Water → 2-(1,2-Benzoxazol-3-yl)acetic acid

Beteiligte Stoffe

Reaktionsschritte

A mixture of hydroxylamine sulfate (344.0 g), water (904 ml) and a 25% aqueous sodium hydroxide solution (456 ml) is stirred, and thereto are added 4-hydroxycoumarin (168.0 g) and ethylenediaminetetraacetic acid disodium salt dihydrate (3.2 g), and the mixture is stirred with heating at 84° C.-86° C. for 4 hours. The reaction mixture is cooled, and thereto is added 1,2-dichloroethane (240 ml). The mixture is stirred, and the aqueous layer is collected. The pH value of the aqueous layer is adjusted to pH 1-2 with 25% sulfuric acid, and the precipitated crystals are collected by filtration, washed with water, and dried with air at 60° C. for 15 hours to give 1,2-benzisoxazole-3-acetic acid (170.4 g).

Herkunft & Nachweise