Senyawa derivat spirooxindole merupakan senyawa heterosiklik, yang memilikiaktivitas biologi dan peran dalam farmasi karena kerangkanya. Sintesis derivatsenyawa spirooxindole dilakukan dengan sistem reaksi multikomponen (MCR), yangterdiri dari dua tahapan reaksi, yaitu kondensasi Knovenagel dan reaksi adisi-Michael. Tujuan penelitian ini adalah untuk mensintesis derivat senyawaspirooxindole dengan menggunakan nano TiO2/SiO2 sebagai katalis serta melakukanuji aktivitas antioksidan. Katalis nano TiO2/SiO2 disintesis menggunakan metode solgeldan dikarakterisasi dengan FT-IR, XRD, EDS, serta TEM. Selanjutnya, katalisdigunakan untuk sintesis derivat senyawa spirooxindole. Kondisi optimal diperolehdengan menggunakan 12,5% mol katalis TiO2/SiO2 pada suhu 50oC selama 4 jamdalam pelarut etanol dengan persen yield sebesar 86,81%. Kondisi reaksi tersebutdapat pula diterapkan pada prekursor lain berupa asam tiobarbiturat dan etilasetoasetat sebagai pengganti dari asam barbiturate dengan persen yield masingmasing64,69% dan 79,38%. Senyawa hasil sintesis dikonfirmasi menggunakaninstrument FT-IR, UV-Vis, uji titik leleh dan LC-MS/MS. Berdasarkan uji DPPH,diketahui bahwa derivate senyawa spirooxindole hasil sintesis memiliki potensisebagai senyawa antioksidan

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Spirooxindole derivatives are included in the heterocyclic group of compounds,

spirooxindole derivatives have biological activity and have an important role in the

pharmaceutical field because of their framework. The synthesis of spirooxindole

derivatives was carried out using a multicomponent reaction system (MCR), which

consists of two reaction stages, namely the Knovenagel condensation and the

Michael-addition reaction. The selection of the MCR method was made because this

system was considered to be more efficient, easier, and produced good yields in each

synthesis. The purpose of this study was to synthesize the derivatives of

spirooxindole compounds using nano TiO2 / SiO2 as a catalyst and to test the

antioxidant activity of the synthesized compounds. Nano TiO2 / SiO2 catalyst was

synthesized using the sol-gel method and characterized by FT-IR, XRD, EDS, and

TEM. Furthermore, the catalyst is used for the synthesis of spirooxindole compound

derivatives. The optimal conditions were obtained by using 12.5% mole of TiO2 /

SiO2 catalyst at 50oC for 4 hours in ethanol solvent with a percent yield of 86.81%.

The reaction conditions can also be applied to other precursors in the form of

thiobarbituric acid and ethyl acetoacetic as a substitute for barbiturate acid with the

percent yield of 64.69% and 79.38%, respectively. The synthesized compounds were

confirmed using the FT-IR, UV-Vis, melting point test and LC-MS / MS instruments.

Based on the DPPH test, it is known that the synthesized derivative of the

spirooxindole compound has potential as an antioxidant compound