ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

KI-catalysed synthesis of 4-methylcatechol dimethylacetate and fragrant compound Calone 1951®

Ya-Zheng Zhang, Qian Yang, Shao-Jian Huang, Zi-Ping Luo, Wen-Ping Li, and Li-Chun Dong

School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 400044, China

E-mail: lcdong72@cqu.edu.cn

Abstract: Synthesis of the fragrant compound Calone 1951® from 4-methyl catechol and methyl bromoacetate entails three successive reactions: the Williamson reaction, Dieckmann condensation, and hydrolysis-decarboxylation reaction. In this paper, the synthesis of 4-methylcatechol dimethylacetate (MCDA) via the Williamson reaction by adding KI as catalyst was investigated. It was found that the addition of an appropriate amount of KI can significantly increase the product yield due to generation of methyl iodoacetate via the reaction between KI and methyl bromoacetate. The synthesised MCDA as well as Calone 1951® were first characterised by melting points, HPLC, IR, and NMR analyses. Next, the effect of the key operating factors on MCDA synthesis by the Williamson reaction was investigated and the optimum operating conditions were obtained via a group of orthogonal experiments. The verification experiments demonstrated that, under the optimum operating conditions, the MCDA yield could be increased from 78.5 % to 95.4 % by the addition of an appropriate amount of KI; the corresponding yield of Calone 1951® increased to 68 %.

Keywords: 4-methylcatechol dimethylacetate – MCDA – KI – catalysis – Calone1951® synthesis – synthesis process

Full paper is available at www.springerlink.com.

DOI: 10.2478/s11696-013-0359-z

Chemical Papers 67 (6) 586–593 (2013)