Triethylamine → 2-(1,3-dioxo-1,3-dihydro-isoindol-2-yl)-ethanesulfonic acid 9-benzhydryloxy-7-(4-fluoro-benzyl)-8-oxo-7,8-dihydro-6H-pyrrolo[3,4-g]quinolin-5-yl ester

Participants

Reaction Steps

Triethylamine (50 μl), DMAP (catalytic amount) and 2-(1,3-dioxo-1,3-dihydro-isoindol-2-yl)-ethanesulfonyl chloride (27.4 mg, 0.10 mmol) were added to 0.034 mmol 45. The reaction mixture was stirred at room temperature for 18 hours under an inert atmosphere. The reaction was monitored by TLC (EtOAc/hexane 3/7) (Rf 44=0.5, Rf 45=0, Rf 268=0.4) and LC/MS. After completion of the reaction, the mixture was diluted with EtOAc (20 mL) and washed with 1N HCl, saturated NaHCO3 and brine. The organic phase was dried (MgSO4), filtered and concentrated in vacuo. The residue was purified by silica gel chromatography (ethylacetate/hexane—3/7) to afford 2-(1,3-dioxo-1,3-dihydro-isoindol-2-yl)-ethanesulfonic acid 9-benzhydryloxy-7-(4-fluoro-benzyl)-8-oxo-7,8-dihydro-6H-pyrrolo[3,4-g]quinolin-5-yl ester 268 (12.2 mg, 50%).

Provenance & Evidence