Synthesis, the spectral and thermal analysis of (2E,5E)2,5-bis(3R,5R-4-hydroxy benzylidene)cyclopentanone

ABSTRACT

(2E,5E)2,5-Bis(3R,5R-4-hydroxy benzylidene)cyclopentanone (BHCP: R=H and BrBHCP: R=Br) was synthesized by reacting 4-hydroxybenzaldehyde with cyclopentanone using boric acid (in hydrochloric acid) as a catalyst at 60-70 °C for 1h. BHCP was brominated in glacial acetic acid at reflux temperature for 1h. The structures of BHCP and BrBHCP were supported by spectral techniques: UV-Visible, FTIR, ¹HNMR, ¹³CNMR, and MS. DSC analysis did not show distinct melting transitions which means they started decomposing before their melting points. BHCP and BrBHCP followed two-step degradation kinetics with fractional order degradation reactions. BHCP displayed much more thermal stability than Br BHCP. High magnitudes of the energy of activation indicated their rigid nature.