Article ID Journal Published Year Pages File Type
1265375 Ultrasonics Sonochemistry 2012 5 Pages PDF
Abstract

A new, selective, straightforward and general method for preparation of highly functionalized coronands or spiro derivatives bearing 1,2-dihydroxyacetophenone unit, under conventional conditions and ultrasonic irradiation, is reported. The reaction setup involves only one step, acylation of an α-chloro-3,4-dihydroxyacetophenone with phthaloyl dichloride derivatives. 1,3- and 1,4-Phthaloyl dichloride derivatives leads to coronands only, while 1,2-phthaloyl dichlorides lead either to coronands or to spiro derivatives. A feasible explanation for the different behavior between conventional and ultrasound methods could be the different reaction mechanism involved in the two procedures: tetrahedral nucleophilic substitution under conventional conditions and radical substitution under ultrasound. Ultrasound induces a remarkable acceleration of the reactions (from days to minutes) and, most significantly, the yields are twice as high. A feasible explanation for the efficiency of the reactions under ultrasonic irradiation is presented.

Graphical abstractA new, selective, straightforward and general method for the preparation of highly functionalized coronands and spiro derivatives bearing the 1,2-dihydroxyacetophenone unit, under conventional conditions and ultrasonic irradiation, is reported.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► A new method for preparation of coronands or spiro derivatives is reported. ► The reactions took place both under conventional conditions and ultrasound irradiation. ► Ultrasound induces a remarkable acceleration of the reactions and the yields are twice as high. ► A feasible explanation for the efficiency of the reactions under ultrasound irradiation is presented.

Related Topics
Physical Sciences and Engineering Chemistry Chemistry (General)
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