2,6-Dimethoxypyridine → HCID 57517884, compound

Temperature

10 °C

To a stirred solution of 2,6-dimethoxypyridine (50 mmol, 6.61 mL) in THF (100 mL) was added slowly a 1.6 M solution of n-butyllithium in hexanes (55 mmol, 34.4 mL) at −78° C. The mixture was allowed to warm slowly to 10° C. and kept at this temperature for 30 min. The reaction mixture was re-cooled to −78° C. and a slurry of 5-chloroisatin (20 mmol, 3.63 g) in THF (150 mL) was added portionwise, keeping the temperature below −60° C. The reaction was allowed to come to room temperature. The mixture was quenched with 10% aqueous ammonium chloride solution and extracted several times with ethyl acetate. The combined organic layers were washed with water, dried over magnesium sulfate and evaporated in vacuo. Recrystallization from ethyl acetate yielded 4.56 g (71%) of the desired intermediate as a white crystalline solid (71%).

1. temperatureThe reaction mixture was re-cooled to −78° C.
2. customthe temperature below −60° C
3. customto come to room temperature
4. customThe mixture was quenched with 10% aqueous ammonium chloride solution
5. extractionextracted several times with ethyl acetate
6. washThe combined organic layers were washed with water
7. dry with materialdried over magnesium sulfate
8. customevaporated in vacuo
9. customRecrystallization from ethyl acetate

ORD record

ord-19d161aa560b4efb9668ce07250f2266

Source dataset

uspto-grants-2013_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08580842B2