Covalent Modification of Graphene Oxide with Vitamin B1: Preparation

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Covalent Modification of Graphene Oxide with Vitamin B1: Preparation, Characterization and Catalytic Reactivity for Synthesis of Benzimidazole Derivatives hossein ghafuri, Negar Joorabchi, Atefeh Emami, and Hamid Reza Esmaili Zand Ind. Eng. Chem. Res., Just Accepted Manuscript • Publication Date (Web): 14 May 2017 Downloaded from http://pubs.acs.org on May 16, 2017

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Industrial & Engineering Chemistry Research

Covalent Modification of Graphene Oxide with Vitamin B1: Preparation, Characterization and Catalytic Reactivity for Synthesis of Benzimidazole Derivatives Hossein Ghafuri, *1 Negar Joorabchi, 1 Atefeh Emami 1 and Hamid Reza Esmaili Zand 1 1

Catalysis and Organic Synthesis Research Laboratory, Department of Chemistry of Iran University of Science and Technology, Tehran, Iran. 16846_13114, Fax: 982177491204; Tel: 982177240516-7. E-mail: [email protected] KEYWORDS: Graphene Oxide (GO), Vitamin B1 (VB1), Benzimidazole, Heterogeneous Catalysis

ABSTRACT: The GO-VB1 catalyst has successfully synthesized in current research with strong covalent bonds between GO and VB1. This catalyst with covalent bonds has a higher thermal stability in different reaction conditions compare to the other catalysts with nonspecific adsorption to the substrate. GO-VB1 catalyst showed high catalytic activities in benzimidazole synthesis and could be recycled and reused several times without noticeable loss of activity. GO-VB1 is proper for high-yielding preparations and could be used for more catalytic applications. The morphology and chemical structure of GO-VB1 were characterized by X-ray diffraction (XRD), Fourier Transform Infrared spectra (FT-IR), Scanning Electron Microscope (SEM), Energy Dispersive X-ray spectroscopy (EDS), Atomic Force Microscope (AFM) and Thermogravimetric Analyses (TGA).

1.

Introduction:

For many years, carbonaceous materials were fascinating to researchers due to their specific properties.5-12 Graphene, As a result of increasing global warming, environmenas an important group of carbon based materials, draw sigtally friendly materials have turned into a topic of imnificant attention among scientists as a result of its outportant research interest.1 The development of effective standing properties such as high stability, charge-carrier synthetic methodologies for organic reactions in the presmobility,13 thermal conductivity,14 electrical conductivity15 ence of eco-friendly reagents is a significant challenge.Vitand a large theoretical specific surface area 16,17 . These apamin B1 (VB1), thiamine, is the first recognized naturally plications are caused by the honeycomb crystal lattice of occurring organic compound which shows a great number graphene and sp2 hybridized carbon atoms in its surface. A of indispensable roles in biology and green chemistry. VB1 remarkable synthetic approach to synthesis biocatalysts is has absorbed massive attentions of researchers due to its 2,3 linking the functionalized graphene to the biomaterialsby water compatibility, non-toxicity and ease of handling. In covalent attachment to graphene surface results in produc1960’s, Ronald Breslow suggested that VB1 could be used as ing biocatalysts with high surface area.18, 19. These types of a catalyst in biochemical acyloin condensations and also compounds with covalent bonds has a higher thermal stafunctions as a coenzyme.4 Other studies have proposed bility in different reaction conditions compared with the that VB1 has appropriate catalytic activity to transform alones with nonspecific adsorption bonds to the substrate. dehydes to acyloins in buffered aqueous solutions. Also Our research revealed that modification of graphene oxide VB1 and its derivatives can be employed as the asymmetric (GO) with thionyl chloride and producing chlorinated GO biocatalysts. Other catalytic activities of VB1 are in made a convenient support for attaching VB1 by covalent Knoevenagel condensation, Michael addition and cycliza2-4 bond to its surface to gain solid and heterogeneous biocattions. alyst. Moreover, the obtained results indicated that the Many reactions by biocatalysts were reported in recent process of modification could considerably enhance the years. Progressive applications of biocatalysts have atperformance of VB1. tracted the attention of researchers to study their interacConsidering the applicability of biocatalysts in generattions with solid supports, which will affect biocatalysts ing carbon–carbon and carbon–heteroatom bonds, we deproperties. Also solid supports convert biocatalysts from cided to link GO and VB1 by covalent bond. Then we study homogeneous catalyst to heterogeneous catalysts with easthe application of GO-VB1 as a biocatalyst in the condenier separation process. sation of o-phenylenediamine with aldehyde to afford 2ACS Paragon Plus Environment


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substituted benzimidazoles -as an important class of heterocyclic compounds in the structure of several drugs like albendazole, mebendazole and triclabendazole- (scheme 1). Efficient synthesis of 2-substituted benzimidazoles was achieved by various types of aldehyde and o-phenyenediamine under mild conditions in EtOH at room temperature in high yields using GO-VB1 as a reusable and green biocatalyst.

NH2

O C

1

H R2

NH2

2

R1

GO-VB1

H N

EtOH

N R2

R1

3a-r

Scheme 1. Synthesis of benzimidazol derivatives 3a-3r.

2.

Experimental Section

2.1. Material All solvents, reagents and chemicals were purchased from Merck and Aldrich. Reactions and products were characterized by standard techniques. IR spectra were took on a Shimadzu IR-470 spectrometer, NMR spectra were took on a Bruker DRX-500 Avance spectrometer, XRD measurements were took on a JEOL JDX–8030 (30 kV, 20 mA), EDX spectra were took on a Numerix DXP–X10P, FE-SEM images were took on a Sigma Zeiss and melting points were took on an Electrothermal 9100 apparatus.

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washed with ethanol. Precipitated product was heated to 70oC in oven for 24h to dry. 2.2.3. Preparation of Benzimidazole The efficiency of GO-VB1 as a catalyst was examined in the synthesis of benzimidazoles. For this purpose, 1 mmol of o -phenylenediamine, 1.2 mmol of 3-nitrobenzaldehyde and 0.03 g of GO-VB1 were added to 4 ml ethanol. The obtained mixture was placed at room temperature and stirred till the reaction completed. Completion of the reaction was followed by TLC. To separate the catalyst, reaction mixture was centrifuged and filtrated. After separation the catalyst by this method, the solution of the reaction was first heated and then cooled to 0oC to precipitate by the shocking process. After precipitation, the mixture was placed in 0 oC for 24 h for better crystallization. The final product was filteredand washed by ethanol. 3. Result and discussion 3.1. Characterization of catalyst The synthesized GO-VB1 catalyst was thoroughly characterized by FT-IR, EDX, SEM, TEM and TGA analysis. The FT-IR spectra of pure GO shows peaks in the range of 3500– 2500 cm−1 attributed to the acidic and alcoholic groups. the stretching peaks of C=O appeared at 1722 cm−1 , stretching peaks of C=C at 1623 cm−1 and peaks in 1224 cm−1 and 1051 cm−1 related to C-O bond of ether and epoxide groups, respectively. In the FT-IR of GO-VB1, peaks in 3440 and 3420 cm−1 attributed to the hydrogens of NH2, stretching peaks of C=O appeared at 1700 cm−1 and peak at 1620 cm−1 was assigned to stretching frequency of C=N (Figure 1).

2.2. Methods 2.2.1. Preparation of GO GO was synthesized by modified Hummer’s method. Particularly, 4 g of graphite and 2 g of NaNO3 were added to the flask containing 95 ml H2SO4 98%. The mixture was sonicated at 65 oC for 30 min, then stirred for 1 h at 20 oC. To this mixture, 12 g of KMnO4 was added slowly under sonication. The mixture was sonicated at 80 oC for 30 min, then stirred for another 1 h at 95 oC. Resulted mixture was dispensed into 250 mL of DI-water. After heating at 100 oC for 1 h, brown mixture was shaped. The mixture was poured into 450 mL of DI-water, then H2O2 5% was added dropwise to it to obtain yellow brown solution. After adjusting the pH to 6 by adding HCl 5%, the mixture was stirred for another 10 minutes at room temperature and then filtered. By adding 5mL of H2O2 30% and 0.1 mL of AgNO3 0.1 M to the filtrate solution, removal of manganese and Cl - was verified. The obtained dark brown powder was dried for 24 h at 60oC in vacuum oven.

Go 100

80 60 40 20 0

5000

4000

2.2.2. Preparation of GO-VB1 0.8 g of GO was added to 45 ml DMF and dispersed under sonication for 2h. To this mixture, 12 ml of thionyl chloride was added and refluxed for 24 h. 6.01 g of thiamine and 10 ml of NEt 3 was added to this reaction mixture in an ice bath during stirring and was refluxed for 3 days at 120oC. The final product was separated by centrifuge, filtered and

ACS Paragon Plus Environment

3000

2000

1000

0

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Inte nsity(R.B.T unit)

GO-VB1

95 90 85 80

500 400 300 200 100 0 5

755000

4000

3000

2000

1000

25

45

65

85

Direction angle(2θ)

0

Fig. 1. FT-IR spectra of GO and GO-VB1

Fig. 2. XRD pattern of graphite, GO and GO-VB1

The XRD patterns of pure GO shows the existence of oxygen groups. Comparison between the patterns of graphite and GO completely indicates that entering the oxygen groups in the structure of graphite increased the space between graphite sheets. This increase is about 0.785 nm and can be measured from Brag’s rule. Increasing the space between the sheets according to nλ=2d sinθ resulted in the decrease of 2θ angle. Also after oxidation the graphite, in 11.8o a new peak can be seen in the XRD pattern of GO. In the XRD pattern of GO-VB1, GO peaks entirely eliminated from the pattern and an obvious peak in 7.8o can be seen. Also due to the existence of multitudinous functional groups, a peak in 24o illustrate the formation of GO-VB1 (Figure 2).

The EDS spectrum for GO shows that the ratio of oxygen groups to carbon in the structure of GO is 1:3. Also the existence of trace amounts of sulfur in the structure is because of the sulfonating process. In the EDS spectrum of GO-VB1, existence of nitrogen and sulfur is because of the presence of thiamine which was covalently attached toGO. Amount of nitrogen is 9.49 % and amount of sulfur is 2.63%. Due to the structure of thiamine, ratio of nitrogen to sulfur is 4:1 which completely concur with EDS analysis (Figure 3).

Intensity (R.B.T unit)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


11.8 0 , 1283

26.5 0 , 7649 (002)

Graphite

42.4 0 , 195 54.5 0 , 273 (004)

5 10 15 20 25 30 35 40 45 50 55 60 65 70 75 80

Diraction Angle )2θ(

Fig. 3. EDS spectra of GO-VB1

The morphology of GO nanosheets were studied by SEM analysis. SEM image of pure GO nanosheets shows that because of deformation through the exfoliation and restacking processes, crumpled and rippled structure was gained. Also from the SEM analysis of GO-VB1, due to the addition of thiamine to the structure of GO, space between the sheets was increased (Fig. 4).



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Fig. 4.SEM images of GO-VB1

AFM images of GO-VB1 shows that after functionalizing GO, thickness of sheets was increased. From previous reports, thickness of GO is between 1.2-1.8 nm which after addition of thiamine, this amount comes to 22.5 for GOVB1 (Fig. 5).

Fig. 6. TGA analysis of graphene, GO and GO-VB1

3.2. Optimization of the reaction conditions To study the synthesis of benzimidazole derivatives with different catalytic systems, the reaction of 4-chloro benzaldehyde and o -phenylenediamine were carried out in the absence of catalyst at room temperature. It was noted that in the absence of catalyst, the product was formed in long reaction times. To find the suitable reaction conditions, the reaction was performed in the presence of GO and VB1 in EtOH at room temperature. The results revealed that the yield of the reaction in the presence of GO and vitamin B1 is 60 and 80 %, respectively. After that, we carried out the reaction in the presence of GO-VB1 in EtOH and room temperature. It was found that the reaction was completed within 96% yield. To compare the effects of GO-VB1 as a catalyst to reported catalysts, results for optimized conditions of different catalysts including Nano-ZnO,20 Zeolite,21 Scolecite,22 Nano-alumina,20 Fe3O4/Collagene23 and GO-VB1 were demonstrated in Table 1. According to these results, GOVB1 was found to be the most effective catalyst with high yield product and short reaction time among them.

Fig. 5. AFM images of GO-VB1

As shown in Figure 6 from TGA analysis, GO-VB1 starts to lose mass about 4.56% upon heating at around 200oC that is because of the elimination of volatile elements. This amount for GO is about 30% below 200oC. The results from TGA show the losing mass is 31.64% around 400-550oC which because of the decomposition of functional groups.


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Ref.

Yield

Nano-

Temp.oc

Catalyst

1

Solvent

Time (min)

EtOH

78

95

68

20

Zeolite

dioxane

100

300

69

21

3

Scolecite

EtOH

70

45

91

22

4

Nano-

EtOH

78

90

74

20

EtOH

25

12

78

23

EtOH

25

30

95

our work

ZnO 2

alumina 5

Fe3 O4/ Collagene

6 GO-VB1

To discover the scope of the benzimidazole synthesis, variety of o -phenylenediamines and aldehydes were used and the reactions were carried out under optimized conditions. The yields of the reactions were found to be between 85% to 95% and indicated that functional groups did not significantly affect the yield of product. As shown in Table 2, 18 kind of benzimidazoles were gained with accurate melting points24-34 and all of them have short reaction times and high yields in moderate conditions. 3.3 Recyclability of the catalyst We investigated the recyclability of GO-VB1. The catalyst was isolated by simple filtration. As shown in Figure 7, GOVB1 was used again in the optimized reactions 5 times and giving 93, 90, 89 and 87 % yields of products. The results confirmed that GO-VB1 could be applied as a recyclable catalyst without great loss of activity.

Table. 2. Derivatization of the reaction of 4-chloro benzaldehyde and o -phenylenediaminea

Entry

Table 1. Comparing GO-VB1 catalyst to reportedmethods for the synthesis of benzimidazole derivatives.

Entry

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60


R1

R2

Product

Time (min)

Yield (%)

Observed mp oC 298300

Ref. mp oC

1

4-Cl

H

3a

30

95

2

4NO 2

H

3b

30

95

3

H

H

3c

35

90

4

4OMe

H

3d

45

87

230232

223226 24

5

3NO 2

H

3e

30

95

200202

20324

6

3,4OH

H

3f

47

85

254-

258-

257

26026

7

2OH

H

3g

47

85

240242

24224327

8

3-Cl

H

3h

30

95

225-

230-

228

23128

9

3-Br

H

3i

35

90

227-

223-

230

22429

10

4OMe

3Me

3j

45

90

11

H

3Me

3k

35

90

12

2-Br

3Me

3l

35

90

172

13

2OH

3Me

3m

47

85

245247

14

4NO 2

3Me

3n

30

95

15

3NO 2

3Me

3o

30

93

16

3-Cl

3NO 2

3p

35

93

17

4NO 2

3NO 2

3q

40

90

18

H

3NO 2

3r

45

87

a

303304 288290

169171 232233

30024 304306 25 29324

17124 236 24 16817130 24024227

235-

240-

238

24231

197-

200-

198

20132

218-

220-

219

2223 3

225-

222-

227

22434

198200

20324

Reaction conditions; o-Phenelyenediamine (1 mmol), benzaldehyde (1.2 mmol), GO-VB1 (30 mg).



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Fig. 7. Recyclability of GO-VB1 Conclusion To examine synthesized GO-VB1 as a catalyst, we used an advantageous procedure to synthesis benzimidazole derivatives. Optimization of the reactions were resulted in an overall yields of 85-95%. The workups of the reactions were noticeably simple and the final products did not need any additional purifications. As a result, GO-VB1 is proper for high-yielding preparations and could be used for more catalytic applications.

ASSOCIATED CONTENT Supporting information contains texts that describe the list of materials and characterization analysis. This material is available free of charge via the Internet at http://pubs.acs.org.

AUTHOR INFORMATION Corresponding Author * The Fax: 982177491204; Tel: 982177240516-7; E-mail: [email protected]

Notes The authors declare no competing financial interest.

ACKNOWLEDGMENT The authors gratefully acknowledge the support from the Research Council of the Iran University of Science and Technology.


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REFERENCES 1

2 3

4 5

6 7 8 9 10 11 12

13

14 15 16 17

18

19

20

21 22 23

Liu, J., Lei, M., Hu, M. T hiamine hydrochloride (VB1):an efficient promoter for the one-pot synthesis of benzo[4,5]imidazo[1,2-a]pyrimidine and [1,2,4]triazolo[1,5-a]pyrimidine derivativesin water medium. Green Chem . 2012,14, 840. Chen, Y., Zhang, X. P. Vitamin B12 derivatives as natural asymmetric catalysts: enantioselective cyclopropanation of alkenes.J. Org. Chem . 2004, 69, 2431. ISiddiqui, I. R., P. Rahila, P., Srivastava, A. Synthesis of fused pyridines in the presence of thiamine hydrochloride as an efficient and reusable catalyst in aqueous conditions. New J. Chem . 2013, 37, 3798. Breslow, R. On the mechanism of thiamine action, evidencefrom studies on model systems. JACS, 1958, 80, 3719. Liang, H. W., Zhuang, X., Bruller, S., Feng, X., Mullen, K. Hierarchically porous carbons with optimized nitrogen doping as highly active electrocatalysts for oxygen reduction. Nat. Commun.2014, 5, 4973. Kroto, H. W., Heath, J. R., Obrien, S. C., Curl, R. F., Smalley, R. E. C 60: buckminsterfullerene. Nature. 1985, 318, 162. Lijima, S. Helical microtubules of graphitic carbon. Nature. 1991, 354, 56. Fasolino, A., Los, J. H., Katsnelson, M. I. Intrinsic ripples in graphene. Nat. Mater. 2007, 6, 858. Geim, K., Novoselov, K. S. T he rise of graphene. Nat. Mater.2007, 6, 183. Rao, C. N. R., Sood, A. K, Subrahmanyam, K. S., Govindaraj, A. Graphene: the new two‐dimensional nanomaterial. Angew.Chem. Int. Ed., 2009, 48, 7752. Eizenberg, M., Blakely, J. M. Carbon monolayer phase condensation on Ni (111). Surf. Sci. 1970, 82, 228. K. S. Novoselov, K. S., K. S. Geim, K. S., S. V. Morozov, S. V., D. Jiang, D., Zhang, Y., Dubonos, S. V., Grigorieva1, I. V., Firsov, A. A. Electric field effect in atomically thin carbon films. Science. 2004, 306, 666. Ortila, M., Faugeras, C., Plochocka, P., Neugebauer, P., Martinez, G., Maude, D. K., Barra, A. L., Sprinkle, M., Berger, C., de Heer, W. A., Potemski, M. Approaching the Dirac point in high-mobility multilayer epitaxial graphene. Phys. Rev. Lett. 2008, 101, 267601. Balandin, A. A., Ghosh, S., Bao, W., Calizo, I., T eweldebrhan, D., Miao, F., Lau, C. N. Superior thermal conductivity of single-layer graphene. Nano Lett. 2008, 8, 902. Du, X., Skachko, I., Barker, A., Andrei, E. Y. Approachingballistic transport in suspended graphene. Nat. Nanotechnol. 2008, 3, 491. Zhu, Y., Murali, S., Cai, W., Li, X., Suk, J. W., Potts, J.R.Graphene and graphene oxide: synthesis, properties, and applications. Adv. Mater. 2010, 22, 3906. Weber, C. M., Eisele, D. M., Rabe, J. P., Liang, Y., Feng, X., Zhi, L., Mullen, K., Lyon, J. L., Williams, R., Bout, D. A. V., Stevenson, K. J. Graphene‐based optically transparent electrodesfor spectroelectrochemistry in the UV–Vis region. Small. 2011, 6, 184. a) Han, T ., Lee, Y., Choi, M., Woo, S., Bae, S., Hong, B., Ahn, J., Lee, T . Extremely efficient flexible organiclight-emitting diodes with modified graphene anode. Nature Photonics.2012, 6, 105. b) Ghafuri H., T alebi, M. Water-Soluble Phosphated Graphene: Preparation, Characterization, CatalyticReactivity,andAdsorption Property. Ind. Eng. Chem. Res. 2016, 55 , 2970–2982. Khan, M., T ahir, T ., Adil1, S. F., Khan, H. U., Rafiq M., Siddiqui, H., Al-warthan, A. A., T remel, W. Graphene based metalandmetal oxide nanocomposites: synthesis, properties and their applications. J. Mater. Chem. A. 2015, 3, 1875. T eimouri A., Chermahini, A. N., Salavati, H., Ghorbanian, L. An efficient and one-pot synthesis of benzimidazoles, benzoxazoles, benzothiazoles and quinoxalines catalyzed via nano-solid acidcatalysts. J. Mol. Catal. .A: Chemical. 2013, 373, 38. Heravi, M. M., T ajbakhsh, M., Ahmadi, A. N., Mohajerani,B. Zeolites. Efficient and eco-friendly catalysts for the synthesisof benzimidazoles. Monatsh. Chem. 2006, 137, 175. Gadekar, L. S., Arbad, B. R., Lande, M. K. Eco-friendly synthesis of benzimidazole derivatives using solid acid scolecite catalyst . Chin. Chem. Lett. 2010, 21, 1053. Ghafuri, H., Esmaili, E., T alebi, M. Fe3 O4 @ SiO2 /collagen: An efficient magnetic nanocatalyst for the synthesis of benzimidazole and benzothiazole derivatives. Comp. Ren. Chim.. 2016, 19, 942.

24

25 26

27

28

29

30

31

32

33 34

Bahrami, K., Khodaei, M. M., Nejati, A. Synthesis of 1, 2-disubstituted benzimidazoles, 2-substituted benzimidazoles and 2-substituted benzothiazoles in SDS micelles. Green Chem ., 2010 , 12, 1237 Azizian, J., T orabi, P., Noei, J. Synthesis of benzimidazo les and benzoxazoles using T iCl3 OT f in ethanol at room temperature.Tet. Lett., 2016 , 57, 185. Naeimi, H., Babaei, Z. A Mild and Simple One‐pot Synthesisof 2‐ Substituted Benzimidazole Derivatives Using DDQ as an Efficient Oxidant at Room T emperature, journal of the Chinese chem.soci., 2015, 62, 41. Vázquez, G. N., Diaz, H. M., Soto, S. E., Piedra, M. T ., Rivera, I. L., T lahuext, H., Muñiz, O. M., Gómez, H. T . Microwave Assisted One Pot Synthesis of 2(Substituted phenyl) 1H benzimidazoleDerivatives. Syn. Comm., 2007, 37, 2815. Chen, Zh., Li, H., Cao, G., Xu, J., Miao, M., Ren, H. Copper-Catalyzed Double C–N Bond Formation for the Synthesis of Diverse Benzimidazoles from N-Alkyl-2-iodoaniline and Sodium Azide. Synlett, 2017, 28, 504. Mahesh, D., Sadhu, P., Punniyamurthy, T . Copper (I)-Catalyzed Regioselective Amination of N-Aryl Imines Using T MSN3 and T BHP: A Route to Substituted Benzimidazoles. JOC., 2015 , 80, 1644. Zaika, L. L., Joullié, M. M. 1,2,3-benzotriazines. II. Reactionsof benzimidazo[1,2-c][1,2,3]benzotriazines and naphth[1′,2′ (2′,1′):4,5]imidazo[1,2-c][1,2,3]benzotriazine. J.Het.Chem.., 1966, 3, 444. Shaikh, K. A., Patil, V. A., Shaikh, P. A. An Efficient andConvenient Synthesis of Imidazolines and Benzimidazoles via Oxidation of Carbon ‐ Nitrogen Bond in Water Media. Chinese J. Chem ., 2012 , 30, 924. Keurulainen, L., Salin, O., Siiskonen, A., Kern, J. M., Alvesalo, J., Kiuru, P., Maass, M., Yli-Kauhaluoma, J., Vuorela, P. Design and synthesis of 2-arylbenzimidazoles and evaluation of their inhibitory effect against Chlamydia pneumoniae. J. Med. Chem ., 2010 , 53, 7664. Sandera, G., Isensee, R. W., Joseph, L. Derivatives of 2-Phenylbenzimidazole, JACS, 1954, 76, 5173. Mahdavinia, G. M., Rostamizadeh, Sh., Amani, A. M., Sepehrian, H. Fast and efficient method for the synthesis of 2-arylbenzimidazoles using MCM-41-SO3H. Het. Comm., 2012, 18.



Graphical abstract

Covalent Modification of Graphene oxide with Vitamin B1: Preparation, Characterization and Catalytic Reactivity for Synthesis of Benzimidazole Derivatives Hossein Ghafuri, *1 Negar Joorabchi, 1 Atefeh Emami 1 and Hamid Reza Esmaili Zand 1 1

Catalysis and Organic Synthesis Research Laboratory, Department of Chemistry of Iran University of Science and Technology, Tehran, Iran. 16846_13114, Fax: 982177491204; Tel: 982177240516-7. E-mail: [email protected] KEYWORDS: Graphene Oxide (GO), Vitamin B1 (VB1), Benzimidazole, Heterogeneous Catalysis 2Cl

2Cl

NH3

N

H2N

N

N

NH3

N

N S

Ar

C

S

O

C

O

N

H

H

H2N

H

O

Ar

H

O

O

O

-H2O

(3) N

2Cl

N

NH3 N

Air

Ar

H N

N

Ar

O N H

N H

(6)

O

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60

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S H N HC

(5)

Ar


H2N

8

Covalent Modification of Graphene Oxide with Vitamin B1: Preparation

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