Sodium Sulfate → 6-[(4S)-4-{[3-(7-methoxy-2-oxoquinoxalin-1(2H)-yl)propyl]amino}-2-oxopyrrolidin-1-yl]-2H-1,4-benzoxazin-3(4H)-one

Participants

Reaction Steps

6-[(4S)-4-Amino-2-oxopyrrolidin-1-yl]-2H-1,4-benzoxazin-3(4H)-one (330 mg, 1.21 mmol) and 3-(7-methoxy-2-oxoquinoxalin-1(2H)-yl)propanal (Reference Example 8; 281 mg, 1.21 mmol) were dissolved in N,N-dimethylformamide (8.8 ml). Sodium sulfate (1.4 g) was added to this solution and the mixture was stirred at room temperature for 5.5 hours. Sodium triacetoxyborohydride (386 mg, 1.82 mmol) was added to the reaction solution and the mixture was stirred at room temperature for 2 days. After completion of the reaction, dichloromethane and a saturated sodium hydrogen carbonate aqueous solution were added to the reaction solution and the organic layer was separated. The organic layer was washed with water (3×) and saturated sodium chloride solution, dried over anhydrous magnesium sulfate and the solvent was removed under reduced pressure. The obtained residue was purified by flash column chromatography (chloroform/methanol) to yield 324 mg (58%) of the title compound in the form of light brown foamy crystals.

Provenance & Evidence