Synthesis and characterization of 2,5-diphenyl-3,4-di(2-pyridyl)cyclopentadienone by thermal dehydration of 2,5-diphenyl-3,4-di(2-pyridyl)cyclopentandiolone in the presence of silica gel
M. Amirnasr et A. Gorji, Synthesis and characterization of 2,5-diphenyl-3,4-di(2-pyridyl)cyclopentadienone by thermal dehydration of 2,5-diphenyl-3,4-di(2-pyridyl)cyclopentandiolone in the presence of silica gel, THERMOC ACT, 354(1-2), 2000, pp. 31-38
The compound, 2,5-diphenyl-3,4-di(2-pyridyl)cyclopentadienone (2), has been
synthesized by thermal dehydration of 2,5-diphenyl-3,4-di(2-pyridyl)cyclop
entandiolone (1) over silica gel under N-2 atmosphere at 200 degrees C. The
product (2), has been characterized by elemental analysis, IR, UV-VIS, and
H-1 NMR spectroscopy. Thermal dehydration of (1) over silica gel has also
been studied by TGA, DTG, and DSC. The effective kinetic and thermodynamic
parameters of dehydration have been estimated, and a mechanism of dehydrati
on from Bronsted sites on silica gel has been proposed. Comparative dehydra
tion experiments using gamma-Al2O3, ZnO, and NiSO4 proved silica gel to be
superior in converting compound (1) to (2). (C) 2000 Elsevier Science B.V.
All rights reserved.