1-Ethyl-7-benzyloxy-3,3,5-trimethyl-1,5-dihydrobenzo[b][1,4]diazepine-2,4-dione → 1-Ethyl-7-hydroxy-3,3,5-trimethyl-1,5-dihydrobenzo[b][1,4]diazepine-2,4-dione

Participants

Reaction Steps

10% palladium carbon (1.66 g, water content: 54.8%) was added to an ethanol (150 mL) solution of 1-ethyl-7-benzyloxy-3,3,5-trimethyl-1,5-dihydrobenzo[b][1,4]diazepine-2,4-dione (15.0 g, 42.6 mmol), and catalytic hydrogenation reaction was performed at 40-50° C., at 3 atm. The reaction solution was filtered to remove a catalyst, and ethanol was distilled off. Methanol (105 mL) and water (105 mL) were added to the resulting residue, and the mixture was heated while stirring. After the dissolution was confirmed, stirring under ice cooling was conducted for 1 hour, and precipitated crystals were collected by filtration. The resulting crystals were washed with 50% methanol (30 mL), and dried at 60° C., thereby obtaining 10.7 g of a white, powdery target compound (yield: 96%).

Provenance & Evidence