反应详情

温度

-78 °C

LDA was prepared by the addition of n-butyllithium (2.5 M in hexanes, 0.95 mL, 2.38 mmol) to a solution of diisopropylamine (0.345 mL, 2.42 mmol) in THF (5 mL) at −20° C. After 10 minutes, the solution was cooled to −78° C. 4-Chloro-3-iodo-pyridine (500 mg, 2.09 mmol) in THF (3 mL) was added dropwise, and the reaction stirred for 30 minutes Iodoethane (0.2 mL, 2.5 mmol) was added, and the reaction was stirred for 1 hour at −78° C., then 1 hour while warming to 0° C. The reaction was quenched with sat. NH4Cl, made basic with saturated NaHCO3, and extracted with ethyl acetate. Organics were washed with brine, dried over Na2SO4, and concentrated in vacuo. Purification by silica gel chromatography (20% ethyl acetate/hexanes) gave 429 mg (77%) of 4-chloro-3-ethyl-5-iodo-pyridine as a waxy white solid. 1H NMR (300 MHz, CDCl3) δ 8.78 (s, 1H), 8.33 (s, 1H), 2.83 (q, 2H, J=7.5 Hz), 1.26 (t, 3H, J=7.5 Hz). Anal. (C7H7ClIN) C, H, N.

1. additionwas added
2. temperature1 hour while warming to 0° C
3. customThe reaction was quenched with sat. NH4Cl
4. extractionextracted with ethyl acetate
5. washOrganics were washed with brine
6. dry with materialdried over Na2SO4
7. concentrationconcentrated in vacuo
8. customPurification by silica gel chromatography (20% ethyl acetate/hexanes)