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

Abstract

An efficient and direct procedure has been developed for the preparation of amidoalkyl naphthols by a one-pot condensation of aryl aldehydes, β-naphthol and urea or acetamide in the presence of 12-tungstophosphoric acid as a heterogeneous catalyst. The reaction was carried out in molten tetraethylammonium chloride under solvent-free condition.

One-pot synthesis of 1-amidoalkyl-2-naphthols catalyzed by melamine-Br3 under solvent-free conditions

“…Aromatic aldehydes bearing an electron-donating group, however, gave a slightly lower yield and required longer reaction time ( Table 2, entries 7-10). The optimized method also proceeded successfully when thioacetamide was used instead of acetamide in the reaction (Table 2, entries [11][12][13][14][15][16].…”

“…1-Amidoalkyl-2-naphthols can be prepared by the multicomponent condensation of aryl aldehydes with 2-naphthol and acetamide or thioacetamide in the presence of an appropriate catalyst such as RuCl2(PPh3)3 [6], sulfamic acid [7,8], Ce(SO4)2 [9], [FemSILP]-L-prolinate [10], Bi(NO3)3•5H2O [11], K5CoW12O40•3H2O [12], Hf(NPf2)4 [13], H3PW12O40 [14], Yb(OTf)3 [15], Fe(HSO4)3 [16], montmorillonite K10 clay [17], p-TSA [18], H4SiW12O40 [19], zeolite [20], 2,4,6-trichloro-1,3,5trizine [21], iodine [22], PFPAT [23], and poly(4-vinylpyridinium butane sulfonic acid) hydrogen sulfate [24].…”

“…J. Catal., 2014, 35: 1024-1029 doi: 10.1016/S1872-2067(14)60029amidoalkyl-2-naphthols catalyzed by melamine-Br3 under solvent-free conditions Arash Ghorbani-Choghamarani *, Shima Rashidimoghadam Ilam University…”

Choline peroxydisulfate oxidizing Bio-TSIL: triple role player in the one-pot synthesis of Betti bases and gem-bisamides from aryl alcohols under solvent-free conditions

“…Usually, these gem-bisamides and Betti bases are synthesized by the direct reaction of aldehydes with amides and 2-naphthol using different catalysts, such as H 2 SO 4 , 23 HCl, or strong acidic catalysts, such as triflic acids, 24 boric acid, 25 B(HSO 4 ) 3 , 26 phosphotungstic acid, 27 TEA-sulfonic acid, 28 iodine, heteropoly acid, 29 NMP HSO 4 , 30 SiO 2 -IL, 31 PEG-based dicationic acidic ionic liquids, 32 p-TSA, 33 zinc benzenesulfonate, 34 Fe(HSO 4 ) 3 , 35 or trityl chloride 36 at higher temperatures ranging from 100 to 150 1C. However, these protocols [37][38][39][40][41][42] have several drawbacks, such as the use of an aldehyde, high toxicity, corrosion, catalyst waste, use of toxic organic solvents, rigorous conditions, high reaction temperature, long reaction times, by-product formation, and difficulty in separation and recovery.…”

Novel Efficient Three-Component, One-Pot Synthesis of 3-(α-amidobenzyl)-4-hydroxycoumarin derivatives

“…A similar procedure has been recently used for the synthesis of 1-amidoalkyl-2-naphthols by three-component reaction of aryl aldehydes, 2-naphthols and amides or urea. 20,23…”