Sulfuric Acid → 2,3-Di(propan-2-yl)butanedioic acid

Temperature

160 °C

10 ml of 95% concentrated sulfuric acid was slowly added dropwise into 5 ml of water, and the mixture was cooled to room temperature, to obtain a sulfuric acid solution. The prepared sulfuric acid solution was added into a three-necked flask containing 0.22 g of diethyl 2,3-diisopropyl-2-cyanosuccinate, and the reaction mixture was stirred at an oil-bath temperature of 160° C. for 16 h. Upon the completion of the reaction, the reaction mixture was cooled to room temperature, diluted with 30 ml of water, and cooled to room temperature again. The reaction mixture was extracted with anhydrous diethyl ether, and the solvent was removed from the extract liquor, to afford a mixture of white solids and oily liquid. This mixture was dissolved in 10 ml of 10% aqueous KOH solution, and the resultant solution was stirred at 50° C. for 45 min. The reaction mixture was extracted with diethyl ether, and the organic phase was discarded. The aqueous phase was acidified with concentrated hydrochloric acid, whereby white precipitates formed. The precipitates were filtered and dried, to afford the product, 2,3-diisopropyl succinic acid (yield: 60%).

1. customUpon the completion of the reaction
2. temperaturethe reaction mixture was cooled to room temperature
3. temperaturecooled to room temperature again
4. extractionThe reaction mixture was extracted with anhydrous diethyl ether
5. customthe solvent was removed from the extract liquor
6. customto afford
7. additiona mixture of white solids and oily liquid
8. extractionThe reaction mixture was extracted with diethyl ether
9. customwhite precipitates
10. customformed
11. filtrationThe precipitates were filtered
12. customdried

ORD record

ord-239a02d860134e4f83908748a847d526

Source dataset

uspto-grants-2014_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08669392B2