Design and Synthesis of Novel Antimicrobial Acyclic and Heterocyclic Dyes and Their Precursors for Dyeing and/or Textile Finishing Based on 2-N-Acylamino-4,5,6,7-tetrahydro-benzo[b]thiophene Systems

Abstract

A series of novel polyfunctionalized acyclic and heterocyclic dye precursors and their respective azo (hydrazone) counterpart dyes and dye precursors based on conjugate enaminones and/or enaminonitrile moieties were synthesized. The dyes and their precursors are based on 2-cyano-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)-acetamide, 2-ethoxycarbonyl-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)-acetamide or 2-phenylcarbamoyl-N-(3-cyano-4,5,6,7-tetrahydrobenzo[b]thiophen-2-yl)-acetamide systems as precursors. The latter compounds were used to synthesize polyfunctional thiophene-, thiazole-, pyrazole, pyridine-, pyrimidine-, oxazine-, as well as acyclic moieties. The dyes and dye precursors were characterized by elemental analysis and spectral methods. All dyes and their precursors were screened in vitro and evaluated for both their antibacterial and antifungal activities. MIC data of the novel dye systems and their respective precursors showed significant antimicrobial activity against most tested organisms. Some compounds exhibited comparable or even higher efficiency than selected standards. Dyes were applied at 5% depth for disperse dyeing of nylon, acetate and polyester fabrics. Their spectral characteristics and fastness properties were measured and evaluated.

Synthesis of Thiazolinone, Aminopyrazole, Pyrazolopyrimidine, and Pyrazolotriazine Derivatives Starting from 1‐Naphthyl‐2‐Cyanoacetamide

“…Now, we have extended our synthetic program to the synthesis of otherwise inaccessible heterocyclic ring systems utilizing 1-naphthyl-2-cyanoacetamide (1) and PhNCS as keys starting materials. It is known that a great variety of reactants bearing the N-C-S fragment undergo cyclization on reaction with α-halocarbonyl compounds to afford thiazole, 2,3-dihydro-thiazole and thiazolidines moieties [23] which have been shown to exhibit local antitumor and antioxidant [24], antimicrobial [25], and antitumor activity [26]. Here, we describe a generally applicable extension of this synthetic approach; the base prompted reaction of the acidic methylene compound (1) with phenyl isothiocyanate in dry dimethylformamide at room temperature yields the non-isolable intermediate (3).…”

“…Moreover, the mass spectrum showed molecular ion peak at m/z = 384.95 (M + ) corresponding to its molecular formula C 21 H 15 N 5 OS. A proposed reaction sequence involved an initial nucleophilic addition of the exocyclic amino group in aminopyrazole (11) to phenyl isothiocyanate giving (23) 5-Amino-N-(naphthalen-1-yl)-3-(phenylamino)-1H-pyrazole-4-carboxamide (11) has been diazotized in acetic acid with HCl and sodium nitrite at 0-5°C to yield non isolable pyrazoldiazonium salts (25). The attempted coupling with active methylene reagents resulted in direct formation of pyrazolo [3,4- (26) via cyclocondensation reaction which took place in situ under coupling reaction conditions.…”

Synthesis of Novel Heterocyclic Compounds Incorporate 4,5,6,7-Tetrahydrobenzo[<i>b</i>]thiophene Together with Their Cytotoxic Evaluations

“…18,19) It has been reported that multi-component reactions (MCRs) can combine three or more components together in a single reaction vessel and produce final products with a minimum of synthetic time and effort 20) because they are no need to separate any reaction intermediate. 21) Such MCRs often result in high atomeconomy and high selectivity products.…”

Cyanoacetamide Intermediate in Heterocyclic Synthesis: Synthesis and Biological Evaluation of Hitherto New Dioxoisoindoline Heterocyclic Derivatives

“…The literature that covers the chemistry of cyanoacetamides has been limited. Derivatives of 2‐cyano‐ N ‐acetamide are tremendously important precursors in the synthesis of heterocyclic systems . The most approximate preparation of these compounds has been explained elsewhere .…”