Microwave-assisted synthesis of 3′-indolyl substituted 4H-chromenes catalyzed by DMAP and their antimicrobial activity

Abstract

A new series of indole-based chromene derivatives 4a-4p has been synthesized by one pot cyclocondensation reaction of 2-phenyl-1H-indole-3-carbaldehyde 1a-1h; malononitrile 2; and 1,3-cyclohexanedione/dimedone 3a/b under microwave irradiation catalyzed by an organocatalyst 4-(N,N-dimethylamino) pyridine. Easy experimental procedure, high yield, selectivity, and shorter reaction time are the imperative features of this method. All the compounds were screened against a representative panel of bacteria and fungi. Some of the compounds are found to be equipotent or more potent than that of standard drugs as evident from SAR study.

Efficient tandem synthesis of a variety of pyran-annulated heterocycles, 3,4-disubstituted isoxazol-5(4H)-ones, and α,β-unsaturated nitriles catalyzed by potassium hydrogen phthalate in water

“…It was found that the rate of reaction of ethyl cyanoacetate (3b) with cyclic 1,3-dicarbonyl compounds (10 and 11) was slower than that of malononitrile (3a), possibly because of the lower reactivity of the cyanoacetates. When ethyl acetoacetate (14) was used as enolizable substrate, the reaction proceeded efficiently, and ethyl 6-amino-5-cyano-2-methyl-4-aryl-4H-pyran-3-carboxylate derivatives (15a-g) were formed in high yields (Table 5, entries 24-30).…”

“…Over the past few years, both these six-membered oxygen-containing heterocycles and their derivatives have attracted much attention, owing to their wide range of biological activity, for example spasmolytic, diuretic, anticoagulant, antianaphylactic [13], antimicrobial [14], antifungal [15], antibacterial [16], antioxidant [17], antileishmanial [18], antitumor [19], local anesthetic [20], antihistaminic [21], and antiallergenic [22] activity and because of their use for treatment of Alzheimer's disease [23] and schizophrenia [24]. Moreover, several chromenes are widely used as pigments [25], cosmetics [26], and laser dyes [27].…”

Lipase-Catalyzed Synthesis of Indolyl 4H-Chromenes via a Multicomponent Reaction in Ionic Liquid

“…The substructure of indole is a key structural motif in a variety of bioactive compounds [8,9]. Therefore, indoyl 4H-chromene has the combined properties of both indole and chromene moieties that provide new promising biological activities [10,11]. Many methods have been presented for the synthesis of these derivatives and various catalysts have been used, such as ZnO nanoparticle, polystyrene-supported p-toluenesulfonic acid, 4-dimethylaminopyridine (DMAP), β-cyclodextrin, oleic acid, 1,4-diazabicyclo[2.2.2]octane (DABCO), microbial cyclosophoraose, etc.…”

Síntese de adutos de Knoevenagel para a obtenção de compostos tetrazólicos, produtos de acoplamento de Suzuki-Miyaura e cromenos por radiação micro-ondas e para a bio-hidrogenação pelo fungo marinho <i>Penicillium citrinum</i>

“…Muitos estudos na literatura empregaram a radiação micro-ondas em diferentes metodologias e estratégias sintéticas e comprovaram a eficiência que apresenta em comparação com os métodos convencionais [24][25][26][27][28][29][30][31][32][33][34][35][36][37][38][39][40][41].…”

“…Guillot et al [35] Kwon et al [36] Bourahla et al [37] Lingham et al [38] Trilleras et al [39] Kumar et al [40] Fozooni et al [41] _____________________________________________________________________________ …”