Triethylamine → HCID 86732765, compound

Participants

Reaction Steps

To a suspension of 5-chloro-1-ethyl-6,7-bis((4-methoxybenzyl)oxy)-4-oxo-1,4-dihydroquinoline-3-carboxylic acid (24 g, 41.7 mmol) in Tetrahydrofuran (THF) (450 mL) was added triethylamine (8.71 mL, 62.5 mmol), followed by careful addition of isobutyl chloroformate (7.66 mL, 58.4 mmol). The resulting mixture was stirred at r.t. for 2.5 h. Then the mixture was cooled down to −40° C. and a solution of DIBAL-H (69.5 mL, 104 mmol) in toluene (1.5 M) was added. The mixture was stirred at the same temperature for 3.5 h. After completion, the reaction was quenched with sat. NH4Cl (aq.), warmed up to r.t., diluted with sat. NH4Cl (aq.), filtered through Celite to remove gummy precipitate, and extracted with dichloromethane twice. The combined organic extracts were then saturated with brine and then dried over sodium sulfate, filtered and the resulting filtrate was concentrated in vacuo to afford 5-chloro-1-ethyl-3-(hydroxymethyl)-6,7-bis((4-methoxybenzyl)oxy)quinolin-4(1H)-one (19 g, 30.9 mmol, 74.2% yield) as a yellow solid, which was used in the next oxidation step. LCMS: (M+H)+: 510.0.

Provenance & Evidence