Organic Communications

Year: 2023 Volume: 16 Issue:4 October-December

Original Article

1) Water extract of onion: chemoselective synthesis of 2-substituted benzimidazole derivatives

Org. Commun. (2023) 16:4 ; 175 - 186
by Ayyavu Boomathi , Kaliyan Prabakaran , Govindaraj Mahalakshmi , Selvaraj Loganathan , Eswaran Rajendran and Muthu Seenivasa Perumal

A facile, efficient, green synthetic route was developed for the selective synthesis of 2-substituted benzimidazole derivatives via the reaction of 1,2-diamines with aromatic, aliphatic and hetero aromatic nitroalkenes in the presence of an onion extract as a green catalyst. In this reaction, fifteen 2-substituted benzimidazole derivatives were obtained in good to excellent yields (80-95%). The method presented here offers several benefits, including minimal energy usage, cheap, nontoxic catalyst, simple workup procedure and without column purification. The usage of onion extract creates this approach is environmentally friendly and makes a significant addition to the currently available techniques for the creation of 2-substituted benzimidazoles.  Further, the scope and constraints were also investigated, and a conceivable reaction mechanism was put forth.

DOI
http://doi.org/10.25135/acg.oc.157.2305.2790
Keywords
Chemoselectivity water extract of onion green catalyst 2-substituted benzimidazoles 1,2-Diamines
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© 2023 ACG Publications. All rights reserved.
Original Article

2) An efficient synthesis of quinoxaline derivatives using HCTU as catalyst in DMF

Org. Commun. (2023) 16:4 ; 187 - 196
by Nitin A. Sasane , Bhushan B. Popatkar and Gangadhar A. Meshram

We have successfully developed a novel and efficient method for the synthesis of quinoxaline and its derivatives. This method involves the reaction between various 1,2-diamines and substituted phenacyl bromides in the presence of a catalytic amount of O-(1H-6-Chlorobenzotriazole-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (HCTU) in dimethylformamide (DMF) as the solvent. This protocol offers several advantages, including mild reaction condition, short reaction time and moderate to high yield of the desired product(s).

DOI
http://doi.org/10.25135/acg.oc.160.2308.2876
Keywords
Quinoxalines HCTU 1,2-Diamines phenacyl bromides
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© 2023 ACG Publications. All rights reserved.
Communication

3) Synthesis and bioactivity of 1-substituted tetrahydroisoquinolines derived from phenolic aldehydes

Org. Commun. (2023) 16:4 ; 197 - 203
by Muamer Dizdar , Milka Maksimović , Anela Topčagić , Monia Avdić and Danijela Vidic

Phenolic aldehydes and their derivatives found in nature are well-known for their potential biological activity. In this study, four 1-substituted 1,2,3,4-tetrahydroisoquinolines (THIQs) derived from phenolic aldehydes were synthesized by phosphate buffer mediated Pictet-Spengler reaction. All derivatives were chemically and structurally characterized by elemental CHN analysis and spectroscopic methods (IR, HR-ESI-MS, 1H- and 13C-NMR). 1-Substituted THIQs derived from 3,4-dihydroxybenzaldehyde and 4-hydroxy-3-methoxybenzaldehyde were described for the first time. In order to cover the diversity of the mechanistic approach, but also to establish the relationship between structure and activity, antioxidant activity was examined by five different in vitro methods, namely: neutralization and reduction of stable free radicals 2,2-diphenyl-1-picrylhydrazyl and radical cation derived from [(2,2´-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)], ferric reducing antioxidant power, oxygen radical absorbance capacity, and ability to chelate Fe(II) ions. In vitro inhibition of acetylcholinesterase (AChE) was examined by the Ellman's colorimetric method, while computer-simulated docking was used to reveal the preferred binding site and major interaction between AChE and THIQs. Antibacterial testing was examined using the agar well method and results were presented in the form of zones of inhibition (mm).

DOI
http://doi.org/10.25135/acg.oc.159.2310.2920
Keywords
Synthesis bioactivity 1-Substituted tetrahydroisoquinolines phenolic aldehydes
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Communication

4) Synthesis and antimicrobial activities of unsymmetrical thioditetrazoles and their precursor thiotetrazoles

Org. Commun. (2023) 16:4 ; 204 - 211
by Özge Çağlar Teknikel , Hatice Öğütcü , Doğukan Doyduk and Ali Dişli

In this study, a synthetic route to access unsymmetrical ditetrazoles was developed. By using this method, the first examples of unsymmetrical thioditetrazole compounds were synthesized. In vitro, antibacterial efficacy studies were carried out for all the thioditetrazoles and their precursor thiotetrazoles against ten bacteria. The synthesized compounds showed a strong antibacterial effect against pathogenic Gram-negative bacteria, especially Escherichia coli, Salmonella typhi and Pseudomonas aeruginosa (up to 21 mm).

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DOI
http://doi.org/10.25135/acg.oc.158.2309.2893
Keywords
Tetrazole thiotetrazole dithiotetrazole antibacterial activity antifungal activity
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© 2023 ACG Publications. All rights reserved.