反应详情

Aluminum chloride (6.93 g) is added in one portion to a solution of 2-ethoxycarbonyl-cyclopropane carboxylic acid chloride (4.17 g) and 1-phenyloctane (4.49 g) in methylene chloride (100 ml). After the initial exothermic reaction subsides, the mixture is heated under reflux for 16 hours. The mixture is cooled and poured into ice water (500 ml) containing conc. hydrochloric acid (50 ml). The product is extracted with ether (3×200 ml). The extract is dried over MgSO4 and then evaporated under reduced pressure. The residue is chromatographed on silica gel (hexane/ether) to provide ethyl 2-(4-n-octylbenzoyl)cyclopropane carboxylate as an oil (4.7 g). This ester is heated under reflux in aqueous 2N NaOH (36 ml) for 24 hours. The reaction mixture is diluted with water (100 ml), acidified and extracted with ether (3×50 ml). The extract is dried (MgSO4) and evaporated. The residue is crystallized from petroleum ether (40°-60°) to provide 2-(4-n-octylbenzoyl) cyclopropane carboxylic acid (1.88 g), m.p. 45°-47° C.

1. customAfter the initial exothermic reaction subsides
2. temperaturethe mixture is heated
3. temperatureunder reflux for 16 hours
4. temperatureThe mixture is cooled
5. extractionThe product is extracted with ether (3×200 ml)
6. dry with materialThe extract is dried over MgSO4
7. customevaporated under reduced pressure
8. customThe residue is chromatographed on silica gel (hexane/ether)