A study for the synthesis of dibenzo [a,j] xanthenes and 1-amidoalkyl 2-naphthols catalyzed by [Hmim][HSO4] as a green, efficient and reusable catalyst under solventfree conditions

Authors

• Leila Khazdooz ^{1, 2}
• Amin Zarei ³
• Abdol R. Hajipour ^{4, 5}
• Nafisehsadat Sheikhan ⁶

1. Department of Science, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan 81595-158, Iran
2. Laser and Biophotonics in Biotechnologies Research Center, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan 81595-158, Iran
3. Department of Science, Fasa Branch, Islamic Azad University, PO Box No. 364, Fasa 7461713591, Fars, Iran.
4. Pharmaceutical Research Laboratory, Department of Chemistry, Isfahan University of Technology, Isfahan 84156, Iran.
5. Department of Pharmacology, University of Wisconsin, Medical School, 1300 University Avenue, Madison, 53706-1532, WI, USA.
6. Department of Chemistry, Faculty of Sciences, Najafabad Branch, Islamic Azad University, Najafabad, Esfahan, P.O. Box 517, Iran.

Abstract

A convenient and efficient procedure for the synthesis of 14-aryl or alkyl-14H-dibenzo[a,j]xanthenes by condensation of 2-naphthol and aldehydes in the presence of Methylimidazolium hydrogensulfate, as a Brönsted acidic ionic liquid ([Hmim]HSO4), is described. Both aromatic and aliphatic aldehydes reacted easily to afford the corresponding 14-aryl or alkyl-14H-dibenzo[a,j]xanthenes in good yields under solvent-free conditions. Moreover, the synthesis of 1-amidoalkyl 2-naphthols is studied by condensation of aromatic aldehydes with amides or urea and 2-naphthol in the presence of [Hmim]HSO4. Using solventfree conditions, non-toxic and inexpensive materials, simple and clean work-up, short reaction times and high yields of the products are the advantages of this method.

Keywords

• Aldehyde
• Methylimidazolium hydrogen sulfate
• Dibenzoxanthene
• Amidoalkyl naphthols
• 2-Naphthol