反应详情

9 g (88 mmol) of the (S)-(+)-2-methylbutyric acid obtained by the method of the above Referential Example 1 was mixed with 20.24 g of 99.5% by vol. ethanol containing 0.4 g of conc. sulfuric acid and heated under reflux for 4 hours. After the completion of the reaction, the mixture was cooled to room temperature and poured into 150 ml of a saturated aqueous solution of sodium chloride. The oily layer was extracted with n-hexane and thus separated from the aqueous layer. Then it was further washed with a saturated aqueous solution of sodium chloride twice and dehydrated over calcium chloride. After distilling off the n-hexane under atmospheric pressure, the temperature was further elevated. Thus 9.3 g of (S)-(+)-ethyl 2-methylbutyrate (boiling point: 135° C./760 mmHg) was obtained (yield: 81.3%).

1. temperatureheated
2. temperatureunder reflux for 4 hours
3. customAfter the completion of the reaction
4. extractionThe oily layer was extracted with n-hexane
5. customthus separated from the aqueous layer
6. washThen it was further washed with a saturated aqueous solution of sodium chloride twice
7. distillationAfter distilling off the n-hexane under atmospheric pressure