1-Bromoheptane → HCID 551435, compound

Participants

Reaction Conditions

Reaction Steps

Under an atmosphere of nitrogen the flask is charged with 121 g magnesium and 720 g tetrahydrofuran. The Grignard-reaction is started with 5 g bromo-heptane. Then, a solution of 908 g bromo-heptane in 1000 g toluene is added dropwise within 260 minutes under stirring. The reaction mixture is kept between 55 and 60° C. The resulting dark solution is cooled to 10° C. and a solution of 357 g crotonaldehyde in 500 g toluene is added dropwise within 105 minutes, during which the pot temperature is kept between 10 and 20° C. with an ice-water bath. The resulting grey-brown suspension is continued to stir for 20 minutes at max. 20° C. and then poured, under vigorous stirring, into a mixture of 2 kg ice and 1 l aqueous saturated ammonium chloride solution. The mixture is diluted with 4 l water and buffered with 300 ml acetic acid. The phases are separated. The organic layer is washed with 4 l and 2 l hot water. The organic phase is concentrated in vacuo to give 864 g crude product as a pale yellow oil. This is distilled at 0.1 mbar over a 10 cm-Raschig ring column. Fractions boiling between 85 and 90° C. were collected to give 709 g undec-2-en-4-ol.

Provenance & Evidence