5-Methyl-2-(propan-2-yl)cyclohexyl benzoate → Menthol

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Reaction Steps

Benzoylation reaction was conducted to a menthol wherein the scandium (III) pentafluorophenylbis(triflyl)methide obtained from Examples 13 and 14 was used as a Lewis acid catalyst (Chemical formula 38). 1-menthol (0.18 g, 1 mmol) and benzoic anhydride (0.34 g, 1.5 mmol) were reacted while stirring in acetonitrile (4.8 mL) at 26° C. for 1 day, under the presence of the scandium (III) pentafluorophenylbis(triflyl)methide as 1 mol % of Lewis acid catalyst. Two to 3 drops of triethylamine was added to stop the reaction, the solution was added with 5 mL water, then concentrated and dried, and the menthyl benzoate produced was extracted with diethylether. The organic phase was analyzed with 1HNMR and it was found that the menthyl benzoate showed a high yield of 79%. The same reaction as mentioned above was conducted, except for the use of scandium (III) triflate [Sc(OTf)3] as a conventionally known Lewis acid catalyst, instead of the scandium (III) pentafluorophenylbis(triflyl)methide mentioned above. The yield of menthyl benzoate was only 48%. Based on these results, it was found out that the catalytic activity of the scandium (III) pentafluorophenylbis(triflyl)methide of the present invention is much more higher compared to that of the existing Lewis acid catalysts.

Provenance & Evidence