Table of Contents
CONTENT PAEG
CHAPTER ONE…………………………………………………………………………………….. 1
INTRODUCTION………………………………………………………………………………….. 2
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Activated carbon……………………………………………………………….. 2
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Activated carbon surface chemistry ……………………….. 3
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Acidic surfaces ………………………………………. 3
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Basic surfaces ………………………………………… 4
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Carbon materials as catalysts …………………………………. 6
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Solid acid catalyst ………………………………….. 7
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Carbon materials as supports………………………………….. 8
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Carbon nanotubes…………………………………………………………….. 19
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Functionalization of carbon nanotubes………………….. 20
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Magnetic carbon nanotubes…………………………………… 26
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Heteroaromatic compounds……………………………………………… 27
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Benzimidazole ……………………………………………………… 28
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Preparation of benzimidazoles……………….. 30
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Different methods for synthesis of benzimidazoles 32
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Benzoxazole………………………………………………………….. 36
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Preparation of benzoxazoles………………….. 37
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Benzotiazole………………………………………………………….. 42
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Preparation of benzothiazoles………………… 43
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CHAPTER TWO………………………………………………………………………………….. 50
EXPERIMENTAL………………………………………………………………………………… 51
2.1. Instrumentation, analyses and starting material……………………. 51
2.2. Preparation of amine functionalization of activated carbon…. 52
2.3. Preparation Salicylaldehyde-based Schiff base of amino functionalizedactivated carbon……………………………………………………………………………………………………. 52
2.4. Preparation of copper(II)-2-ethyliminomethyl-phenol complex supported on activated carbon…………………………………………………………………………………………. 53
2.5. Formation of zwitterions on activated carbon by direct reaction of the amine functionalization of activated carbon with acids ……………………….. 53
2.6. Synthesis and purification of MWCNTs……………………………….. 54
2.7. Formation of Fe3O4-doped MWCNTs…………………………………… 54
2.8. General procedure for the preparation of 2-substituted benzimidazole in the presence of copper complex as catalyst…………………………………………………………. 55
2.9. General procedure for the preparation of 2-substituted benzimidazoles in the presence of the catalyst 5……………………………………………………………………………….. 55
2.10. General procedure for the preparation of 2-substituted benzimidazoles in the presence of the Fe3O4-MWCNTs as catalyst………………………………………………. 56
2.11. Physical and spectroscopic data of 2-arylbenzimidazoles derivatives 56
2.12. General procedure for the preparation of 2-substituted benzothiazoles in the presence of the catalyst 5…………………………………………………………………………… 66
2.13. General procedure for the preparation of 2-substituted benzothiazoles in the presence of the Fe3O4-MWCNTs as catalyst………………………………………………. 67
2.14. Physical and spectroscopic data of 2-arylbenzothiazoles derivatives 67
2.15. General procedure for the preparation of 2-substituted benzoxazoles in the presence of the Fe3O4-MWCNTs as catalyst…………………………………………………… 73
2.16. Physical and spectroscopic data of 2-arylbenzoxazoles derivatives 74
CHAPTER THREE………………………………………………………………………………. 80
RESULTS AND DISCUSSION……………………………………………………………… 81
3.1. Preparation of copper(II)-2-ethyliminomethyl-phenol complex supported on activated carbon……………………………………………………………………… 81
3.2. Formation of zwitterions on activated carbon as new catalysts in the synthesis of benzimidazoles and benzothiazole……………………………………………….. 86
3.2.1. Synthesis of benzimidazole using catalyst 5…………… 88
3.2.2. Synthesis of benzothiazole using catalyst 5……………. 96
3.3. Fe3O4-MWCNTs as a heterogeneous catalyst………………………… 102
3.3.1. Formation of Fe3O4-MWCNTs……………………………….. 104
3.3.2. Characterization of Fe3O4-MWCNTs……………………… 104
3.3.3. One-pot synthesis of benzimidazole using Fe3O4-MWCNTs catalyst 109
3.3.4. One-pot synthesis of benzothiazole using Fe3O4-MWCNTs
atalyst……………………………………………………………………………… 114
3.3.5. One-pot synthesis of benzoxazole using Fe3O4-MWCNTs
catalyst……………………………………………………………………………. 118
3.3.6. Recyclability of the Fe3O4– MWCNTs catalyst………. 121
3.4. Conclusion…………………………………………………………………………….. 122
References…………………………………………………………………………………………… 120
Spectral Data………………………………………………………………………………………. 134
List of Figures
Figures No. |
Content |
Page |
Figure 1.1 |
Acidic and basic surface functionalities on a carbon basal plane |
5 |
Figure 1.2 |
Types of nitrogen surface functional groups: (a) pyrrole, (b) primary amine, (c) secondary amine, (d) pyridine, (e) imine, (f) tertiary amine, (g) nitro, (h) nitroso, (i) amide, (j) pyridone, (k) pyridine-N-oxide, (l) quaternary nitrogen |
6 |
Figure1.3 |
Structure of graphene (a), Single-Walled (SWNT) (b) and Multi-Walled (MWNT) carbon Nano Tubes (c) |
20 |
Figure 1.4 |
Examples of biologically benzo fused imidazoles, oxazoles, and thiazoles |
28 |
Figure 1.5 |
Benzimidazol |
29 |
Figure 1.6 |
Examples of biologically important substituted 2-arylbenzimidazoles |
29 |
Figure 1.7 |
Benzoxazole |
36 |
Figure 1.8 |
Benzothiazol |
42 |
Figure 3.1 |
Preparation of amine functionalization of activated carbon |
82 |
Figure 3.2 |
Perparation of salicylaldehyde-based Schiff base of amino functionalized activated carbon |
82 |
Figure 3.3 |
Perparation of copper(II)-2-ethyliminomethyl-phenol complex supported on activated carbon |
83 |
Figure 3.1 |
FT-IR spectrum of :a) Activated carbon b)Amine functionalization of activated carbon , c) Schiff base of amino functionalized activated carbon and d) Cu complex supported on activated carbon |
83 |
Figure 3.2 |
Formation of zwitterions on activated carbon |
86 |
Figure 3.3 |
FT-IR spectrum of :a) Catalyst 2 , b) Catalyst 3 , c) Catalyst 4 and d)Catalyst 5 |
87 |
Figure 3.4 |
The plausible proposed mechanism for synthesis of 2-substituted benzimidazoles usingThe catalyst 5 |
95 |
Figure 3.5 |
The plausible mechanism involved inThe formation of 2-aryl-1-arylmethyl-1H-1,3-benzimidazoles. |
96 |
Figure 3.6 |
SEM image ofThe CVD-synthesized MWCNTs. |
104 |
Figure 3.7 |
Thermogram ofThe synthesized iron-doped MWCNTs. |
105 |
Figure 3.8 |
TEM image of Fe3O4-doped MWCNTs. |
106 |
Figure 3.9 |
Raman spectra of MWCNTs and Fe3O4-doped MWCNTs. |
107 |
Figure 3.10 |
FT-IR spectra of a) actiavted MWCNTs and b) Fe3O4-doped MWCNTs. |
108 |
Figure 3.11 |
Catalyst recyclability studies for 2-(4-chlorophenyl)-1H-benzimidazole, 2-(4-chlorophenyl)benzothiazole in ethanol at room temperature, and for 2-(4-chlorophenyl)benzoxazole in xylene at 150°C (reaction time for benzimidazole, benzothiazole and benzoxazole , respectively, are 0.5, 2 and 2.5 hours) |
122 |
Figure 1 |
The 1H NMR and 13C NMR spectra of compound 36 |
123 |
Figure 2 |
The Mass and IR spectra of compound 36 |
125 |
Figure 3 |
The 1H NMR and 13C NMR spectra of compound 4 |
126 |
Figure 4 |
The Mass and IR spectra of compound 4 |
127 |
Figure 5 |
The 1H NMR and 13C NMR spectra of compound 12 |
128 |
Figure 6 |
The Mass and IR spectra of compound 12 |
129 |
Figure 7 |
The 1H NMR and 13C NMR spectra of compound 13 |
130 |
Figure 8 |
The Mass and IR spectra of compound 13 |
131 |
Figure 9 |
The 1H NMR and 13C NMR spectra of compound 14 |
132 |
Figure 10 |
The Mass and IR spectra of compound 14 |
133 |
Figure 11 |
The 1H NMR and 13C NMR spectra of compound 10 |
134 |
Figure 12 |
The Mass and IR spectra of compound 10 |
135 |
Figure 13 |
The 1H NMR and 13C NMR spectra of compound 15 |
136 |
Figure 14 |
The Mass and IR spectra of compound 15 |
137 |
Figure 15 |
The 1H NMR and 13C NMR spectra of compound 16 |
138 |
Figure 16 |
The Mass and IR spectra of compound 16 |
139 |
Figure 17 |
The 1H NMR and 13C NMR spectra of compound 37 |
140 |
Figure 18 |
The Mass and IR spectra of compound 37 |
141 |
Figure 19 |
The 1H NMR and 13C NMR spectra of compound 38 |
142 |
Figure 20 |
The Mass and IR spectra of compound 38 |
143 |
Figure 21 |
The 1H NMR and 13C NMR spectra of compound 17 |
144 |
Figure 22 |
The 1H NMR and 13C NMR spectra of compound 18 |
145 |
Figure 23 |
The Mass and IR spectra of compound 18 |
146 |
Figure 24 |
The 1H NMR and 13C NMR spectra of compound 19 |
147 |
Figure 25 |
The Mass and IR spectra of compound 19 |
148 |
Figure 26 |
The 1H NMR and 13C NMR spectra of compound 20 |
149 |
Figure 27 |
The Mass and IR spectra of compound 20 |
150 |
Figure 28 |
The 1H NMR and 13C NMR spectra of compound 39 |
151 |
Figure 29 |
The Mass and IR spectra of compound 39 |
152 |
Figure 30 |
The 1H NMR and 13C NMR spectra of compound 40 |
153 |
Figure 31 |
The Mass and IR spectra of compound 40 |
154 |
Figure 32 |
The 1H NMR and 13C-NMR spectra of compound 41 |
154 |
Figure 33 |
The Mass and IR spectra of compound 41 |
155 |
Figure 34 |
The 1H NMR and 13C NMR spectra of compound 42 |
157 |
Figure 35 |
The Mass and IR spectra of compound 42 |
158 |
Figure 36 |
The 1H NMR and 13C NMR spectra of compound 43 |
159 |
Figure 37 |
The Mass and IR spectra of compound 43 |
160 |
Figure 38 |
The 1H NMR and 13C NMR spectra of compound 21 |
161 |
Figure 39 |
The Mass and IR spectra of compound 21 |
162 |
Figure 40 |
The 1H NMR and 13C NMR spectra of compound 5 |
163 |
Figure 41 |
The Mass and IR spectra of compound 5 |
164 |
Figure 42 |
The 1H NMR and 13C NMR spectra of compound 22 |
165 |
Figure 43 |
The Mass and IR spectra of compound 22 |
166 |
Figure 44 |
The 1H NMR and 13C NMR spectra of compound 23 |
167 |
Figure 45 |
The Mass and IR spectra of compound 23 |
168 |
Figure 46 |
The 1H NMR and 13C NMR spectra of compound 24 |
169 |
Figure 47 |
The Mass and IR spectra of compound 24 |
170 |
Figure 48 |
The 1H NMR and 13C NMR spectra of compound 25 |
171 |
Figure 49 |
The Mass and IR spectra of compound 25 |
172 |
Figure 50 |
The 1H NMR and 13C NMR spectra of compound 26 |
173 |
Figure 51 |
The 1H NMR and 13C NMR spectra of compound 27 |
174 |
Figure 52 |
The Mass and IR spectra of compound 27 |
175 |
Figure 53 |
The 1H NMR and 13C NMR spectra of compound 28 |
176 |
Figure 54 |
The Mass and IR spectra of compound 28 |
177 |
Figure 55 |
The 1H NMR and 13C NMR spectra of compound 29 |
178 |
Figure 56 |
The Mass and IR spectra of compound 29 |
179 |
Figure 57 |
The 1H NMR and 13C NMR spectra of compound 30 |
180 |
Figure 58 |
The Mass and IR spectra of compound 30 |
181 |
Figure 59 |
The 1H NMR and 13C NMR spectra of compound 31 |
182 |
Figure 60 |
The Mass and IR spectra of compound 31 |
183 |
Figure 61 |
The 1H-NMR and IR spectra of compound 32 |
184 |
Figure 62 |
The Mass and IR spectra of compound 32 |
185 |
Figure 63 |
The 1H NMR and 13C NMR spectra of compound 33 |
186 |
Figure 64 |
The 1H NMR and 13C NMR spectra of compound 34 |
187 |
Figure 65 |
The 1H NMR and IR spectra of compound 35 |
188 |
Figure 66 |
The 1H NMR and 13C NMR spectra of compound 44 |
189 |
Figure 67 |
The Mass and IR spectra of compound 44 |
190 |
Figure 68 |
The 1H NMR and 13C NMR spectra of compound 45 |
191 |
Figure 69 |
The Mass and IR spectra of compound 45 |
192 |
Figure 70 |
The 1H NMR and 13C NMR spectra of compound 46 |
193 |
Figure 71 |
The Mass and IR spectra of compound 46 |
194 |
Figure 72 |
The 1H NMR and 13C NMR spectra of compound 47 |
195 |
Figure 73 |
The Mass and IR spectra of compound 47 |
196 |
Figure 74 |
The 1H NMR and 13C NMR spectra of compound 48 |
197 |
Figure 75 |
The Mass and IR spectra of compound 48 |
198 |
Figure 76 |
The 1H NMR and 13C NMR spectra of compound 49 |
199 |
Figure 77 |
The Mass and IR spectra of compound 49 |
200 |
Figure 78 |
The 13C NMR spectra of compound 50 |
201 |
Figure 79 |
The Mass and IR spectra of compound 50 |
202 |
Figure 80 |
The 1H NMR and 13C NMR spectra of compound 51 |
203 |
Figure 81 |
The Mass and IR spectra of compound 51 |
204 |
Figure 82 |
The 1H NMR and 13C NMR spectra of compound 52 |
205 |
Figure 83 |
The Mass and IR spectra of compound 52 |
206 |
Figure 84 |
The 1H NMR spectra of compound 53 |
207 |
Figure 85 |
The Mass and IR spectra of compound 53 |
208 |
Figure 87 |
The Mass and IR spectra of compound 54 |
210 |
List of Tables
Table No. |
Content |
Page |
Table 3.1 |
Optimization of the temperature, different solvent and amount of catalyst for the synthesis of 2-(4-methylphenyl)-1H-benzimidazole. |
85 |
Table 3.2 |
Effect of the catalyst and temperature on the model reaction |
90 |
Table 3.3 |
Optimization of the amount of catalyst and different solvents for the synthesis of 4-(1H-benzimidazol-2-yl)phenol |
90 |
Table 3.4 |
Synthesis of arylbenzimidazoles using 1,2-phenylendiamine and aromatic aldehydes in the presence of the catalyst 5 |
92 |
Table 3.5 |
Catalyst recyclability studies in ethanol at 50°C |
94 |
Table 3.6 |
The condensation reaction of 2-aminothiaphenol (1.0 mmol) with benzaldehyde (1.0 mmol) in ethanol at room temperature |
98 |
Table 3.7 |
Optimization of the amount of catalyst and different solvents for the synthesis of 2-phenylbenzothiazole |
98 |
Table 3.8 |
Catalyst recyclability studies in ethanol at room temperature |
99 |
Table 3.9 |
Selective synthesis of benzothiazole from various aromatic aldehydes (1 mmol) and 2-aminothiaphenol (1 mmol) inThe presence of 0.05g of the catalyst 5 in ethanol at room temperature |
100 |
Table 3.10 |
Effect of the temperature on the model reaction |
110 |
Table 3.11 |
Condensation reaction of 1,2-phenylendiamine with benzaldehyde in the presence of Fe3O4-MWCNTs as catalyst at room temperature in different solvents. |
110 |
Table 3.12 |
Synthesis of 2-arylbenzimidazoles using 1,2-phenylendiamine and aromatic aldehydes in the presence of Fe3O4-MWCNTs as catalyst |
111 |
Table 3.13 |
Condensation reaction of 2-aminothiophenol with benzaldehyde in the presence of Fe3O4-MWCNTs as catalyst at room temperature |
115 |
Table 3.14 |
Synthesis of 2-arylbenzothiazoles using 2-aminothiaphenol and aromatic aldehydes in the presence of Fe3O4-MWCNTs as catalyst |
116 |
Table3.15 |
Optimization of model reaction |
119 |
Table 3.16 |
Synthesis of 2-arylbenzoxazole using 2-aminophenol and aromatic aldehydes in the presence of Fe3O4-MWCNTs as catalyst |
120 |
