Manufacturing Process

11.1 parts of 8-hydroxy-quinaldine are dissolved in 140 parts of formic acid. Chlorine is introduced into this solution under cooling, until the increase in weight corresponds to the required quantity of chlorine and a test of the chlorination mixtures gives no more dyestuff formation with diazo-benzene in an acetic acid solutionWhen the chlorination is complete, the reaction mixture is poured into 1,000 parts of water and treated with a dilute sodium bisulfite solution, until no more reaction may be observed with starch potassium iodide paper. Thereby the 5,7-dichloro-8-hydroxy-quinaldine separates out in form of a weakly yellowish colored precipitate. The same is filtered off and thoroughly washed with water.After drying, 15 parts of 5,7-dichloro-8-hydroxy-quinaldine melting at 111°C to 112°C are obtained. When recrystallized from alcohol, the product is obtained in voluminous, slightly yellowish needles having the melting point of 111.5°C to 112°C.

Therapeutic Function

Antibacterial

Purification Methods

Crystallise it from EtOH. [Beilstein 21/3 V 346.]

Definition

ChEBI: A monohydroxyquinoline that is quinolin-8-ol which is substituted by a methyl group at position 2 and by chlorine at positions 5 and 7. An antifungal and antibacterial, it was formerly used for topical treatment of skin conditions and vaginal infections.