1-Bromo-3-chloropropane → 7-(3-Chloropropoxy)-1-ethyl-3,3,5-trimethyl-1,5-dihydrobenzo[b][1,4]diazepine-2,4-dione

Participants

Reaction Conditions

Reaction Steps

1-Ethyl-7-hydroxy-3,3,5-trimethyl-1,5-dihydrobenzo[b][1,4]diazepine-2,4-dione (1.85 g, 7.1 mmol) and potassium carbonate (1.2 g, 8.5 mmol) were added to 50% water-containing acetonitrile (40 ml), and dissolved by heating to 70° C. 1-Bromo-3-chloropropane (2.1 ml, 21 mmol) was added thereto, and heating was conducted under reflux for 6 hours. The reaction mixture was cooled to room temperature. Water was added, and extraction with ethyl acetate was performed. The organic layer was dried over sodium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (n-hexane:ethyl acetate=2:1→1:1). The purified product was concentrated to dryness under reduced pressure to thereby obtain 2.18 g (yield: 91%) of 7-(3-chloropropoxy)-1-ethyl-3,3,5-trimethyl-1,5-dihydrobenzo[b][1,4]diazepine-2,4-dione as a colorless oil.

Provenance & Evidence