Significant Efficacy of Desiccants in the Synthesis of Distyryl Ketones/Chalcones Bearing Phenolic Hydroxyl Groups

Abstract

Complicated catalysts or rigorous synthesis methods are commonly necessary for the synthesis of distyryl ketones and chalcones bearing phenolic hydroxyl groups. Boron trifluoride etherate can serve as a type of high-efficiency catalyst for the synthesis of those products, but it will be quickly deactivated by the produced water during the reactions. However, the addition of an excessive amount of this catalyst will lead to serious side reactions and waste. In this work, by promptly removing the water produced from the reactions with the aid of desiccants, the products distyryl ketone and chalcone bearing phenolic hydroxyl groups are synthesized in high yield, as exemplified by the synthesis of 1,5-bis(4-hydroxyphenyl) penta-1,4-dien-3-one and 1,3-bis (4-hydroxyphenyl) prop-2-en-1-one, each representing very typical types of phenolic hydroxyl groups containing distyryl ketones and chalcones. The effects of desiccant species and dosages have been studied. On this basis, the species of desiccant is optimized as CaCl 2 , and then its proper dosage and the corresponding optimal reaction conditions are achieved.

Synthesis, reactions and application of chalcones: a systematic review

“…Moreover, the synthesis of 2′-hydroxychalcones 26 was reported using Claisen–Schmidt condensation, 22,53,54 as shown in Scheme 4. Also, boron trifluoride etherate can be used as a high-efficiency catalyst to synthesize distyryl ketones and chalcones bearing phenolic hydroxyl groups in high yield by removing water produced during the reactions with the aid of desiccants such as CaCl 2 , leading to the synthesis of 1,5-bis(4-hydroxyphenyl) penta-1,4-dien-3-one 29 , 55 as shown in Scheme 5.…”