Microwave-assisted synthesis of novel 5-substituted benzylidene amino-2-butyl benzofuran-3-yl-4-methoxyphenyl methanones as antileishmanial and antioxidant agents

Microwave-Assisted Semisynthesis and Leishmanicidal Activity of Some Phenolic Constituents from Lichens

“…Galbinic acid (5): This compound was isolated from U. cornuta [22]. From 50 g of dry lichen was macerated with methanol (1.2 L) for 24 h. The crude extract was submitted to flash chromatography and then CC using DCM/MeOH mixtures to yield compound 5 (400 mg): 1 H-NMR (DMSO-d 6 , 300 MHz) δ (ppm); 2.47 (3H, s, CH 3 -8), 5.18 (2H, s, CH 2 -9 ), 10.45(1H, s, H-9), 6.89 (1H, s, H-5), 6.82 (1H, s, H-8 ), 8.34 (1H, s, OH-8 ), 12.06 (1H, s, OH-2 ), 1.99 (3H, s, CH3-O) [9]. 13 .…”

“…Additionally, this technique is regarded as an ecofriendly source of energy in chemical synthesis, with better yields and higher purities when compared with traditional processes [5]. This approach has been employed to obtain new antileishmanial compounds such as natural-product-inspired functionalized spiro[indoline-3,2 -pyrrolidin]-2-one/spiro[indoline-3,3 -pyrrolizin]-2-one derivatives [6], γ-butyrolactones derivatives [7], methylene isoindolinone compounds [8], and 5-substituted benzylidene amino-2-butyl benzofuran-3-yl-4-methoxyphenyl methanones [9]. Keeping this in mind, we focused our interest on the condensation of amines with ketones to form imines, a reaction that has proven to be feasible under microwave conditions with promising results [10].…”