Ultrasound-assisted synthesis of 2,2'-(2-oxoindoline-3,3-diyl)bis(1H-indene-1,3(2H)-dione) derivatives.

A simple and efficient procedure for the synthesis of 2,2'-(2-oxoindoline-3,3-diyl)bis(1H-indene-1,3(2H)-dione) derivatives, 2,2'-(2-oxo-1,2-dihydroacenaphthylene-1,1-diyl)bis(1H-indene-1,3(2H)-dione) and 2,2'-(1,3-dioxo-2,3-dihydro-1H-indene-2,2-diyl)bis(1H-indene-1,3(2H)-dione) by the reaction of 1,3-indandione and isatins or acenaphthylene-1,2-dione or ninhydrine in ethanol under ultrasonic irradiation in the presence of p-TSA is reported. The advantages of this method are the use of an inexpensive and readily available catalyst, easy work-up, good yields, and the use of ethanol as a solvent that is considered to be relatively environmentally benign.

Chromeno[2,3-d]pyrimidine-triones synthesis by a three-component coupling reaction.

A simple and one-pot synthesis of new chromeno[2,3-d]pyrimidine-triones by a three-component condensation reaction of barbituric acids, aldehydes and cyclohexane-1,3-diones in refluxing ethanol in the presence of p-toluenesulfonic acid (p-TSA) for 3-10 h is reported. Two cyclohexane-1,3-diones, four barbituric acids and six substituted aldehydes were chosen for the library validation. Prominent among the advantages of this new method are operational simplicity, good yields and easy work-up procedures employed.

WITHDRAWN: Sonochemical three-component synthesis of pyrazolotriazoles.

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