抄録
Reaction of 1 part of 2-bromo-4-nitrophenol (III) with 1.5 parts of glacial acetic acid, 2.5 parts of glycerol, and 3 parts of conc. sulfuric acid by heating afforded a mixture of 5-bromo-6-hydroxyquinoline (II) and 6-hydroxy-7-bromoquinoline (I) in approx. 3:1 ratio. The use of conc. phosphoric acid in place of glacial acetic acid afforded a small amount of (I) alone. The same reaction with 1 part of 2, 6-dibromo-4-nitrophenol (VI) afforded 5, 7-dibromo-6-hydroxyquinoline (VII) and the use of 80% formic acid in place of the glacial acetic acid in this reaction chiefly gave (VII), accompanied with a small amount of (I). The use of conc. phosphoric acid in place of glacial acetic acid afforded (I) alone in a fairly high yield. These experimental results indicated that the synthesis of 6-hydroxy-7-bromoquinoline (I) alone and in a good yield can be effected by the modified Skraup reaction of 2, 6-dibromo-4-nitrophenol with conc. phosphoric acid, glycerol, and conc, sulfuric acid.
