Sodium Bicarbonate → (+/-)-6-(1,3-Dioxo-1,3-dihydro-isoindol-2-yl)-5-methoxy-2,3,6,7-tetrahydro-[1,4]diazepine-1-carboxylic acid ethyl ester

Participants

Reaction Steps

To a solution of 45.00 g (135.82 mmol) of (+/−)-6-(1,3-dioxo-1,3-dihydro-isoindol-2-yl)-5-oxo-[1,4]diazepane-1-carboxylic acid ethyl ester in 339 mL of anhydrous dichloromethane was added 22.09 g (149.40 mmol) of trimethyloxonium tetrafluoroborate. The resulting mixture was stirred at room temperature for 12 h. The mixture was hydrolyzed with a saturated aqueous solution of sodium hydrogen carbonate, extracted with dichloromethane, dried over sodium sulfate and the solvent was evaporated to afford 46.90 g (99%) of pure product as yellow oil. The compound was used as such in the next step.

Provenance & Evidence