1-Butyl-3-Methyl Imidazolium Hydrogen Sulphate Promoted One-Pot Three-Component Synthesis of Amidoalkyl Naphthols

Abstract

An efficient and easy method for one-pot three-component synthesis of amidoalkyl naphthols by the condensation of aromatic/heteroaromatic/aliphatic aldehydes, 2-naphthol and amides or urea under thermal condition at 60 o C in the presence of acidic ionic liquid 1-butyl-3-methylimidazolium hydrogen sulphate ([bmim]HSO4) has been described.

One-Pot Mannich Base Synthesis Using Task Specific Protic Ionic Liquids

“…In this context, Mannich type reactions have also been reported in water [10]. In current years, ionic liquids (ILs) have been used as an environmentally benign solvents, efficient catalysts and a promising substitutes for volatile organic solvents and traditionally used acid/ base catalysts in construction of organic moieties [11,12]. Use of organic solvents in reaction mixture usually leads to serious safety issues such as volatility, flammability and toxicity [12,13].…”

“…In current years, ionic liquids (ILs) have been used as an environmentally benign solvents, efficient catalysts and a promising substitutes for volatile organic solvents and traditionally used acid/ base catalysts in construction of organic moieties [11,12]. Use of organic solvents in reaction mixture usually leads to serious safety issues such as volatility, flammability and toxicity [12,13]. The use of ionic liquids as reaction media offers a convenient solution to both solvent emission and catalytic recycling problems [10].…”

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

“…By attaching different functional groups on the cation, ionic liquids, able to perform a specific task can be obtained. However these protocols [37][38][39][40][41][42] have several drawbacks like, use of aldehyde, high toxicity, corrosion, catalyst waste, use of toxic organic solvents, rigorous condition, high reaction temperature, long reaction times, byproduct formation, difficulty in separation and recovery. Davis and co-workers introduced task-specific ionic liquids.…”

“…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.…”

Zinc Benzenesulfonate–Promoted Eco-Friendly and Efficient Synthesis of 1-Amidoalkyl-2-naphthols

“…When benzamide was used as an amine component, both aromatic aldehydes and aliphatic aldehydes worked well, affording moderate to good yields of corresponding products ( Table 2, entries 1-12). The condensation yields with acetamide were lower than those with benzamide and urea ( Table 2, entries [16][17][18][19][20]. In addition to urea, the amidoalkylation of thiourea with 2-napthol and benzaldehyde was also investigated, and no corresponding products were isolated.…”