反応 #1432

反応方程式

1-bromo-4-chlorobutane

cyclopentanecarboxylic acid

diisopropylamine

n-butyl lithium

→

lithium diisopropylamide

title product

1-(4-Chlorobutyl)cyclopentanecarboxylic acid

溶媒

tetrahydrofuran

tetrahydrofuran

tetrahydrofuran

反応条件

後処理

1. 1
   温度maintaining the temperature between -3° C.-1° C
2. 2
   workup.WAITAfter an additional 15 minutes at 0° C.
3. 3
   その他the bath was removed
4. 4
   workup.STIRRINGthe reaction stirred 15 minutes more
5. 5
   その他to rise to 11° C
6. 6
   その他rising to -66° C
7. 7
   workup.WAITAfter 16 hours
8. 8
   温度to warm to room temperature in situ
9. 9
   その他The reaction was quenched with methanol (10 ml.)
10. 10
    濃縮concentrated in vacuo
11. 11
    その他The residue was partitioned between water (200 ml.) and ethyl ether (200 ml.)
12. 12
    抽出extracted with methylene chloride (3×150 ml.)
13. 13
    乾燥dried (magnesium sulfate)
14. 14
    ろ過filtered
15. 15
    その他evaporated
16. 16
    その他to give 20.0 g

実験手順

A solution of lithium diisopropylamide was prepared under nitrogen from diisopropylamine (31.0 ml., 220 mmol.) and n-butyl lithium (1.5M in hexane, 88.0 ml., 220 mmol.) in tetrahydrofuran (80 ml.), maintaining the temperature between -3° C.-1° C. After stirring 15 minutes, cyclopentanecarboxylic acid (11.4 g., 100 mmol.) in tetrahydrofuran (10 ml.) was added at 0° C.-3° C. over 25 minutes. After an additional 15 minutes at 0° C., the bath was removed and the reaction stirred 15 minutes more, causing the temperature to rise to 11° C. The milky white solution was cooled to -74° C. and 1-bromo-4-chlorobutane (23 ml., 200 mmol.) in tetrahydrofuran was added quickly, the temperature rising to -66° C. After 16 hours, the reaction was allowed to warm to room temperature in situ. The reaction was quenched with methanol (10 ml.) and concentrated in vacuo. The residue was partitioned between water (200 ml.) and ethyl ether (200 ml.). The aqueous layer was acidified to pH 1 with 12M hydrochloric acid and extracted with methylene chloride (3×150 ml.), dried (magnesium sulfate), filtered and evaporated to give 20.0 g. of the title product as a yellow oil.

出典