Hydrochloric Acid → 4-Bromo-5-isoquinolinesulfonyl chloride

Participants

Reaction Conditions

Reaction Steps

4-Bromo-5-isoquinolinesulphonyl chloride may be obtained in the following manner: a solution of 5-amino-4-bromoisoquinoline (4.46 g) in hydrochloric acid (d=1.19) (44 cc) is cooled to -5° C. and then treated with a solution of sodium nitrite (1.93 g) in water (10 cc). The reaction mixture is stirred for 1 hour at 0° C. The solution obtained is poured into a saturated solution of sulphur dioxide in acetic acid (48 cc) to which a solution of cuprous chloride (0.65 g) in water (5.6 cc) has been added. The reaction mixture is stirred until the gaseous evolution has ceased and is then extracted with dichloromethane (2×100 cc). The organic phases are combined, washed with water, dried over magnesium sulphate and concentrated. 4-Bromo-5-isoquinolinesulphonyl chloride (5.6 g) is obtained in the form of a yellow solid, which is used without further treatment in the subsequent syntheses.

Provenance & Evidence