Diethyl Carbonate → Ethyl 2-(2-chloropyridin-4-yl)acetate

A solution of LDA (2.0 M in THF, 809 mL, 1.62 mol) was added dropwise over 3 hr to a stirred solution of 2-chloropicoline (43) (59.1 mL, 674 mmol) in THF (500 mL) at −78° C. The reaction mixture was stirred for a further 15 min and then diethylcarbonate (106 mL, 876 mmol) was added in a single portion. After 10 min the reaction mixture was allowed to warm to 0° C., was stirred at this temperature for 20 min and then a saturated aqueous solution of NH4Cl (800 mL) was added. The mixture was extracted with ether and the organic phase was washed with water, dried (MgSO4), and evaporated in vacuo to give a dark oil, (˜200 g) which was purified in three batches by flash column chromatography (SiO2, 330 g, 5-20% EtOAc in isohexane, gradient elution) to give the title compound (44) (72 g, 51%): m/z 200 (M+H)+ (ES+)

1. waitAfter 10 min the reaction mixture was allowed
2. stirringwas stirred at this temperature for 20 min
3. extractionThe mixture was extracted with ether
4. washthe organic phase was washed with water
5. dry with materialdried (MgSO4)
6. customevaporated in vacuo
7. customto give a dark oil, (˜200 g) which
8. customwas purified in three batches by flash column chromatography (SiO2, 330 g, 5-20% EtOAc in isohexane, gradient elution)

ORDレコード

ord-0f61ded08b3d4370850ce6d0314d77c6

出典データセット

uspto-grants-2012_10

DOI

10.6084/m9.figshare.5104873.v1

特許番号

US08299073B2