Iodine → 1-iodoisoquinoline

Participants

Reaction Steps

A dry and argon flushed 10 mL flask, equipped with a magnetic stirrer and a septum, was charged with TMPMgCl LiCl (5 mL, 1.2 M in THF, 6.0 mmol). Isoquinoline (703 mg, 5.45 mmol) in THF (5 ml) was added dropwise at room temperature. During addition, the reaction mixture became red and the metalation was complete after 2 h (as checked by GC analysis of reaction aliquots quenched with a solution of I2 in THF, the conversion was more than 98%). A solution of I2 in THF (6 ml, 1 M in THF, 6.0 mmol) was slowly added at −20° C. The reaction mixture was quenched with sat. aqueous NH4Cl solution (10 mL). The aqueous phase was extracted with ether (4×10 mL), dried with Na2SO4 and concentrated in vacuo. The crude residue was purified by filter column chromatography (CH2Cl2/pentane) yielding 1-iodoisoquinoline (7a; 1.33 mg, 96%) as slightly yellow crystals (mp=74-76° C.).

Provenance & Evidence