Solvent‐Free One‐Pot Synthesis of Amidoalkyl Naphthols Catalyzed by Silica Sulfuric Acid

Abstract

An efficient, inexpensive, and mild method for the synthesis of amidoalkyl naphthols, catalyzed by silica sulfuric acid (SSA), was elaborated under solvent-free conditions at room temperature. Various amidoalkyl naphthols were synthesized in high yields from aromatic or aliphatic aldehydes, a-or bnaphthols, and amides or urea or thiourea.

Sodium hydrogen sulfate as effective and reusable heterogeneous catalyst for the one-pot preparation of amidoalkyl naphthols

“…Yields refer to the pure isolated products. All known products have been reported previously in the literature and were characterized by comparison of IR and NMR spectra with authentic samples [15][16][17][18][19][20][21][22]. Method A: the reaction was carried out with 45mg of NaHSO 4 As shown in Table 1, the three-component reaction of 2-naphthol, arylaldehydes, and acetonitrile (reactant as well as solvent, 5 mL) or acetamide was performed in the presence of sodium hydrogen sulfate (45 mg).…”

“…19 and sulfamic acid, 20 cation-exchanged resins 21 and silica-sulfuric acid. 22 However, many of these methodologies suffer from the drawback of green chemistry 16,17,23 and have been associated with several short comings such as long reaction times, expensive reagents, low product yields and difficulty in recovery and reusability of the catalysts. Due to these problems, development of an efficient and versatile method for the preparation of amidoalkyl-2-naphthols is an important aspect and which is an active going on research area and there is a scope for the further improvement towards mild reaction conditions and improved yields.…”

Heteropoly acid catalyzed synthesis of 1-amidoalkyl-2-naphthols in the presence of molten tetraethyl ammonium chloride as an ionic liquid

“…8 Sulfamic acid 9 and cation-exchange resins. 10 One of the major drawbacks of these reactions is that in some cases when a solid aldehyde or high amounts of catalyst is used, an organic solvent such as…”

Incredible Role of Glycerol in Multicomponent Synthesis of 2,3-Dihydroquinazoline-4(1H)-ones and 1-Amidoalkyl-2-naphthols

“…27 Glycerol is a simple polyol compound. It is a colorless, odorless, viscous liquid that is widely used in pharmaceutical formulations.…”