Sintesis 2-Benzil-3-benzilidenisoindolinon melalui One-pot Reaction

NUR ANNISA ZAENAB, Dr. Muhammad Idham Darussalam Mardjan, S.Si., M.Sc.; Drs. Bambang Purwono, M.Sc., Ph.D.

2019 | Skripsi | S1 KIMIA

Telah dilakukan penelitian mengenai sintesis 2-benzil-3-benzilidenisoindolinon melalui one-pot reaction. Penelitian ini bertujuan untuk mensintesis senyawa 3-benzilidenftalida melalui reaksi Sonogashira, mensintesis 2-benzil-3-benzilidenisoindolinon melalui reaksi dua tahap yaitu reaksi adisi nukleofilik dan β-eliminasi. Selain itu, penelitian ini juga bertujuan untuk mensintesis 2-benzil-3-benzilidenisoindolinon melalui one-pot reaction yang menggabungkan reaksi adisi nukleofilik dan β-eliminasi. Sintesis senyawa 3-benzilidenftalida dilakukan melalui reaksi Sonogashira dengan mereaksikan asam 2-iodobenzoat dan fenilasetilena dalam pelarut DMSO dengan adanya basa NaHCO3 dan katalis CuI, pada temperatur ruang selama 24 jam. Reaksi adisi nukleofilik antara 3-benzilidenftalida dan benzilamina dilakukan dalam pelarut i-PrOH pada 50ºC selama 24 jam guna menghasilkan 2,3-dibenzil-3-hidroksiisoindolinon. Selanjutnya, reaksi β-eliminasi dilakukan dengan memanaskan 2,3-dibenzil-3-hidroksiisoindolinon dengan katalis HCl 6 M pada 50ºC selama 3 jam untuk menghasilkan 2-benzil-3-benzilidenisoindolinon. Sintesis 2-benzil-3-benzilidenisoindolinon melalui one-pot reaction dilakukan dengan mereaksikan 3-benzilidenftalida dan benzilamina pada 50ºC selama 17 jam, dilanjutkan dengan penambahan HCl 6 M dan pemanasan selama 5 jam. Karakterisasi masing-masing produk dilakukan dengan uji titik lebur, spektrometer FTIR, 1H-NMR, dan 13C-NMR. Reaksi Sonogashira antara asam 2-iodobenzoat dan fenilasetilena menghasilkan 3-benzilidenftalida berupa padatan kuning dengan persen hasil 64%. Reaksi adisi nukleofilik antara 3-benzilidenftalida dan benzilamina menghasilkan 2,3-dibenzil-3-hidroksiisoindolinon berupa padatan coklat muda dengan persen hasil 76%. Reaksi β-eliminasi antara 2,3-dibenzil-3-hidroksiisoindolinon terkatalisis HCl menghasilkan 2-benzil-3-benzilidenisoindolinon berupa padatan putih dengan persen hasil 71%. Persen hasil total dalam sintesis 2-benzil-3-benzilidenisoindolinon melalui reaksi dua tahap yaitu sebesar 53%. One-pot reaction antara 3-benzilidenftalida dan benzilamina menghasilkan 2-benzil-3-benzilidenisoindolinon berupa padatan putih gading dengan persen hasil 77%. Berdasarkan perbandingan persen hasil antara reaksi dua tahap dan one-pot reaction, maka one-pot reaction lebih efektif, efisien dan ramah lingkungan.

Synthesis of 2-benzyl-3-benzylideneisoindolinone via one-pot reaction has been conducted. This research was aimed to synthesize 3-benzylidenephthalide via the Sonogashira reaction, to synthesize 2-benzyl-3-benzylinedeisoindolinone via a two-stage reaction, comprising nucleophilic addition and β-elimination reactions. In addition, this study was also aimed to synthesize 2-benzyl-3-benzylidenisoindolinone via one-pot reaction which combines nucleophilic addition and β-elimination reactions. Synthesis of 3-benzylidenephthalide was carried out via the Sonogashira reaction by reacting 2-iodobenzoic acid and phenylacetylene in DMSO in the presence of NaHCO3 and CuI as catalyst, at room temperature for 24 h. The nucleophilic addition reaction between 3-benzylidenephthalide and benzylamine was performed in i-PrOH at 50ºC for 24 h to produce 2,3-dibenzyl-3-hydroxyisoindolinone. Furthermore, the β-elimination reaction was carried out by heating 2,3-dibenzyl-3-hydroxyisoindolinone with a HCl 6 M as catalyst at 50ºC for 3 h. Synthesis of 2-benzyl-3-benzylideneisoindolinone via one-pot reaction was done by reacting 3-benzylidenephthalide and benzylamine at 50ºC for 17 h, followed by the addition of 6 M HCl and heating for 5 h. The characterization of the products was carried out by means of melting point tests, 1H-NMR, 13C-NMR, and FTIR spectrometers. The Sonogashira reaction between 2-iodobenzoic acid and phenylacetylene produced 3-benzylidenephthalide as yellow solid in 64% yield. The nucleophilic addition reaction between 3-benzylidenephthalide and benzylamine generated 2,3-dibenzyl-3-hydroxyisoindolinone as light brown solid in 76% yield. The β-elimination reaction of 2,3-dibenzyl-3-hydroxyisoindolinone in the presence of HCl catalyst, gave 2-benzyl-3-benzylideneisoindolinone as white solid in 71% yield. The total yield of the synthesis of 2-benzyl-3-benzylidenisoindolinone via a two-stage reaction was 53%. The one-pot reaction between 3-benzylidenephthalide and benzylamine produced 2-benzyl-3-benzylideneisoindolinone as ivory white solids in 77% yield. By comparing the yield of reaction, the one-pot reaction is proven to be more effective, efficient and environmentally friendly.

Kata Kunci : 2-benzil-3-benzilidenisoindolinon, one-pot reaction, beta-eliminasi, adisi nukleofilik, Sonogashira