Efficient and Convenient Method for Synthesis of Benzofuran-3-acetic Acids and Naphthafuran-acetic Acids

Abstract

Herein, we report an efficient and convenient method for synthesis of benzofuran-3-acetic acids and naphthafuran-acetic acids 5a-p by the reaction of substituted-4-bromomethylcoumarins with aqueous sodium hydroxide at refluxing temperature. The obtained products are characterized by infrared, 1 H NMR, 13 C NMR, and mass spectral data. Structures 5a and 5e are confirmed by their single x-ray diffraction studies. The advantages of this method are good yields, easy workup, and no chromatographic purifications.

Crystal structure of 2-(5-methoxy-1-benzofuran-3-yl)acetic acid

“…For a related structures and background to benzofurans and their applications, see: Dawood (2013); Khanam & Shamsuzzaman (2015); Radadiya & Shah (2015); Naik et al (2015); Nevagi et al (2015). For the synthesis, see: Basanagouda et al (2015) Table 1 Hydrogen-bond geometry (Å , ). Symmetry codes: (i) Àx; Ày þ 2; Àz þ 2; (ii) x; Ày þ 3 2 ; z þ 1 2 .…”

“…In addition, substituted benzofurans find application such as fluorescent sensors, oxidant, antioxidants and brightening agents. The derivatives of 2,3-dihydrobenzofuranyl-3-acetic acid have been reported to be potent, selective and orally bioavailable G protein-coupled receptor 40 (GPR40) and free fatty acid receptor 1 agonists (FFA1) (Basanagouda et al, 2015). A perspective view of the molecule is shown in Fig.…”

2-(4,6-Dimethyl-1-benzofuran-3-yl)acetic acid

“…Carboxylic acids, such as arylalkanoic acids, exhibit anti-inflammatory, analgesic and antipyretic properties and have been in widespread clinical use for a number of years (Basanagouda et al, 2015). As part of our studies in this area, we now report the crystal structure of the title compound.…”

“…Colourless blocks were obtained by recrystallization from an ethanol and ethyl acetate solvent mixture by slow evaporation (m.p. 442-443 K) (Basanagouda et al, 2015).…”

2-(5-Methyl-1-benzofuran-3-yl)-N-(2-phenylethyl)acetamide

“…5-Methyl-benzofuran-3-acetic acid (10 mmol) (Basanagouda et al, 2015;Uriarte et al, 1995) was refluxed with phenylethylamine (10 mmol) in benzene (30 ml) for 7 h (monitored by TLC). The solvent was removed to obtain a colourless solid, which was crystallized from a mixture of benzene and petroleum ether (1:1).…”