0.5 05 4.5 60Dioxane/H2O 0.5/0.5 10 4.5 71

General conditions: Benzaldehyde (1.0 mmol), Malononitrile (1.0 mmol) at 25 °C.

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0 4 8 12 16

20

40

60

80

100

Yiel

d (%

)

Catalyst loading (wt%)

Figure S7. Effect of catalyst loading on yield (%) of benzyldinemalononitrile.

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200 180 160 140 120 100 80 60 40 20 0

CN

CN NENP-1Solvent

RT (30 min)+O

MeO

CN

CNMeO

Chemical Shift (ppm)

(a)

10 8 6 4 2 0

CN

CN NENP-1Solvent

RT (30 min)+O

MeO

CN

CNMeO

Chemical Shift (ppm)

(b)

Figure S8. (a) 13C and (b) 1H spectra NMR spectra of 4-methoxy benzylidinemalononitrile.

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Figure S9. (a) GC and (b) MS spectrum of 4-methoxy benzylidinemalononitrile.

(a)

(b)

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200 180 160 140 120 100 80 60 40 20 0

CN

CN NENP-1Solvent

RT (30 min)+

O CN

CNBrBr

Chemical Shift (ppm)

(a)

10 8 6 4 2 0

CN

CN NENP-1Solvent

RT (30 min)+

O CN

CNBrBr

Chemical Shift (ppm)

(b)

Figure S10. (a) 13C and (b) 1H NMR spectra of 2-bromobenzylidinemalononitrile.

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Figure S11. (a) GC and (b) MS spectrum of 2-bromobenzylidinemalononitrile.

(a)

(b)

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200 180 160 140 120 100 80 60 40 20 0

CN

CN NENP-1Solvent

RT (30 min)+

O

Br

CN

CNBr

Chemical Shift (ppm)

(a)

10 8 6 4 2 0

CN

CN NENP-1Solvent

RT (30 min)+

O

Br

CN

CNBr

Chemical Shift (ppm)

(b)

Figure S12. (a) 13C and (b) 1H NMR spectra of 4-bromobenzylidinemalononitrile.

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Figure S13. (a) GC (b) MS spectrum of 4-bromobenzylidinemalononitrile.

(a)

(b)

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Figure S14. (a) GC and (b) MS spectrum of 2-nitrobenzylidinemalononitrile.

(a)

(b)

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10 8 6 4 2 0

CN

CN NENP-1Solvent

RT (30 min)+

O

NO2

CN

CNNO2

Chemical Shift (ppm)

(a)

200 180 160 140 120 100 80 60 40 20 0

CN

CN NENP-1Solvent

RT (30 min)+

O

NO2

CN

CNNO2

Chemical Shift (ppm)

(b)

Figure S15. (a) 1H and (b) 13C NMR spectra of 2-nitrobenzylidinemalononitrile.

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Figure S16. (a) GC and (b) MS spectrum of 4-nitrobenzylidinemalononitrile.

(a)

(b)

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10 8 6 4 2 0

CN

CN NENP-1Solvent

RT (30 min)+

O

O2N

CN

CNO2N

Chemical Shift (ppm)

(a)

200 180 160 140 120 100 80 60 40 20 0

CN

CN NENP-1Solvent

RT (30 min)+

O

O2N

CN

CNO2N

Chemical Shift (ppm)

(b)

Figure S17. (a) 1H and (b) 13C NMR spectra of 4-nitrobenzylidinemalononitrile.

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10 8 6 4 2 0

CN

CN NENP-1Solvent

RT (30 min)

+OCN

CN

Chemical Shift (ppm)

(a)

200 180 160 140 120 100 80 60 40 20 0

CN

CN NENP-1Solvent

RT (30 min)

+OCN

CN

Chemical Shift (ppm)

(b)

Figure S18. (a) 1H and (b) 13C NMR spectra of α-Napthaldehyde.

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Figure S19. (a) GC and (b) MS spectrum of α-Napthaldehyde.

(a)

(b)

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Table S2. Comparison of experimental conditions for the synthesis of metal-free

heterogeneous organocatalysts and their catalytic performance in Knoevenagel reaction.

Organocatalysts Synthesis conditions Catalysis ReferencesSynthesismethod

Temperature(°C)

Time(h)

Temperature (°C)

Time (min)

Yield (%)

MFCMP-1 Oxidative coupling

polymerization

60 72 25 240 99 S1

JUC-Z12 Oxidative cyclo-dehydrogenation

130 72 25 1440 97 S2

BF-COF-1 Schiff base condensation

120 120 25 600 96 S3

MPU Solvothermal synthesis

150 72 50 840 98 S4

MCN Carbonization 550 3 120 12 95 S5

g-C3N4 Thermal condensation

550 8 40 120 98 S6

PANF Thermal condensation

145 6 70 90 97 S7

NENP-1 Microwave-assisted

condensation

140 0.5 25 30 98 Current work

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