A highly practical and efficient preparation of pyrano[3,2-c]pyridone and pyrano[3,2-c]quinoline derivatives was developed via an ionic liquid mediated and promoted multi-component reaction of malononitrile, aldehyde, and 4-hydroxyquinolin-2(1H)-one or 4-hydroxy-6-methylpyridin-2(1H)-one. The combinatorial syntheses were achieved for the first time without applying extra activation energy at ambient temperature while making use of [BMIm]Cl as a catalyst solvent.
A simple, novel, efficient and three-component procedure for the synthesis of pyrimido[4,5-d]pyrimidine-2,4-dione derivatives by the reaction of 6-amino-1,3-dimethyluracil, aldehyde and 2-benzylisothiourea hydrochloride promoted by ionic liquid 1-butyl-3-methylimidazolium bromide ([BMIm]Br) under solvent-free conditions is reported. The presented method is benefited from operational simplicity, simple workup and reusability of ionic liquid. These products were evaluated in vitro […]
An efficient and green method for the synthesis of pyrano[3,2-c]chromene or pyrano[4,3-b]pyrone derivatives is described by using a three-component condensation process of malononitrile, aldehyde, and 4-hydroxycoumarine or 4-hydroxypyrone in [BMIm]BF4-LiCl as an ionic liquid.
A practical and green method for the synthesis of 5H-dibenzo[b,i]xanthene-tetraones and spiro[dibenzo[b,i]xanthene-13,3′-indoline]-pentaones by the condensation of 2-hydroxynaphthalene-1,4-dione with aldehydes or isatins, respectively, in the presence of a catalytic amount of cellulose sulfuric acid (CSA) under solvent-free conditions at 100 °C is described. The significant features of this procedure are high yields of the products, simple […]
Cellulose sulfuric acid was used as an efficient biopolymer-based catalyst for the synthesis of tetrahydropyrimido[4,5-b]quinoline-2,4,6-triones and hexahydro-2H-pyrazolo[5,4-b]quinoline-6-ones via three component reaction of aldehyde, 5,5-dimethyl-1,3-cyclohexadione and 6-amino-1,3-dimethyluracil or 5-amino-3-methyl-1-phenypyrazole under solvent-free conditions at 90 oC. The major advantages of the present method are simple experimentation, use of inexpensive and eco-friendly reusable catalyst with good yields and […]
The Brønsted acidic ionic liquid ([BMIm]HSO4) catalyzed three-component synthesis of 2H-indazolo[2,1-b]phthalazine-trione derivatives at room temperature. The integrity of the ionic liquid remains reasonably unchanged when it is separated from the reaction mixture by water extraction, as it can be recycled several times without any loss of activity in each of the title syntheses. The products […]
The ionic liquid Li(OHCH2CH2NH2)(CF3OAC) was found to efficiently catalyze the three-component reaction between different enols, aldehydes, and malononitrile , leading to rapid synthesis of 2-amino-4H-chromene derivatives in fairly high yields. The catalyst is easily prepared, highly stable, simple to handle and recycled for several times without significant loss of activity. The method is simple, starts […]
A green and efficient one pot, three component protocol for synthesis of naphthopyranopyrimidines by cyclocondensation of β-naphthol, aldehyde, and 6-amino-1,3-dimethyluracil using L-proline as a beneficial catalyst with high catalytic activity under solvent-free conditions at 100 °C is described. In this study, several types of aromatic aldehyde, containing electron-withdrawing groups as well as electron-donating groups, were […]
