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EtO OEt NH 2CN NH 2 AcOH EtO OEt Scheme-1.10.2 Lawson’s synthesis. H N NH NH 2 HCl H 2O N H N NH 2.HCl Kruetzberger found that condensation of 1,2-hydrazinedicarboxamidine with benzoin derivatives in alkali media will yield symmetrically substituted azoimidazoles after spontaneous oxidation of the bis-imidazolhydrazine (Scheme-1.10.3). 86 Reductive cleavage of the azo group by hydrogenolysis gives two mole equivalents of the 2aminoimidazole. This methodology is useful but limited to the preparation of 4,5diaryl substituted 2-aminoimidazoles. H 2N HN HN NH NH NH 2 Ar O OH Ar NaOH Scheme-1.10.3 Kruetzberger’s condensation. Ar In 1966, Lancini and Lazzari successfully expanded Lawson’s strategy to include α - aminoketones, including the use of N-alkylamines (Scheme-1.10.4). 87-88 They were the first to observe the strict pH dependence of this condensation. At very low pH the cyanamide is quickly converted to urea. At high pH, dimerization of the aminoketone to the piperazine competes with cyanamide condensation. Having established the optimum pH of the reaction to be ~4.5, these conditions are now routinely adopted. In 1925 Pyman and Burtles had reported the reaction of α-bromoacetone and guanidine to give a mixture of uncharacterizable compounds, leading them to abandon this approach and develop their diazonium coupling described below. 89 Seventy years later, Weber discovered that N-acetylguanidine smoothly undergoes displacement and condensation with α -haloketones and aldehydes. 90 O H N NH 2CN pH = 4.5 N N N NH Ar HN N N Ar N Ar NH 2 H 2 Pd/C Scheme-1.10.4 Lancini and Lazzari’s expanded strategy Ph Ar HN Ar N NH 2
R 1 O X R 2 NH 2 H 2N NAc R 1 HN R 2 N NHAc NH 2NH 2 OR H 2SO 4 Scheme-1.10.5 Weber’s condensation with N-acetylguanidine. In the late 1970’s Nishimura reported the condensation of substituted α-diketones with guanidine to yield a variety of useful products (Scheme-1.10.6). 91 This report illuminates the variety of chemistry that is possible around this heterocyclic core. Treatment of a diketone with guanidine in dioxane and methanol yields the substituted bicyclic bis-guanidine . Alternatively, aprotic reaction conditions can selectively deliver the 2-aminoimidizo-4-ol. This intermediate can undergo a base catalyzed pinacol-type rearrangement to form the 2-aminoimidizo-4-one. This same intermediate can give rise to the 4,5-diol upon exposure to aqueous hydrochloric acid. A similar hydration reaction with anhydrous HCl affords the di-methoxylated derivative. Hydrogenolysis of 2-aminoimidizo-4-ol cleanly gives the 4,5-dialkyl-2aminoimidazole. These laboratory transformations foreshadow potential biosynthetic relationships between the 2-aminoimidazole natural products isolated from marine sponges. R 2 O R1 R2 NH 2 HN N HN N NH 2 N N H R 1 NaOH MeOH NH 2 dioxane MeOH R1 R2 HO HO conc.HCl N N H R 1 R 2 NH 2 Scheme-1.10.6 Nishimura’s diketone condensation O O H 2N HN MeO R 1 NH 2 MeOH HCl N NH 2 R 1 R 2 R 1 R 1 HN OH N R2 N R N MeO H 2 H N N R 2 N NH 2 NH 2 H2/Pd-C MeOH NH 2
Page 1 and 2: Saurashtra University Re - Accredit
Page 3: JANUARY-2011 Statement under O. Ph.
Page 7 and 8: Acknowledgment This thesis arose in
Page 9 and 10: since I was a child. My Mother Hans
Page 11 and 12: CHAPTER - 2 Microwave Assisted Synt
Page 13 and 14: 5.5 Results and discussion 156 5.6
Page 15 and 16: Ms Mesyl MW Microwave NBS N-bromosu
Page 17 and 18: 1. Microwave Assisted Organic Synth
Page 19 and 20: 1.4 Heating Mechanism In microwave
Page 21 and 22: 1.5. Effects of solvents Every solv
Page 23 and 24: 1.7 Application of microwave in org
Page 25 and 26: aromatic amines, Lancini’s group
Page 27 and 28: 1.9 2-Aminoimidazole Alkaloids The
Page 29 and 30: Recently group of Erik 83 described
Page 31: 1.10 Methods for the preparation of
Page 35 and 36: this manifold, was reported in 1925
Page 37 and 38: Another route to 4(5)-acyl-2-amino-
Page 39 and 40: this series of compounds against th
Page 41 and 42: documented. Extra care is needed be
Page 43 and 44: Very recently the research group of
Page 45 and 46: OH a,b O N H2N N Boc N 3 H N R N N
Page 47 and 48: 1.12.2 Biofilm Growth Cycle 1) Plan
Page 49 and 50: can survive both the onslaught of a
Page 51 and 52: [26] Leadbeater, N. E. (2004) Chemi
Page 53 and 54: [86] Kreutzberger, A. (1962) J. Org
Page 55 and 56: Microwave Assisted Synthesis & Stru
Page 57 and 58: 2.1 Introduction As described in ch
Page 59 and 60: 2.3 Proposed Mechanism: Regarding t
Page 61 and 62: No. 12 60 120 traces 84 a All react
Page 63 and 64: the development of biofilm related
Page 65 and 66: In first instance, a series of 2-hy
Page 67 and 68: Br N N N R 1 OH Br N N N R 1 OH Fig
Page 69 and 70: do have a very strong effect agains
Page 71 and 72: 2.6 Conclusion In the present study
Page 73 and 74: 2.8 Biological assays 2.8.1 Static
Page 75 and 76: 2.9 Experimental protocol: 2.9.1 Ge
Page 77 and 78: temperature of 80 °C and a maximum
Page 79 and 80: 29.5,29.4, 29.2, 27.0, 22.6, 14.1.
Page 81 and 82: Yield: 78 %. 1 H NMR (300 MHz, CDCl
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N Br N N C 14H 29 OH Yield: 72 %. 1
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(75.5 MHz, CDCl3): δ = 167.7, 154.
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N Br N N C 14H 29 OH Cl Yield: 90 %
Page 89 and 90:
2-(3,4-Dichlorophenyl)-2-hydroxy-1-
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N Br N N C 8H 17 OH NO 2 Yield: 49
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C3H7 HN N N H Cl Cl Yield : 70 %. 1
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(s, 1H), 3.16 (s, 3H), 1.80 (m, 2H)
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5-(4’-Nitrobiphenyl-4-yl)-N-octyl
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2.11 Representative NMR spectra 2.1
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2.11.3 10.4329 0.7429 151.5720 10.0
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[21] Matz C, McDougald D, Moreno A.
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Chapter-3 Structure Activity Relati
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imidazoles, where the addition of a
Page 109 and 110:
3.4 Result and Discussion It was fo
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No. H 2N Compound Code N N C8H17 R1
Page 113 and 114:
medium used in the set-up to monito
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H 2N N N N H2N N R R Figure-1 Effec
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3.5.3 Cyclo-alkyl 2-aminoimidazoles
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3.6. Conclusion In the present stud
Page 121 and 122:
3.8. Experimental protocols 3.8.1 G
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122.6, 54.6, 33.3(×2), 27.3 (×2),
Page 125 and 126:
Yield: 52 %. 1 H NMR (300 MHz, CDCl
Page 127 and 128:
5-(4-Chlorophenyl)-1-cyclooctyl-1H-
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Yield: 50 %. Mp: 76-78 ° C. 1 H NM
Page 131 and 132:
5-(4-Chlorophenyl)-1-cyclobutyl-1H-
Page 133 and 134:
Yield: 66%. 1 H NMR (300 MHz, CDCl3
Page 135 and 136:
3.10 Representative NMR spectra 3.1
Page 137 and 138:
3.11 References [1] (a) Alvi K. A,
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Copper Catalyzed Microwave Assisted
Page 141 and 142:
4.1 Introduction There are only a f
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(Table-1, No- 6). Next reaction tem
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No. Product, Yield b (%) No. Produc
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4.4 Possible Mechanism Regarding th
Page 149 and 150:
4.7 Experimental protocols 4.7.1 Ge
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Yield: 69 %. 1 H NMR (300 MHz, CDCl
Page 153 and 154:
1-(3-Azidopropyl)-2-(3,4-dichloroph
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Yield: 84 %. 1 H NMR (300 MHz, DMSO
Page 157 and 158:
Page 159 and 160:
Page 161 and 162:
1H), 1.66 (m, 6H), 1.70 (m, 2H). 13
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5.48 Hz, 2H), 3.59 (m, 2H), 3.16 (d
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4.10 References [1] For a general r
Page 167 and 168:
Crystal and Molecular Structure Ana
Page 169 and 170:
5.1 Introduction The membrane efflu
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oscillation range of 5˚ and proces
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C12-C13 1.372(4) C32-C37 1.390(3) C
Page 175 and 176:
Fig.-3: Packing of the molecules wh
Page 177 and 178:
1 H NMR (400 MHz CDCl3): δ = 7.57-
Page 179 and 180:
5.9.2 13 C spectra of bs-DP-7
Page 181 and 182:
SUMMARY The work represented in the
Page 183 and 184:
CONFERENCES/SEMINARS/WORKSHOPS ATTE
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PUBLICATIONS [1] One-Pot Microwave-
Page 200 and 201:
Scheme 2 Competitive formation of 1
Page 202 and 203:
Table 2 continued 9 10 11 12 N hydr
Page 204:
8. Colson G, Raboult L, Lavelle F,
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