• Journal of the Korean Chemical Society
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• v.55 no.4
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• pp.685-690
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• 2011

Novel acidic ionic liquids, 1-(${\omega}$-sulfonicacid)propyl-3-methylimidazolium bromide ([$HSO_3$pmim]Br)and 1-(${\omega}$-sulfonicacid)butyl-3-methylimidazolium bromide ([$HSO_3$bmim]Br), were prepared and used as brominating agents, catalysts and solvents in the synthesis of 1,7-dibromoheptane, respectively. 1,7-dibromoheptan with a yield of 95% was obtained at $100^{\circ}C$ for 2 h by simple phase separation. The acidic ionic liquid [$HSO_3$pmim]Br was recycled for 5 times and the yield of 1,7-dibromoheptane did not decrease remarkably, which indicates that catalysts still maintain good selectivity and activity after recycling. The structure of the acidic ionic liquid [$HSO_3$pmim]Br was characterized with IR, and it was found that [$HSO_3$pmim]Br had stronger acidity than other ionic liquid.

• Journal of the Korean Chemical Society
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• v.40 no.4
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• pp.243-248
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• 1996

New routes have been developed for the practical syntheses of dl-Muscone(1) employing cyclopentadecanone(2) as the starting material. In this experiment, addition of bromine to cyclopentadecanone in dried E. Ether solution with a trace of $AlCl_3$ as the catalyst were produced 2-bromocyclopentadecanone(3). This process was enhanced formation of regioselective enolate anion at $C_2$ position. 2-Bromocyclopentadecanone was put into $Li_2CO_3$-LiBr-DMF solution at 140∼150$^{\circ}C$, were produced trans- and cis-2-cyclopentadecen-1-one(4) mixture. Other by-products were reduced by control of reaction temperature and time. Trans- and cis-2-cyclopentadecen-1-one(4) mixture was directly put into dried E. Ether solvent and induce to react dropwise with $CH_3MgBr-Cu_2Cl_2$ complex, all of them got into 1,4-addition, dl-Muscone (1) was formed as the result. Conculsion, through three steps procedure from cyclopentadecanone(2) to dl-Muscone(1), the pure dl-Muscone was obtained with the high proportion of 85%, and synthetic cost was able to be much lower than any other conventional methods as there were no chemical separating steps.