反应详情

A solution of ethyl 1-tert-butyl-6,7-difluoro-1,4-dihydro-8-methoxy-4-oxoquinoline-3-carboxylate (4.00 g, 11.8 mmol) in CH2Cl2 (20 mL) and trifluoroacetic acid (4.0 mL) was stirred at 0° C. for 30 min. The mixture was concentrated in vacuo and poured into 500 mL of ice-water. The resulting precipitate was removed by filtration, washed with water and then dried to yield ethyl 6,7-difluoro-1,4-dihydro-8-methoxy-4-oxoquinoline-3-carboxylate (3.34 g, quant) as a colorless solid.

1. concentrationThe mixture was concentrated in vacuo
2. additionpoured into 500 mL of ice-water
3. customThe resulting precipitate was removed by filtration
4. washwashed with water
5. customdried