Sodium triacetoxyborohydride → 6-(4-{[4-(7-Methoxy-2-oxoquinoxalin-1(2H)-yl)butyl]amino}-2-oxopyrrolidin-1-yl)-2H-1,4-benzoxazin-3(4H)-one

Participants

Reaction Conditions

Reaction Steps

6-(4-Amino-2-oxopyrrolidin-1-yl)-2H-1,4-benzoxazin-3(4H)-one (56.9 mg, 0.230 mmol) and 4-(7-methoxy-2-oxoquinoxalin-1(2H)-yl)butanal (Reference Example 3; 56.6 mg, 0.230 mmol) were dissolved in chloroform/methanol (10:1, v/v, 3 ml), molecular sieve 3 A (powder 700 mg) was further added, and the mixture was stirred at 60° C. for 4.5 hours. After cooling, sodium triacetoxyborohydride (154 mg, 0.69 mmol) was added to the reaction solution and the mixture was stirred at room temperature for 1.5 hours. After completion of the reaction, the molecular sieve was removed by filtration and a saturated sodium hydrogen carbonate aqueous solution was added to the filtrate and stirred. After separating the organic layer, the aqueous layer was extracted twice with chloroform/methanol (10:1, v/v) and combined with the organic layer. The organic layer was dried over anhydrous magnesium sulfate and the solvent was removed under reduced pressure. The obtained residue was purified by silica gel column chromatography (chloroform/methanol) to yield 92.6 mg (84%) of the title compound in the form of a colorless solid.

Provenance & Evidence