1(2H)-Isoquinolinone → 5,6,7,8-Tetrahydroisoquinolin-1(2H)-one

Participants

Reaction Steps

60 g (413 mmol) of 2H-isoquinolin-1-one (=isocarbostyril) are dissolved in 1 l of glacial acetic acid and, after addition of 2.3 g (10 mmol) of platinum(IV) oxide, hydrogenated under 3 bar at RT until conversion is complete. This entailed changing the catalyst after 3 days and a further 5 days. The suspension is filtered, concentrated and again concentrated after addition of toluene. The crude product is recrystallized from 1.6 l of water. Long needles are filtered off, and the mother liquor is concentrated and dried and separated on silica gel. 36.8 g (60%) of a colorless oil are obtained.

Provenance & Evidence