反应详情

To a stirred solution of ethyl 4-amino-6-methylthieno[2,3-b]pyridine-5-carboxylate (Description 65) (1 g, 4.23 mmol) in acetic acid (3 mL) was added bromine (0.65 mL, 12.70 mmol) and the resulting mixture stirred at RT overnight (ca. 18 h). The reaction was quenched by pouring the reaction mixture into water and the aqueous solution was basified with NaOH (5M) and diluted with ethyl acetate (30 mL). The organic layer was separated and the aqueous layer was re-extracted with ethyl acetate (20 mL×3). The combined organics were washed with saturated sodium thiosulphate solution, dried and concentrated. Purification by chromatography on silica, eluting with a gradient of 0-30% ethyl acetate in DCM afforded the title compound (1.16 g). LCMS (A) m/z: 315/317 [M+1]+, Rt 0.95 min (acidic).

1. customThe reaction was quenched
2. additionby pouring the reaction mixture into water
3. additiondiluted with ethyl acetate (30 mL)
4. customThe organic layer was separated
5. extractionthe aqueous layer was re-extracted with ethyl acetate (20 mL×3)
6. washThe combined organics were washed with saturated sodium thiosulphate solution
7. customdried
8. concentrationconcentrated
9. customPurification by chromatography on silica
10. washeluting with a gradient of 0-30% ethyl acetate in DCM