Acetic Acid → 6-[(4R)-4-{[3-(7-Methoxy-2-oxoquinoxalin-1(2H)-yl)propyl]amino}-2-oxopyrrolidin-1-yl]-2H-pyrido[3,2-b][1,4]oxazin-3(4H)-one

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Reaction Steps

In N,N-dimethylformamide (5 ml) was dissolved 3-(7-methoxy-2-oxoquinoxalin-1(2H)-yl)propanal (Reference Example 8,200 mg, 0.86 mmol). 6-[(4R)-4-Amino-2-oxopyrrolidin-1-yl]-2H-pyrido[3,2-b][1,4]oxazin-3(4H)-one (synthesized using [(3R)-5-oxopyrrolidin-3-yl]carbamic acid tert-butyl ester synthesized with reference to WO2004/22536 in the same manner as in Reference Examples 20, 21 and 22; 262 mg, 1.03 mmol) was added thereto and subsequently acetic acid (65 mg, 1.12 mmol) was added. The obtained mixture was stirred at room temperature for 1 hour, cooled on ice and sodium triacetoxyborohydride (237 mg, 1.12 mmol) was added thereto. After stirring at room temperature for 2 hours, sodium hydrogen carbonate aqueous solution was added thereto and the mixture was extracted with ethyl acetate. The obtained organic layer was washed with water and a saturated sodium chloride solution, dried over anhydrous sodium sulfate and the solvent was removed under reduced pressure. The obtained crude product was purified by thin layer chromatography (dichloromethane/methanol) to yield 80 mg (20%) of the title compound.

Provenance & Evidence