反应详情

温度

-70 °C

A 1.6 N solution of n-butyllithium in hexane was run dropwise into a solution, cooled to the region of -70° C., of 33 g (0.220 mol) of (RS)-2-phenylpropionic acid in 220 cm3 of tetrahydrofuran and of 44 cm3 of N,N'-tetramethylethylenediamine. After having stirred the reaction mixture for three hours at -70° C., the reaction mixture was returned to a temperature in the region of 20° C. and the solution obtained was run into a solution of 75 cm3 (0.55 mol) of ethyl oxalate in 110 cm3 of tetrahydrofuran, the temperature being maintained at -75° C., for 1 hour. The reaction mixture was hydrolysed with 800 cm3 of a saturated aqueous sodium hydrogencarbonate solution, extracted with three times 100 cm3 of ethyl acetate, washed with three times 50 cm3 of a normal aqueous hydrochloric acid solution, dried over sodium sulphate and concentrated under reduced pressure. 44 g (97%) of ethyl(RS)-2-oxo-3-phenylbutyrate were then obtained in the form of an orange oil, the characteristics of which were as follows:

1. customwas returned to a temperature in the region of 20° C.
2. customthe solution obtained
3. temperaturethe temperature being maintained at -75° C., for 1 hour
4. extractionextracted with three times 100 cm3 of ethyl acetate
5. washwashed with three times 50 cm3 of a normal aqueous hydrochloric acid solution
6. dry with materialdried over sodium sulphate
7. concentrationconcentrated under reduced pressure