反応 #629353

反応方程式

ethyl oxalate

3-bromopyridine

butyl lithium

→

title product

3-pyridyl glyoxylic acid

溶媒

THF

THF

THF

反応条件

後処理

1. 1
   workup.DISSOLUTIONdissolved in 120 ml
2. 2
   その他into a stirred 0° C.
3. 3
   workup.STIRRINGThe solution was stirred at 0° C. for 45 minutes
4. 4
   その他quenched by addition of 50 ml
5. 5
   温度glacial acetic acid, warmed to room temperature
6. 6
   workup.ADDITIONpoured into 500 ml of water
7. 7
   抽出extracted with 2×500 ml ethyl acetate
8. 8
   洗浄The combined organic layers were washed with brine
9. 9
   乾燥dried (MgSO4)
10. 10
    ろ過filtered
11. 11
    濃縮concentrated in vacuo to a brown oil
12. 12
    その他chromatographed on silica gel
13. 13
    洗浄eluted with 1:2 ethyl acetate hexane
14. 14
    その他A viscous yellow oil was obtained

実験手順

10 g. (0.063 mol) of 3-bromopyridine in 80 ml. of dry THF was added dropwise to a -70° C. solution of butyl lithium (1.6M, 40.6 ml, 0.065 mol) dissolved in 120 ml. of dried THF over a 20 minute period. The resulting brown solution was stirred at -70° C. for 30 minutes and then transferred by nylon tubing under positive nitrogen pressure into a stirred 0° C. solution of ethyl oxalate (36.8 g, 0.25 mol) in 60 ml of dry THF. The solution was stirred at 0° C. for 45 minutes, quenched by addition of 50 ml. glacial acetic acid, warmed to room temperature and poured into 500 ml of water, adjusted to pH 7.0 with 750 ml saturated sodium bicarbonate and extracted with 2×500 ml ethyl acetate. The combined organic layers were washed with brine, dried (MgSO4), filtered and concentrated in vacuo to a brown oil; 24.7 g. This oil was flash chromatographed on silica gel eluted with 1:2 ethyl acetate hexane. A viscous yellow oil was obtained; 1.56 g, m/e 179, spectral data consistent with structure of title product.

出典