反应详情

温度

25 °C

To a solution of 8.34 g (38.6 mmol) of diethyl isobutylmalonate in 35 mL of 95% EtOH was added a solution of 9.0 g (161 mmol) of KOH in 110 mL of 95% EtOH. The mixture was stirred at 25° C. for 16 hours and then at reflux for 1 hour. The mixture was cooled, diluted with water and extracted with CH3Cl. The aqueous layer was cooled to 0° C. and acidified to pH<1 with 30 mL of concentrated HCl, then it was extracted with CHCl3. The aqueous layer was further continuously extracted with CHCl3 overnight. The combined organic extracts were dried over anhydrous Na2SO4 and evaporated to afford 5.44 g (33.9 mmol, 88%) of isobutylmalonic acid as a solid which was essentially pure according to 1H NMR and which was used without further purification. Characteristic analytical data are as follows: mp 108°-110° C.; 1H NMR (300 MHz, CDCl3) δ3.52 (t, J=8 Hz, 1H), 1.84 (t, J=8 Hz, 2H), 1.66 (m, 1H), 0.94 (d, J-7 Hz, 6H); 13C NMR (75 MHz, CDCl3) δ175.6 (C=O), 49.7 (CH), 37.1 (CH2), 25.7 (CH), 21.7 (CH3).

1. temperatureat reflux for 1 hour
2. temperatureThe mixture was cooled
3. extractionextracted with CH3Cl
4. temperatureThe aqueous layer was cooled to 0° C.
5. extractionit was extracted with CHCl3
6. extractionThe aqueous layer was further continuously extracted with CHCl3 overnight
7. dry with materialThe combined organic extracts were dried over anhydrous Na2SO4
8. customevaporated