Hydrochloric Acid → 4-Bromoisoquinolin-5-amine

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Reaction Steps

100 ml of concentrated hydrochloric acid are added to a suspension of 16 g of the compound obtained in Step 1 in 55 ml of ethanol. The mixture is cooled with ice and stirred whilst a solution of 62.6 g of SnCl2.2H2O in 100 ml of ethanol is being introduced and then for a further 3 hours. After removal of the solvent by evaporation, the residue is diluted with 140 ml of ice-cold water and rendered basic with 2N sodium hydroxide solution. The resulting aqueous phase is extracted 3 times with 350 ml of methylene chloride each time. The combined organic phases are dried over MgSO4 and evaporated. The residue is purified by flash chromatography (CH2Cl2/MeOH: 98/2) to yield the expected product.

Provenance & Evidence