An Efficient One‐Pot Synthesis of Substituted 1H‐Naphtho[2,1‐b]pyrans and 4H‐1‐Benzopyrans (=Chromenes) under Solvent‐Free Microwave‐Irradiation Conditions

Abstract

A facile heterogeneous synthesis of 3‐amino‐1‐aryl‐1H‐naphtho[2,1‐b]pyran and 2‐amino‐4‐aryl‐4H‐1‐benzopyran derivatives 3 and 5, respectively, was carried out efficiently by one‐pot three‐component coupling of an aromatic aldehyde 1, an active methylene compound 2, and naphthalen‐2‐ol or a phenol 4 in the presence of 5‐Å molecular sieves under solvent‐free microwave‐irradiation conditions (Scheme 1 and 2, Tables 1 and 2). The catalyst was recovered and recycled (Table 3).

3-Amino-1-(4-fluorophenyl)-8-methoxy-1H-benzo[f]chromene-2-carbonitrile

“…This implies that the furan ring is approximately planar as borne out by the observation that the methine-C11 atom lies only 0.132 2 it is attached as seen in the value of the C14-O2-C6-C5 torsion angle of 0.5 (3)°. The structure described here resembles very closely those of the 4-bromo (Wang et al, 2008) and 2-CF 3 (Shekhar et al, 2012) Table 1.…”

“…For background to the chemistry and biological activity of 4H-pyran derivatives, see: El-Agrody et al (2011); Sabry et al (2011). For related structures, see: Wang et al (2008); Shekhar et al (2012); Amr et al (2013). 7= 111.399 (8) V = 844.01 (11) Å 3 Z = 2 Mo K radiation = 0.10 mm À1 T = 295 K 0.30 Â 0.20 Â 0.10 mm…”

3-Amino-1-(4-fluorophenyl)-7-methoxy-1H-benzo[f]chromene-2-carbonitrile

“…1, the furan ring has a flattened half-chair conformation with the methine-C11 atom lying only 0.136 2 177.17 (19)°. The structure described here resembles very closely those of the 4-bromo (Wang et al, 2008) and 2-CF 3 (Shekhar et al, 2012) where both the donor atom and acceptor-π system are derived from fluorobenzene rings, Fig. 3 and Table 1, highlighting the key role this residue plays in consolidating the crystal structure of (I).…”

“…For a related structure and background to 4H-chromene derivatives, see: El-Agrody et al (2013). For related structures, see: Wang et al (2008); Shekhar et al (2012) Table 1 Hydrogen-bond geometry (Å , ).…”

Evaluation of antibacterial, cytotoxicity, and apoptosis activity of novel chromene-sulfonamide hybrids synthesized under solvent-free conditions and 3D-QSAR modeling studies

“…Moreover, Chromene derivatives are an essential class of oxygen-containing heterocyclic compounds that have attracted researcher's attention because of their applications in pigments, cosmetics, and agrochemicals, and their wide range of biological activities 17 , 18 like anti-diabetic 19 , antibacterial 20 , antioxidant 21 , anti-cancer 22 and antiviral activities 23 . Given that chromene sulfonamide hybrids have been shown variable biological activities 24 – 26 , and based on our previous works on the synthesis of sulfonamide hybrids 27 – 31 , accordingly, we were motivated to design and synthesize some novel derivatives of these hybrids (Scheme 1 ).…”