反应详情

To a solution of crude 2-(2-oxo-2-pyridin-3-ylethyl)isoindole-1,3-dione (Preparation 97, 5.0 g, ˜19.0 mmol) in aqueous isopropanol (210 ml, water/IPA:1/6) was added sodium borohydride (10.2 g, 270 mmol) in 2 portions. The mixture was stirred at rt for 12 h before being carefully acidified (pH 2) with dilute hydrochloric acid (1M). After removal of the solvent the residue was taken up in destillated water (100 mL) and passed down a column filled with ion-exchange resin (Amberlite IR 120, H+-form, 300 g, eluent: 500 mL water then 1L of 2 M aqueous ammonia solution). Concentration of the alkaline fractions gave the title compound as a yellow oil. δH (d6 DMSO): 2.74, 2.85 (2H, 2m), 4.66 (11H, m), 5.15 (3H, br s), 7.36 (1H, dd), 7.75 (1H, m), 8.46 (1H, m), 8.56 (1H, m); m/z (ES+)=139.11 [M+H]+; RT=0.21 min.

1. customAfter removal of the solvent the residue
2. additionfilled with ion-exchange resin (Amberlite IR 120, H+-form, 300 g, eluent