反应详情

3-(3-bromo-5-hydroxy-7-methoxy-5H-chromeno[2,3-b]pyridin-5-yl)-2,2-difluoropropanamide (0.120 g, 0.289 mmol) was added to a saturated solution of ammonium acetate (2.228 g, 28.9 mmol) in 2-propanol (20 mL) and the mixture was heated to reflux. After 2.5 hours the reaction was allowed to cool to rt and the 2-propanol was removed in vacuo. The derived residue was partitioned between CH2Cl2 (50 mL) and water (50 mL). The layers were separated and the aqueous layer was extracted with CH2Cl2 (3×25 mL) and EtOAc (3×25 mL). The combined organic layers were washed with saturated sodium bicarbonate, water, brine, dried over sodium sulfate, and concentrated. The product was precipitated from 1:1 chloroform and diethyl ether to afford 3-bromo-4′,4′-difluoro-7-methoxyspiro[chromeno[2,3-b]pyridine-5,2′-pyrrolidin]-5′-one as a gold solid. MS m/z=397.1 [M+H].

1. temperaturethe mixture was heated to reflux
2. customthe 2-propanol was removed in vacuo
3. customThe derived residue was partitioned between CH2Cl2 (50 mL) and water (50 mL)
4. customThe layers were separated
5. extractionthe aqueous layer was extracted with CH2Cl2 (3×25 mL) and EtOAc (3×25 mL)
6. washThe combined organic layers were washed with saturated sodium bicarbonate, water, brine
7. dry with materialdried over sodium sulfate
8. concentrationconcentrated
9. customThe product was precipitated from 1:1 chloroform and diethyl ether