SINTESIS 1-BENZIL-3-METIL-6,7-DIMETOKSI-3,4-DIHIDROISOKUINOLINA DARI METILEUGENOL

NOVA RIFATUL ULYA, Prof. Drs. Sabirin Matsjeh, Ph.D.,

2013 | Tesis | S2 Ilmu Kimia

Telah dilakukan sintesis senyawa 1-benzil-3-metil-6,7-dimetoksi-3,4- dihidroisokuinolina dari bahan dasar metileugenol melalui beberapa tahap reaksi yaitu reaksi adisi, hidrolisis, reaksi Ritter dan siklisasi. Senyawa 1-benzil-3-metil-6,7- dimetoksi-3,4-dihidroisokuinolina merupakan senyawa turunan isokuinolina yang memiliki potensi sebagai senyawa obat. Sintesis 1-benzil-3-metil-6,7-dimetoksi-3,4-dihidroisokuinolina dilakukan dengan menkonversi gugus allil metileugenol menjadi alkohol sekunder melalui reaksi Ritter dengan benzil sianida dan reaksi siklisasi dengan asam sulfat. Alkohol sekunder diperoleh melalui dua tahap. Tahap pertama yaitu reaksi adisi dengan asam format, kemudian diikuti tahap kedua yaitu reaksi hidrolisis dalam larutan kalium hidroksida. Reaksi selanjutnya yaitu reaksi Ritter pada alkohol sekunder kemudian siklisasi senyawa amida hasil Ritter untuk dihasilkan senyawa isokuinolina. Reaksi adisi metileugenol dengan asam format menghasilkan senyawa 1-(3,4- dimetoksifenil)-2-propil format (86,46%). Reaksi hidrolisis 1-(3,4-dimetoksifenil)-2- propil format dengan KOH dihasilkan senyawa 1-(3,4-dimetoksifenil)-2-propanol (86,41%). Reaksi Ritter 1-(3,4-dimetoksifenil)-2-propanol dengan benzil sianida dihasilkan senyawa amida N-[1-metil-2-(3,4-dimetoksifenil)etil]-2-fenil asetamida (34,70%). Reaksi terakhir yaitu siklisasi senyawa amida dengan asam sulfat dihasilkan senyawa target isokuinolina 1-benzil-3-metil-6,7-dimetoksi-3,4- dihidroisokuinolina sebesar 39%. Elusidasi senyawa produk reaksi dianalisis dengan FTIR, GC-MS dan 1H-NMR.

A synthesis of 1-benzyl-3-methyl-6,7-dimethoxy-3,4-dihydroisoquinoline from methyleugenol as starting material is presented. The synthesis was carried out several reactions steps, these are addition reactions, hydrolysis, Ritter reaction and cyclization. The compound of 1-benzyl-3-methyl-6,7-dimethoxy-3,4- dihydroisoquinoline is isoquinoline derivative that have potential as drug compound. The synthesis of 1-benzyl-3-methyl-6,7-dimethoxy-3,4-dihydroisoquinoline from methyleugenol has been achieved through conversion of allyl group to secondary alcohol, followed by Ritter reaction with benzyl cyanide and cyclization reaction with sulfuric acid. The secondary alcohol has been achieved by two methods. The first method was formic acid addition reaction, and then the second method was hydrolysis in solution of potassium hydroxide. The next reaction was the Ritter reaction of the secondary alcohol and the last method was the cyclization reaction of amide to isoquinoline. The addition reaction of methyleugenol with formic acid yield 1-(3,4- dimethoxyphenyl)-2-propyl formate (86,46%). The hydrolysis of 1-(3,4- dimethoxyphenyl)-2-propyl formate with KOH produced 1-(3,4-dimethoxyphenyl)-2- propanol (86,41%). The Ritter reaction of 1-(3,4-dimethoxyphenyl)-2-propanol with benzyl cyanide gave (34,70%) N-[1-methyl-2-(3,4-dimethoxyphenyl)ethyl]-2-phenyl acetamide. And the last reaction is cyclization with sulfuric acid gave 1-benzyl-3- methyl-6,7-dimethoxy-3,4-dihydroisoquinoline as a main target in 39%. The structure elucidation of these product were analyzed by FTIR,1H-NMR, and GC-MS.

Kata Kunci : Metileugenol, Reaksi Ritter, Isokuinolina