1,4-Dichlorobenzene → 4-(5-Hexenyl)-1-chlorobenzene

Participants

Reaction Conditions

Reaction Steps

A solution containing 294 g (2 mol) of 1,4-dichlorobenzene in 500 ml of anhydrous tetrahydrofuran was added dropwise over a period of about 110 minutes under nitrogen at 80° C. to a stirred suspension containing 48.6 g (2.0 mol) of magnesium turnings. The mixture was subsequently heated for 2 hours at 80°-84° C., then decanted from the excess magnesium, and the resultant solution of the Grignard compound was added dropwise over a period of 30 minutes at 80° C. to a stirred solution containing 194 g (1.8 mol) of 6-bromo-1-hexene (Fluka GmbH, 7910 Neu-Ulm) in 200 ml of tetrahydrofuran. The mixture was then stirred for 4 hours at 80° C. and then poured onto ice. After acidification with hydrochlcric acid, the mixture was extracted three times with a 1:1 mixture of diethyl ether/methyl tert-butyl ether, and the ether fractions were stirred thoroughly with activated charcoal and dried over sodium sulfate. The filtrate was evaporated, and the residue was fractionated. At a pressure of 13 hPa and a temperature of 116°-118° C., 156 g (corresponding to a yield of 40% of theory) of 4-(5-hexenyl)-1-chlorobenzene were obtained. 4-(8-Nonenyl)-1-chlorobenzene (b.p. 87° C. at 0.3 hPa), for example, can also be prepared in the same way.

Provenance & Evidence