A Simple and Efficient Procedure for the Synthesis of Amidoalkyl Naphthols by p-TSA in Solution or under Solvent-Free Conditions

Abstract

An efficient and direct procedure for the synthesis of amidoalkyl naphthols has been described that employs a three-component condensation reaction in one pot using aromatic aldehydes, b-naphthol and ureas or amides in the presence of p-toluene sulfonic acid in 1,2-dichloroethane at room temperature or under solventfree conditions at elevated temperature.

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

“…Finally solid product was recrystallized from ethanol (Scheme 1). Synthesized compounds were characterized by 13 CNMR and 1 HNMR analyses, and values were compared with the literature data of known products. …”

“…5 Also 2,3-Dihydroquinazolinone derivatives are an important class of fused heterocycles that display a wide range of biological, pharmacological, and medicinal properties involving antitumor, antibiotic, antipyretic, analgesic, antihypertonic, diuretic, antihistamine, antidepressant, and vasodilating activities. 6 The preparation of 1-amidoalkyl-2-naphthols can be carried out by the condensation of aryl aldehydes, 2-naphthol and acetonitrile or amide in the presence of Lewis or Brønsted acid catalysts 7 such as K-10 clay, 8 Ce(SO4)2, 9 iodine, 10 K5CoW12O40• 3H2O, 11 p-TSA, 12 sulfamic acid, 13 cation-exchanged resins, 14 silica-sulfuric acid, 15 silica supported dual acidic ionic liquid,…”

Ultrasound assisted synthesis of tetrahydrobenzo[c]xanthene-11-ones using CAN as catalyst

“…Different catalysts such as sulfamic acid [10], p-TSA [11], selectfluor TM [12], iodine [13], silica sulfuric acid [14], Yb(OTf) 3 [15] and ionic liquids [16] find application in the synthesis of benzo [a]xanthenes. The existing methods have not been conceded for the synthesis of tetrahydrobenzo [c]xanthene-11-ones from a-naphthol (Scheme 1), this is because, the electron density at the b-position of the a-naphthol is not sufficient for the formation of the corresponding ortho-Quinone Methides (o-QMs, Scheme 2) under these conditions.…”

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

“…2,3 The importance of amidoalkyl naphthols for their synthesis has attracted renewed attention and various improved procedures have been reported. Many of these reported methods employs catalysts, such as p-TSA, 4 iodine, 5 sulphamic acid, 6 montmorillonite K-10 clay, 7 Ce(SO4)2, 8 cation-exchanged resin, 9 zirconyl (IV) chloride, 10 PPA-SiO2, 11 H3PW12O40, 12 NaHSO4-SiO2, 13 and silica sulfuric acid.…”