Amidoalkyl naphthols

Shaterian HR, Yarahmadi H, Ghashang M (2008) An efficient, simple and expedition synthesis of 1-amidoalkyl-2-naphthols as drug like molecules for biological screening. Bioorg Med Chem Lett 18 788-792... 

Compounds containing 1,3-anfino-oxygenated functional groups are frequently found in biologically active natural products and potent drugs such as nucleoside antibiotics and HIV protease inhibitors. Furthermore, 1-amidoalkyl 2-naphthols can be converted to useful and important biological building blocks and to 1-amino methyl 2-naphthols by an amide hydrolysis reaction since compounds exhibit depressor and bradycardia effects in humans. 

Hajipour AR, Ghayeb Y, Sheikhan N, Ruoho AE (2009) Bronsted acidic ionic liquid as an efficient and reusable catalyst for one-pot synthesis of 1-amidoalkyl 2-naphthols under solvent-free conditions. Tetrahedron Lett 50 5649-5651... 

They reported for the first time a very simple and efficient methodology for the high-yielding synthesis of amidoalkyl naphthols by the straightforward one-pot... 

IL = (CH3CH2)3NCH2(CH2)2CH2S03H HSO4 Fig. 12.67 Synthesis of amidoalkyl naphthol derivatives in the presence of [TEBSA][HSOJ... 

Sapkal SB, Shelke KF, Madje BR, Shingate BB, Shingare MS (2009) l-Butyl-3-methyl imida-zohum hydrogen sulphate promoted one-pot three-component synthesis of amidoalkyl naphthols. BuU Korean Chem Soc 30 2887-2889... 

However, Hmited work has appeared with the carbon nucleophiles. Recently, an efficient tandem process has been developed that would allow the reaction of o-QM intermediates with carbon/nitrogen nucleophiles in situ to provide xanthene, naphtho(pyrano)pyridine/amidoalkyl naphthol derivatives under solvent-free and simple reaction conditions (Scheme 7.63). Xanthenes and benzoxanthenes are... 

Based on this concept, Murthy and coworkers reported an intriguing reaction for the synthesis of amidoalkyl naph-thols under solvent-free conditions [54], As shown in Scheme 11.10, p-naphthol 69, alkyl/aryl aldehydes 53, and amides/thioureas 68 were stirred at room temperature and catalyzed by sihca sulfuric acid (SS A). The three-component reaction afforded amidoalkyl naphthols 70 in excellent yields (79-92%). 

Shaterian and co-workers [180] have described an efficient and expeditious route towards the synthesis of l-amidoalkyl-2-naphthols 127 via a three-component reaction of an aryl aldehyde, 2-naphthol and acetamide in the presence of Fe(HS04)3 using a domestic microwave oven. The reaction of 2-naphthol with an aromatic aldehyde in the presence of an acid catalyst gives an o-quinone methide that is subsequently reacted with acetamide to give the desired product 127. This solvent-free microwave-assisted green procedure offers the advantages of short... 

The reaction of 2-naphthol with aromatic aldehydes in the presence of acid catalyst is known to provide ortho-quinone methides (o-QMs). The o-QMs were reacted with amides or urea to produce l-amidoalkyl-2-naphthol derivatives (Fig. 12.68). 

A green synthesis of 3-aryl-4-phenylsulfonyl-5-aminoisoxazoles utilised from a-chlorooximes and 2-phenylsulfonyl acetonitrile in the presence of Et3N. The corresponding amides were tested for cytotoxic activity against some cancer cell lines (14T3590). l-Arylnaphtho[l,2-d]isoxazoles were prepared via oxidation of l-amidoalkyl-2-naphthols with (diacetoxyiodo) benzene (14S752). 

An organocatalytic method has been developed which utilizes the Lewis acidic character of the trityl cation. For example, -naphthol condenses with benzaldehyde and acetamide to give the l-amidoalkyl-2-naphthol product (215). The synthesis is done under solvent-free conditions at 70 °C. The trityl chloride ionizes in the mixture to form the carbocation and this coordinates to the benzaldehyde to initiate the conversion. 

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