Difluoroacetic acid → 1,1-Difluoro-2-hexanone

Temperatur

-78 °C

To a 3 liter, three-neck, round bottom flask, equipped with a magnetic stirrer, a dropping funnel filled with 39.9 g. of difluoroacetic acid and 200 ml. of ether, and a rubber septum is added 1350 ml. of ether. After cooling in a dry ice-acetone bath under nitrogen, one mole of n-butyl lithium (2.2 M, hexane) is added via a double tip needle. The difluoroacetic acid solution is slowly added to the cooled n-butyl lithium solution via the dropping funnel over 3 hours. The thick mixture is stirred at -78° C. for one hour and then quenched by pouring into a mixture of one liter of 4 N hydrochloric acid and one liter of ice, divided into three flasks, with stirring. The organic layers are combined and washed with water and brine. The 1500 ml. of solution is distilled at atmospheric pressure in a water bath. After the forerun is collected, the residue is fractionally distilled giving 18.8 g. (b.p. 100°-110° C.) of product that is 75% real.

1. customTo a 3 liter, three-neck, round bottom flask, equipped with a magnetic stirrer, a dropping funnel
2. additionfilled with 39.9 g
3. temperatureAfter cooling in a dry ice-acetone bath under nitrogen
4. customquenched
5. additionby pouring into a mixture of one liter of 4 N hydrochloric acid and one liter of ice
6. stirringwith stirring
7. washwashed with water and brine
8. distillationof solution is distilled at atmospheric pressure in a water bath
9. customAfter the forerun is collected
10. distillationthe residue is fractionally distilled
11. customgiving 18.8 g

ORD-Eintrag

ord-2500b80f2f9e479d9868191f9358600f

Quelldatensatz

uspto-grants-1981_03

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US04254036