General Papers ARKIVOC 2008 (ii) 134-140
NaHSO4•H2O as an efficient and eco-friendly catalyst for the one-pot multicomponent synthesis of ß-acetamido ketones under mild and heterogeneous conditions
Asadollah Hassankhani, Malek Taher Maghsoodlou,* Sayyed Mostafa Habibi-Khorassani, Hassan Hosseini-Mahdiabad, and Ghasem Marandi
Department of Chemistry, University of Sistan and Balouchestan, P. O. Box 98135-674, Zahedan, Iran E-mail:
[email protected]
Abstract
A new, one-pot, four-component condensation of benzaldehyde derivatives, acetophenone derivatives, acetyl chloride and acetonitrile in the presence of sodium hydrogen sulfate as catalyst is described for the synthesis of ß-acetamido ketones.
Keywords: ß-Acetamido ketones, multicomponent reactions, acetyl chloride, NaHSO4·H2O
Introduction
Multicomponent reactions (MCRs) play a key role in organic chemistry due to the fact that highly complex structures can be formed in a simple one-pot process.1 MCRs contribute to the requirements of an environmentally friendly process by reducing the number of synthetic steps, energy consumption and waste production. Researchers have transformed this powerful technology into one of the most efficient and economic tools for combinatorial and parallel synthesis.2,3 Due to their inherent simple experimental procedures and their one-pot character, they are perfectly studied for automated synthesis. Thus, MCRs have attracted considerable interest owing to their exceptional synthetic efficiency.4
Acetamido- or amino- ketone derivatives are important for their biological and pharmaceutical properties,5,6 and in the preparation of antibiotic drugs such as nikkomycine or neopolyoxines.7,8 The best known route for the synthesis of this class of compounds is the Dakin–West reaction,9 the condensation of an a-amino acid with acetic anhydride in the presence of a base provides the a-acetamido ketones via an azalactone intermediate.10 The simple and direct method for the synthesis of ß-acetamido ketones reported by Iqbal and coworkers in 1994 involves the one-pot condensation of a ketone, aldehyde and acetonitrile in the presence of acetyl chloride.11
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