Diisobutylaluminum hydride → HCID 86732818, compound

Participants

Reaction Steps

To a suspension of 1-ethyl-7,8-bis((4-methoxybenzyl)oxy)-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (22 g, 44.9 mmol) in Tetrahydrofuran (THF) (300 mL) was added TEA (6.89 mL, 49.4 mmol) and isobutyl chloroformate (6.49 mL, 49.4 mmol). The resulting mixture was stirred at r.t. for 1 h. Then the mixture was cooled down to −78° C. and a solution of DIBAL-H (90 mL, 135 mmol) in toluene (1.5 M) was added. The mixture was stirred at the same temperature for 1.5 h, LCMS indicated completion of the reaction. The reaction was quenched with sat. NH4Cl (aq.), and subsequently warmed up to r.t. concentrated, diluted with sat. NH4Cl and extracted with dichloromethane twice. The organic phase was filtered through Celite to remove gummy precipitate, and was then washed with brine, dried over sodium sulfate, filtered and concentrated in vacuo to afford 1-ethyl-3-(hydroxymethyl)-7,8-bis((4-methoxybenzyl)oxy)quinolin-4(1H)-one (20 g, 23.55 mmol, 52.4% yield) as yellow solid, which was used in the next oxidation step without further purification. LCMS: (M+H)+: 476.3.

Provenance & Evidence