Isoquinoline → 5-Bromoisoquinoline

Participants

Reaction Conditions

Reaction Steps

The apparatus consisted of a 500 mL three-necked flask equipped with a condenser, dropping funnel and a stirrer terminating in a stiff, crescent-shaped Teflon polytetrafluroethylene paddle. To isoquinoline (57.6 g, 447 mmol) in the flask was added AlCl3 (123 g, 920 mmol). The mixture was heated to 75-85° C. Bromine (48.0 g, 300 mmol) was added using a dropping funnel over a period of 4 hours. The resulting mixture was stirred for one hour at 75° C. The almost black mixture was poured into a vigorously hand-stirred cracked ice. The cold mixture was treated with sodium hydroxide solution (10N) to dissolve all the aluminum salts as sodium aluminate and the oily layer was extracted with ether. After being dried with Na2SO4 and concentrated, the ether extract was distilled at about 0.3 mm. A white solid (16.3 g, 78 mmol) from a fraction of about 1.25° C. was obtained (26% yield). The product was further purified by recrystallization (pentane or hexanes): mp 80-81° C.;

Provenance & Evidence