Synthesis, spectral analysis, and in vitro microbiological evaluation of ethyl 7,9-diaryl-1, 4-diazaspiro[4.5]dec-9-ene-6- carboxylates as a new class of antibacterial and antifungal agents

Abstract

Keywords: ethyl 7,9-diaryl-1,4-diazaspiro[4.5]dec-9-ene-6-carboxylates, ethylenediamine, p-toluenesulfonic acid, antibacterial activity, antifungal activity.Heterocycles form by far the largest of the classical divisions of organic chemistry and are of immense importance biologically and industrially. The majority of pharmaceuticals and biologically active agrochemicals are heterocyclic, while countless additives and modifiers used in industrial applications, including cosmetics, reprography, information storage, and plastics, are also heterocyclic in nature. The development of simple, efficient, and environmentally benign chemical processes for widely used organic compounds from readily available reagents is one of the major challenges for chemists in organic synthesis.Imidazoline is a nitrogen-containing heterocycle derived from imidazole. The ring contains an imine bond, and the carbon atoms at the positions 4 and 5 are singly rather than doubly bonded as in the case of imidazole. The importance of the imidazoline unit rests on its presence in many biologically active compounds [1,2]. Imidazoline units are also used in organic synthesis as synthetic intermediates [3,4], chiral auxiliaries [5], chiral catalysts [6], and ligands for asymmetric catalysis [7]. Like imidazole, imidazoline-based compounds have been used as N-heterocyclic carbene ligands [8] with various transition metals, for example, in the commercially available second generation Grubbs' catalyst.A good number of bioactive imidazoline derivatives bear a substituent (aryl or alkyl group) on the carbon atom between the nitrogen centers.

An efficient synthesis of anti-microbial 1,2,4-triazole-3-thiones promoted by acidic ionic liquid

“…Furthermore, most of the present antifungal drugs are not effective against invasive Aspergillosis and the only drug of choice in such patients is the injectable amphotericin B. Some examples of bioactive bicyclics 1,2,4-triazole-based anxiolytic drugs are estazolam, alprazolam, 5-HT1 agonist triptan drug, rizatriptan and antimicrobial drugs such as spiropiperidinyl-1,2,4-triazolidine-3-thiones [21][22][23][24][25][26][27]. Due to these multifarious applications, there is a need for a proficient and green approach to synthesize bioactive spirotriazoles by using readily available starting materials.…”

Synthesis and Antimicrobial Activity of Novel Hydrazone and 1,2,4-Triazole-3-thione Derivatives

“…The 1,2,4-triazole-3-thione fragment occurs in the structure of many natural and biologically active compounds [16,17], for example, in bicyclic anxiolytic drugs, estazolam, alprazolam (Scheme 1), in the triptan 5-HT1 agonist (rizatriptan) and in antimicrobial agents based on spiropiperidinyl-1,2,4-triazolidine-3-thione [18][19][20][21][22]. For the synthesis of heterocyclic compounds with antimicrobial activity with a 1,2,4-triazole-3-thione moiety, the reaction of ketones with thiosemicarbazide is used [23][24][25][26][27].…”

“…Scheme 1 shows examples of biologically active hydrazones and 1,2,4-triazole-3-thione derivatives, which have antimicrobial (1) [4], antiprotozoal (2) [8], antimicrobial (3) [21], and anti-inflammatory activity (4) [6]. Hydrazone 5 inhibits the phosphodiesterase 10A enzyme responsible for neurological and psychological disorders (schizophrenia) [14].…”