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چکیده
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The isomeric O-alkylated phenols have numerous industrial applications, particularly in the production of dyes and agrochemicals [1]. Although numerous reactions of phenols with activated alkynes have been reported, many of them suffer problems including low product yield, long reaction time, harsh reaction conditions or lack of selectivity [2]. Recently, the use of ionic liquids as solvent and catalyst has attracted much attention in the context of green synthesis [3]. Tetra-n-butylammonium bromide (TBAB) and related ionic liquids have considerable interest as potential ecofriendly reagents due to their lack of measurable vapor pressure. Recently TBAB has been used as an extremely useful catalyst in various organic transformations [4]. In this work we wish to report nucleophilic conjugate addition of various substituted phenols to alkyl propiolates in the presence of tetrabutylammonium bromide (TBAB) and trimethylamine under solvent-free conditions at room temperature leads to alkyl 3-aryloxypropanoate in excellent yields within 5-10 min.
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