Sintesis 3-Fenil-3-Hidroksi-Propionitril sebagai salah satu senyawa antara sintesis 8-Aminoflavon

RAHMAYANTI, Maya, Dr. Jumina

2005 | Tesis | Ilmu Kimia

Telah dilakukan sintesis 3-fenil-3-hidroksi-propionitril sebagai salah satu senyawa antara sintesis 8-aminoflavon. Sintesis 3-fenil-3-hidroksi-propionitril dilakukan dalam tiga tahap, yaitu : (1) brominasi asetofenon menggunakan katalis aluminium klorida, (2) reaksi 2-bromo-1-fenil-etanon dengan natrium sianida, dan (3) reaksi reduksi 3-fenil-3-okso-propionitril dengan natrium borohidrida. Hidrolisis 3-fenil-3-okso-propionitril dilakukan dalam suasana asam maupun basa. Tahap (1) dilakukan pada suhu di bawah 2°C selama ± 3 jam dilanjutkan dengan rekristalisasi menggunakan metanol menghasilkan senyawa 2-bromo-1- fenil-etanon dengan rendemen 71,77%. Tahap (2) dilakukan pada suhu 40°C selama 3 jam menghasilkan senyawa 3-fenil-3-okso-propionitril dengan kemurnian 100%. Reaksi tanpa katalis menghasilkan rendemen produk 18,00%, dengan katalis tween 80 menghasilkan rendemen produk 58,05%. Tahap (3) dilakukan pada suhu kamar, 45-48°C dan 78-80°C masing-masing selama 2 jam, 1 dan 3 jam, dan 3 jam. Reaksi pada suhu kamar selama 2 jam menghasilkan produk campuran yang sulit diidentifikasi. Reaksi pada suhu 45-48°C selama 1 jam menghasilkan senyawa 3-fenil-3-hidroksi-propionitril dengan kemurnian 39,31% dan rendemen 34,82%. Reaksi dengan waktu reaksi 3 jam menghasilkan senyawa 3-fenil-3-hidroksi-propionitril dengan kemurnian 22,31% dan rendemen 19,63%. Reaksi pada suhu 78-80°C menghasilkan produk campuran yang sulit diidentifikasi. Hidrolisis 3-fenil-3-okso-propionitril dalam suasana asam dilakukan pada suhu 40-45°C dan 110-115°C. Hidrolisis pada suhu 40-45°C menghasilkan produk yang diduga mengalami dekarboksilasi menghasilkan asetofenon, begitu juga dengan hidrolisis pada suhu 110-115°C. Hidrolisis dalam suasana basa menghasilkan senyawa produk yang sulit diidentifikasi. Analisis produk dilakukan dengan spektroskopi infra merah (IR), spektroskopi proton resonansi magnetik inti (1H-NMR) dan kromatografi gas-spektroskopi massa (GC-MS).

It has been conducted the synthesis of 3-hydroxy-3-phenyl-propionitrile as one of the intermediate compounds for the synthesis of 8-aminoflavon. The synthesis of 3-hydroxy-3-phenyl-propionitrile was carried out in three steps i.e (1) bromination of acetophenone using aluminium chloride as catalyst, (2) reaction of 2-bromo-1-phenyl-ethanone with sodium cyanide, and (3) reduction of 3-oxo-3- phenyl-propionitrile with sodium borohydride. Hydrolysis of 3-oxo-3-phenylpropionitrile was carried out under acid and basic conditions. Step (1) was carried out at ≤ 2°C for 3 hours. The product was recrystallized in methanol and it gave 2-bromo-1-phenyl-ethanone in 71.77% yield. Step (2) was carried out at 40°C for 3 hours with and without catalyst to yield 3-oxo-3-phenyl-propionitrile with 100% purity. Reaction without catalyst yielded 18.00% yield. Reaction with tween 80 as catalyst yielded 58.05% yield. Step (3) was carried out at room temperature, 45-48°C, and 78-80°C respectively for 2 hours, 1 and 3 hours, and 3 hours. Reaction at room temperature for 2 hours yielded a mixture of products which were difficult to be identified. Reaction at 45- 48°C for 1 hours yielded 3-hydroxy-3-phenyl-propionitrile in 39.31% purity and 34.82% yield. Reaction for 3 hours yielded 3-hydroxy-3-phenyl-propionitrile in 22.31% purity and 19.60% yield. Reaction at 78-80°C yielded a mixture of products which were difficult to be identified. Hydrolysis of 3-oxo-3-phenylpropionitrile in acid condition was carried out at 40-45°C and 110-115°C. Hydrolysis at 40-45°C yielded a product that underwent decarboxylation to give acetophenone and hydrolysis at 110-115°C gave the same product. Hydrolysis in basic condition yielded a mixture of product which were difficult to be identified. Identification of the products were carried out by means of infrared (IR) spectroscopy, proton nuclear magnetic resonance (1H-NMR), and gas chromatography-mass spectroscopy (GC-MS).

Kata Kunci : Senyawa Flavon,Senyawa 8,aminoflavon