SINTESIS DAN ELUSIDASI STRUKTUR SENYAWA ANALOG KURKUMIN SIMETRIS DARI BAHAN DASAR 3,4-DIMETOKSIBENZALDEHIDA DAN KETON (SIKLOHEKSANON DAN SIKLOPENTANON) DENGAN KATALIS KALIUM HIDROKSIDA - Nafillah, K.; Anisa, D. N.; Sari, D. W.; Noviarianto, N. (Jurnal Kimia (Journal of Chemistry), 2025)
Sintesis analog kurkumin simetris dari bahan dasar 3,4-dimetoksibenzaldehida dan keton (sikloheksanon dan siklopentanon) telah dilakukan. Senyawa A (2,6-bis(3,4-dimetoksibenzilidin)sikloheksanon) dan B (2,6-bis(3,4-dimetoksibenzilidin)siklopentanon) disintesis menggunakan reaksi kondensasi  Claisen-Schmidt  dari bahan dasar turunan benzaldehida dan keton, katalis kalium hidroksida (KOH) 8% dan pelarut etanol. Hasil penelitian menunjukkan bahwa senyawa analog kurkumin simetris A dan B berupa serbuk kuning dan orange dengan rendemen sebesar 26,39% dan 18,42%. Reaksi pada sintesis senyawa analog kurkumin A dan B dimonitor dengan plat  Thin Layer Chromatography  (TLC) menggunakan eluen etil asetat dan  n -heksana. Titik leleh senyawa A berada pada interval 140-146 °C dan senyawa B berada pada interval 186-189 °C. Kemudian elusidasi struktur dilakukan menggunakan  Fourier Transform Infra Red  (FT-IR),  Direct Inlet Mass Spectrometry  (DI-MS),  Proton   Nuclear Magnetic Resonance  ( 1 H-NMR) dan   Carbon-13 Nuclear Magnetic Resonance  ( 13 C-NMR). Spektra FT-IR senyawa A dan B menunjukkan adanya vibrasi dari gugus fungsi C sp3 -H, C=O karbonil, C=C aromatis dan C-O eter. Berdasarkan analisis DI-MS senyawa A dan B menunjukkan berat molekul berturut-turut 394 g/mol dan 380 g/mol. Spektra  1 H-NMR dan  13 C-NMR pada analog kurkumin simetris A dan B menunjukkan adanya H? dan karbon yang mengikat H?. Berdasarkan hasil elusidasi struktur menunjukkan bahwa senyawa analog kurkumin simetris A (2,6-bis(3,4-dimetoksibenzilidin)sikloheksanon) dan analog kurkumin simetris B (2,6-bis(3,4-dimetoksibenzilidin)siklopentanon) berhasil disintesis. Kata kunci : sintesis, elusidasi, analog kurkumin, 3,4-dimetoksibenzaldehida ABSTRACT            The synthesis of symmetric curcumin analogues from 3,4-dimethoxybenzaldehyde and ketones (cyclohexanone and cyclopentanone) has been carried out. The compounds A (2,6-bis(3,4-dimethoxybenzylidine)cyclohexanone) and B (2,6-bis(3,4-dimethoxybenzylidine)cyclopentanone) were synthesized using the Claisen-Schmidt condensation reaction of benzaldehyde derivatives and ketone, potassium hydroxide catalyst (KOH) 8% and ethanol solvent. The results showed that the powder of symmetric curcumin analogue compounds A and B were yellow with yields of 26.39% and 18.42%, respectively. The synthesis reactions of curcumin analogue compounds A and B were monitored by Thin Layer Chromatography (TLC) plates using ethyl acetate and  n -hexane as eluents. The melting point of compound A was in the interval of 140-146 °C, and compound B was in the interval 186-189 °C. The structure elucidation was carried out using Fourier Transform Infrared (FTIR), Direct Inlet Mass Spectrometry (DI-MS), Proton Nuclear Magnetic Resonance ( 1 H-NMR), and Carbon-13 Nuclear Magnetic Resonance ( 13 C-NMR). The FTIR spectra of compounds A and B showed the vibrations of the Csp3-H, C=O carbonyl, C=C aromatic, and C-O ether functional groups. Based on the DI-MS analysis, compounds A and B had molecular weights of 394 g/mol and 380 g/mol, respectively. The  1 H-NMR and  13 C-NMR spectra of symmetric curcumin analogues A and B showed the presence of H? and H?-binding carbon. Based on the results of the structure elucidation, the symmetrical curcumin analog compound A (2,6-bis(3,4-dimethoxybenzylidine)cyclohexanone) and the symmetrical curcumin analog B (2,6-bis(3,4-dimethoxybenzylidine)cyclopentanone) were successfully synthesized. Keywords : synthesis, elucidation, curcumin analogs, 3,4-dimethoxybenzaldehyde