Synthesis and antibacterial activity of some new fused chromenes

Abstract

A new class of pyrano [3,4-c] [4,3-c]pyrazole has been prepared from 3-benzoyl-2H-chromen-2-one 1. Most of the chromene derivatives showed moderate to high antibacterial activity as compared to the starting material 1.

Synthetic Routes to Coumarin(Benzopyrone)-Fused Five-Membered Aromatic Heterocycles Built on the α-Pyrone Moiety. Part II: Five-Membered Aromatic Rings with Multi Heteroatoms

“…Additionally, 3-coumarinyl alkyl ketones, such as 4-hydroxy-3-acetylcoumarin ( 17a ) [ 32 ], and 3-coumarinyl phenyl ketone ( 17b ) [ 12 ] were the starting materials in the preparation of chromeno[4,3- c ]pyrazol-4(2 H )-ones 18 and 19 by the base-catalyzed reaction with hydrazine hydrate ( Scheme 6 ).…”

“…Certain derivatives of 3,4-heterocycle-fused coumarins play an important role in medicinal chemistry and have been extensively used as versatile building blocks in organic synthesis [ 2 , 3 , 5 , 6 , 7 ]. Many examples of biologically active coumarins containing 3,4-heterocycles-fused were cited in the literature [ 2 , 3 , 8 ] including antimicrobial [ 9 , 10 , 11 , 12 ], antiviral [ 13 , 14 ], anticancer [ 15 , 16 , 17 ], antioxidant [ 18 , 19 ], and anti-inflammatory [ 20 , 21 ] activities.…”

[DBN][HSO4]-Promoted facile and green synthesis of 2-Amino-4H-pyrans derivatives under microwave irradiation

“…2-Amino-4H-pyrans derivatives have been investigated for a wide range of pharmacologic indications such as potent bioactive compounds found in dyes, cosmetics, pigments and also utilized in agrochemicals because of their biodegradable properties. [1][2][3] Many of the natural product isolated resemble the structure of the poly functionalized 4H pyrans, [4][5] represented several biological activities, 6 such as antibacterial, [7][8][9][10][11] anti-allergic, 2 antitumor, 12 calcium channel antagonists, 13 anti-HIV, 14 antitubercular, 15 antimalarial 16 and anticancer, 17 The structures of representative compounds are shown in Fig. 1.…”

4-Amino-2-(p-tolyl)-7H-chromeno[5,6-d]oxazol-7-one

“…Aminocoumarins are valuable building blocks for the synthesis of fused pyridocoumarins presenting significant biological activities such as antibacterial [22], antifungal [23], antimalarial [24], antioxidant [25] and wound-healing [26]. Pyridocoumarins are prepared from aminocoumarins through the one-pot Povarov reactions with aromatic aldehydes and cyclic enol ethers [27], the reactions with vinyl ketones [28], or under Vilsmeier conditions [29] or with phenylacetylene and benzaldehydes under catalysis by I 2 [30] or by other Lewis acids [25,31].…”

“…The need for the synthesis of new compounds, to probe novel biological activity containing a heterocyclic ring fused to the pyridocoumarin moiety, led us to the synthesis of amino-substituted fused oxazolocoumarins. In continuation of our interest on fused oxazolocoumarin [8,22] and pyridocoumarin [25,33,34] derivatives, we would like to report here the synthesis of novel amine 7, through a selective reduction procedure, and the biological evaluation of the products. The reactions studied and the synthesized products are depicted in Scheme 1.…”