Phosphorus oxychloride → Ethyl 2-(2-chloropyridin-3-yl)acetate

A mixture of 1.56 g (8.6 mol) of 3-pyridineacetic acid ethyl ester 1-oxide (for preparation, see A. R. Katritzky, J. Chem. Soc., 1956, 2404) and 15 ml of phosphorous oxychloride was heated to 80° C. for 3 hours. After cooling, the solvent was evaporated and the residue was poured onto ice water and solid sodium bicarbonate was added until the pH was basic. The organic layer was extracted with ethyl acetate and the combined extracts were dried over sodium sulfate and evaporated to an oil which was purified by flash chromatography with an ethyl acetate-hexane (1:4-1:1) eluant. The fractions containing the less polar isomer (Rf 0.3, ethyl acetate-hexane (3:7)) were combined and evaporated to yield 584 mg (50%) of the title compound of this preparation as an oil. 1H NMR (CDCl3): δ 1.22 (3H, t, J=7), 3.76 (2H, s), 4.15 (2H, q, J=7), 7.11-7.21 (2H, m), 8.25-8.31 (1H, m).

1. customfor preparation
2. temperatureAfter cooling
3. customthe solvent was evaporated
4. additionthe residue was poured onto ice water and solid sodium bicarbonate
5. additionwas added until the pH
6. extractionThe organic layer was extracted with ethyl acetate
7. dry with materialthe combined extracts were dried over sodium sulfate
8. customevaporated to an oil which
9. customwas purified by flash chromatography with an ethyl acetate-hexane (1:4-1:1) eluant
10. additionThe fractions containing the less polar isomer (Rf 0.3, ethyl acetate-hexane (3:7))
11. customevaporated
12. customto yield

ORD 기록

ord-c6398db54f8d43fba5d136088495a66a

출처 데이터셋

uspto-grants-1998_08

DOI

10.6084/m9.figshare.5104873.v1

특허 번호

US05789408