Regioselective reactivity of some 5,7-dimethoxyindoles

Condie, Glenn C.; Channon, Michelle F.; Ivory, Andrew J.; Kumar, Naresh; Black, David StC.

doi:10.1016/j.tet.2005.03.048

Cited by 21 publications

(18 citation statements)

References 17 publications

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“…In our research, Friedel-Crafts acylation of indoles with oxalyl chloride gave 3-substituted products (via the more stable carbocation intermediates with two complete phenyl rings as the resonants) in higher yields. Ether was the most effective solvent, allowing precipitation of the glyoxyloyl chlorides [18]. N-acylation of compound 9a, a very weak secondary amine, afforded corresponding compounds 9f-g, as shown in Scheme 2.…”

Section: Resultsmentioning

confidence: 99%

Synthesis and antitumor activity of novel podophyllotoxin derivatives against multidrug-resistant cancer cells

Guo

Chen

Zuo

et al. 2011

Journal of Asian Natural Products Research

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Section: Resultsmentioning

confidence: 99%

Synthesis and antitumor activity of novel podophyllotoxin derivatives against multidrug-resistant cancer cells

Guo

Chen

Zuo

et al. 2011

Journal of Asian Natural Products Research

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“… 31 , 40 , 41 In some circumstances, the Knoevenagel condensation (step ii, Scheme 2 ) requires highly excessive quantities of the reactant azidoacetate and the catalytic base (e.g., benzaldehyde:azidoacetate:methoxide = 1:10:10 molar ratio) to achieve high yields. 42 We tried different stoichiometries of the reactants in the condensation of 14 with 15 and found when the molar ratio of reactants (benzaldehyde:azidoacetate:methoxide) is 1:3:3, it provided an acceptable yield ranging from 58% to 74% for the products 16a – d . When the molar ratio of reactants used was benzaldehyde:azidoacetate:methoxide = 1:10:10, the yields for 16a and 16b were increased from 59% and 58% to 93% ( 16a ) and 69.6% ( 16b ), respectively.…”

Section: Methodsmentioning

confidence: 99%

Optimization of Chemical Functionalities of Indole-2-carboxamides To Improve Allosteric Parameters for the Cannabinoid Receptor 1 (CB1)

et al. 2014

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5-Chloro-3-ethyl-N-(4-(piperidin-1-yl)phenethyl)-1H-indole-2-carboxamide (1; ORG27569) is a prototypical allosteric modulator for the cannabinoid type 1 receptor (CB1). Here, we reveal key structural requirements of indole-2-carboxamides for allosteric modulation of CB1: a critical chain length at the C3-position, an electron withdrawing group at the C5-position, the length of the linker between the amide bond and the phenyl ring B, and the amino substituent on the phenyl ring B. These significantly impact the binding affinity (KB) and the binding cooperativity (α). A potent CB1 allosteric modulator 5-chloro-N-(4-(dimethylamino)phenethyl)-3-propyl-1H-indole-2-carboxamide (12d) was identified. It exhibited a KB of 259.3 nM with a strikingly high binding α of 24.5. We also identified 5-chloro-N-(4-(dimethylamino)phenethyl)-3-hexyl-1H-indole-2-carboxamide (12f) with a KB of 89.1 nM, which is among the lowest KB values obtained for any allosteric modulator of CB1. These positive allosteric modulators of orthosteric agonist binding nonetheless antagonized the agonist-induced G-protein coupling to the CB1 receptor, yet induced β-arrestin mediated ERK1/2 phosphorylation.

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“…To synthesize the initially required 7‐oxygenated 2,3,4,7‐tetrasubstituted indoles 6a and 6b , we chose known ethyl 7‐alkoxyindole‐2‐carboxylates 7a and 7b 14 as the starting materials (see Scheme ). The treatment of 7a or 7b with α,α‐dichloromethyl methyl ether in the presence of TiCl 4 15 gave 4‐formylindoles 8a and 8b , respectively. The formyl groups of 8a and 8b were subsequently reduced with NaBH 4 to give the hydroxymethyl groups of 9a and 9b , which were treated with chloromethyl methyl ether (MOMCl) in the presence of N , N ‐diisopropylethylamine ( i Pr 2 NEt) to yield MOM ethers 10a and 10b .…”

Section: Resultsmentioning

confidence: 99%

Total Synthesis of the Neuronal Cell‐Protecting Carbazole Alkaloids Carbazomadurin A and (S)‐(+)‐Carbazomadurin B

et al. 2013

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The total syntheses of the neuronal cell‐protecting carbazole alkaloids carbazomadurin A and (S)‐(+)‐carbazomadurin B were achieved. The key step of the synthesis of the polysubstituted carbazole rings included an allene‐mediated electrocyclic reaction of the 6π‐electron system that involved the indole 2,3‐bond. The cleavage of the alkoxy groups of the resulting 3‐ethoxy‐8‐isopropoxycarbazole successfully gave the 3,8‐dihydroxycarbazole, which was converted into the 3,8‐bis(OSEM)‐carbazole (SEM = 2‐trimethylsilylethoxymethyl). A Suzuki–Miyaura cross‐coupling reaction of the 3,8‐bis(OSEM)‐carbazole with the corresponding alkenyl pinacol borates afforded the 1‐alkenylcarbazoles, which were treated with tetra‐n‐butylammonium fluoride (TBAF) followed by reduction with NaBH4 to provide carbazomadurin A and (S)‐(+)‐carbazomadurin B, respectively.

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Regioselective reactivity of some 5,7-dimethoxyindoles

Cited by 21 publications

References 17 publications

Synthesis and antitumor activity of novel podophyllotoxin derivatives against multidrug-resistant cancer cells

Synthesis and antitumor activity of novel podophyllotoxin derivatives against multidrug-resistant cancer cells

Optimization of Chemical Functionalities of Indole-2-carboxamides To Improve Allosteric Parameters for the Cannabinoid Receptor 1 (CB1)

Total Synthesis of the Neuronal Cell‐Protecting Carbazole Alkaloids Carbazomadurin A and (S)‐(+)‐Carbazomadurin B

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