An efficient synthesis of 1,8-dioxo-octahydro-xanthene derivatives promoted by a room temperature ionic liquid at ambient conditions under ultrasound irradiation

作者：Venkatesan K; Pujari Suresh S; Lahoti R J; Srinivasan K V^*

来源：Ultrasonics Sonochemistry, 2008, 15(4): 548-553.

DOI：10.1016/j.ultsonch.2007.06.001

• aldehydes
• dimedone
• xanthenes
• ionic liquid
• Bronsted acidity
• ultrasound
• ambient conditions

The condensation reaction involving an aldehyde and diketone was efficiently promoted by the Ionic liquid, [Hbim]BF(4) (IL) as a reaction medium with methanol as co-solvent at ambient temperature under ultrasonic irradiation to afford the corresponding 1,8-dioxo-octahydroxantliene (xanthene) derivatives in excellent yields. The advantages of this method include among others the use of a recyclable, non-volatile ionic liquid, which promotes this protocol under ambient temperature without the requirement of ally added catalyst. The reaction times and yields are compared with p-TSA catalyzed synthesis of xanthenes under thermal conditions, which is also reported for the first time under our reaction conditions.

• 出版日期2008-4