The systhesis of 4-Hidroxy-3-methoxybenzyl-2',4'-dihidroxyphenyl ketone from vanillin

LERREICK, Reinner Ishaq, Dr. Bambang Purwono, M.Sc

2008 | Tesis | S2 Ilmu Kimia

Telah dilakukan sintesis senyawa 4-hidroksi-3-metoksibenzil-2′,4′- dihidroksifenil keton dari vanilin. Senyawa ini merupakan salah satu senyawa antara yang sangat penting dalam sintesis senyawa isoflavon khususnya senyawa 3′- metoksidadzein. Vanillin digunakan sebagai bahan baku karena senyawa ini mudah dan murah terdapat di Indonesia. Sintesis dilakukan melalui empat tahap reaksi berkelanjutan yaitu reaksi reduksi vanillin menggunakan NaBH4, reaksi halogenasi vanillil alkohol menggunakan PBr3 yang diikuti reaksi nitrilisasi menggunakan KCN dalam sistem transfer fasa, reaksi hidrolisis asam senyawa vanillil sianida dan reaksi asilasi Friedel- Craft senyawa 4-hidroksi-3-metoksibenzil karboksilat menggunakan resorsinol dengan katalis asam Lewis. Gugus-gugus substituen pada vanillin tidak mempengaruhi sintesis 4- hidroksi-3-metoksibenzil-2′,4′-dihidroksifenil keton. Produk-produk sintesis yang diperoleh yaitu vanilil alkohol sebesar 83%, vanilil sianida sebesar 36% dan 4- hidroksi-3-metoksibenzil karboksilat sebesar 92%. Produk akhir berupa 74% senyawa 4-hidroksi-3-metoksibenzil-2′,4′-dihidroksifenil keton.

Synthesis of 4-hydroxy-3-methoxybenzyl-2′,4-dihydroxyphenyl ketone, an intermediate compound of synthesis of 3’-methoxydaidzein from vanillin has been done. This synthesis was aimed to diversify the utilization of Indonesian cheap raw material i.e. vanillin becoming high economy products such as drugs where daidzein has been developed as medicine and molecular model for synthesis new more active drugs. The synthesis was carried out by series of reaction i.e. hydride reduction of vanillin using NaBH4, halogenations of vanillyl alcohol with PBr3 followed by nitrilization of using KCN, acid hydrolysis of vanillyl cianyde and Friedel-Craft acylation of 4-hydroxy-3-methoxybenzyl carboxylate with resorcinol in the presence of AlCl3 as Lewis acid. There were no significant influences from vanillin substituen groups to synthesis of 4-hydroxy-3-methoxybenzyl-2′,4′-dihydroxyphenyl ketone. Yields of synthesis were 83 % of vanillyl alcohol, 36 % of vanillyl cyanide and 92 % of 4- hydroxy-3-methoxybenzyl carboxylate. The final product was 74 % yield of 4- hydroxy-3-methoxybenzyl-2′,4′-dihydroxyphenyl ketone.

Kata Kunci : Vanilin,4,hidroksi,3,metoksibenzil,2',4',dihidroksifenil keton,Senyawa antara,3',metoksidaidzein, vanillin, 4-hydroxy-3-methoxybenzyl-2′,4′-dihydroxyphenyl ketone, intermediate compound, 3′-methoxydaidzein