- Catalyst-Free Synthesis of Aryl Diamines via a Three-Step Reaction Process
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The formation of C-N bonds with aryl amines is one of the most widely studied reactions in organic chemistry. Despite this, it is still highly challenging, often requiring expensive, precious metal-based catalysts. Here we report an easy catalyst-free methodology for constructing C-N bonds. The method, which proceeds via the in situ formation of closed ring amidinium ions, allows the preparation of a series of symmetrical and/or unsymmetrical aryl diamines in notably high yields (82-98%) and purity and with a variety of different substituents. The methodology is shown successful for the preparation of aryl diamines having para- and/or meta-substituted carboxyl, nitro, bromo, methoxy, or methyl groups. This green synthetic pathway, which is catalyst free, requires only three steps, and proceeds without the need for purification. Further, it is a new sustainable, economically viable method to achieve an otherwise challenging bond formation.
- Bulut, Safak,Queen, Wendy L.
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p. 3806 - 3818
(2018/04/14)
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- RUBBER COMPOSITION, TIRE, BISPHENYLDIAMINE COMPOUND, AND ANTI-AGING AGENT
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Provided is a rubber composition that has better weather resistance than conventional rubber compositions and can inhibit rubber article surface discoloration. The rubber composition contains at least one rubber component selected from natural rubber and
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Paragraph 0122; 0123; 0130; 0131
(2017/07/14)
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- Synthesis, antitubercular and anticancer activities of p-nitrophenylethyl-enediamine-derived schiff bases
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Background: Schiff bases have been greatly studied in biological field due to their wide range of pharmacological activities, such as antitubercular and antitumour. In the search of novel antitubercular agents, several compounds containing pharmacophoric group of ethambutol have been synthesized and evaluated against mycobacteria species causing tuberculosis. In this work, we investigate whether ethylenediamine, Schiff base as well as nitro group together could contribute to the formation of novel molecules with dual biological activities: antitubercular and anticancer. Methods: A series of Schiff bases (3-12) derived from p-nitrophenylethylenediamine (1) as well as N1,N2-bis(4-nitrophenyl)ethane-1,2-diamine (2) were synthetized and assayed for their action against Mycobacterium tuberculosis H37Rv strain and the human tumour cell lines SF-295 (glioblastoma multiforme), HCT-116 (colon adenocarcinoma) and OVCAR-8 (ovarian cancer). Results: Among the compounds that showed antimycobacterial effects, 4 was more active than ethambutol, the antitubercular drug used as positive control. Also, compounds 1, 8, 10 and 12 were able to reduce strongly the viability of the tumour cell lines at 5 gmL-1. Conclusion: According to studies, some modifications on p-nitrophenylethylenediamine (1) were an effective strategy to obtain compounds with antiproliferactive activities. Also, Schiff base 4 proved to be the lead antitubercular compound.
- Amim, Raquel S.,Pessoa, Cláudia,Louren?o, Maria C.S.,De Souza, Marcus V.N.,Lessa, Josane A.
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p. 391 - 397
(2017/06/20)
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- 1,4-Diarylpiperazines and analogs as anti-tubercular agents: Synthesis and biological evaluation
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Despite progress in modern chemotherapy to combat tuberculosis, the causative pathogen Mycobacterium tuberculosis (M.tb.) is far from eradicated. Bacillary resistance to anti-mycobacterial agents, bacillary persistence and human immunodeficiency virus (HIV) co-infection hamper current drug treatment to completely cure the infection, generating a constant demand for novel drug candidates to tackle these problems. A small library of novel heterocyclic compounds was screened in a rapid luminometric in vitro assay against the laboratory M.tb. strain H37Rv. A group of amidines was found to have the highest potency and was further evaluated for acute toxicity against C3A hepatocytes. Next, the most promising compounds were evaluated for activity against a multi-drug resistant clinical isolate. The group of amidines was also tested for their ability to kill intracellular M.tb. residing in mouse J774A.1 macrophages. Finally, we report on a correlation between the structural differences of the compounds and their anti-mycobacterial activity.
- Forge,Cappoen,Laurent,Stanicki,Mayence,Huang,Verschaeve,Huygen,Vanden Eynde
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scheme or table
p. 95 - 101
(2012/04/10)
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