Sodium Hydroxide → 3,8-Dibromo-6-hydroxyquinoline

Participants

Reaction Conditions

Reaction Steps

6-Amino-3,8-dibromoquinoline (0.15 g) was suspended in phosphoric acid (75%, 11 ml) and heated in a sealed glass, tube at 180° C. for 72 hours. The mixture was allowed to cool to ambient temperature, diluted with ice (50 ml) and taken to pH 2 with aqueous sodium hydroxide (4M). The brown suspension that formed was extracted with ethyl acetate (twice), dried over magnesium sulphate then evaporated under reduced pressure to give 3,8-dibromo-6-hydroxyquinoline (M+−H 300, 2×Br) as a dark red solid that was used in the next stage without further purification, 1H NMR (d6 DMSO) δ: 7.14(1H, d); 7.60(1H, d); 8.52(1H, d); 8.71(1H, d). In a similar procedure to Step 3, 6-amino-3-bromoquinoline was converted to 3-bromo-6-hydroxyquinoline, brown solid, 1H NMR (d6 DMSO) δ: 7.19(1H, d); 7.40(1H, dd); 7.92(1H, d); 8.66(1H, s); 8.79(1H, s).

Provenance & Evidence