Sodium ethoxide → HCID 68675473, compound

Participants

Reaction Steps

Palladium carbon (10%, 1.1 g) was added to an ethanol solution (250 ml) of ethyl N-ethyl-N-(5-methoxy-2-nitrophenyl)malonamate (21.05 g, 67.8 mmol), and cooled in an ice water bath. Catalytic reduction was conducted at about room temperature. Celite filtration was conducted to remove the catalyst, and the filtrate was concentrated under reduced pressure. The residue was dissolved in tetrahydrofuran (THF) (200 ml). Sodium ethoxide (6.9 g, 102 mmol) was added thereto, and then heating was conducted under reflux for 15 minutes. The reaction mixture was cooled to room temperature, and the precipitated insoluble matter was collected by filtration. The filtrate was concentrated under reduced pressure. Water was added to the residue and the collected insoluble matter, and the mixture was neutralized with hydrochloric acid. Extraction with ethyl acetate was then performed. The organic layer was washed with a saturated sodium chloride aqueous solution, dried over anhydrous sodium sulfate, and concentrated under reduced pressure. The residue was recrystallized from ethanol to thereby obtain 7.9 g (yield: 50%) of 1-ethyl-8-methoxy-1,5-dihydrobenzo[b][1,4]diazepine-2,4-dione as a white powder. The mother liquor was then concentrated, and the residue was purified using a silica gel flash column (n-hexane:ethyl acetate=1:1→0:1) to thereby obtain 2.9 g of object compound.

Provenance & Evidence