تفاعل #1786192

معادلة التفاعل

Et2O

ethyl glycolate

sodium bis(trimethylsilyl)amide

1,4-dibromobutane

1,4-dibromobutane

→

(4-bromo-butoxy)-acetic acid ethyl ester

المردود 17.7%

المذيبات

EtOAc

—

hexanes

DMF

ظروف التفاعل

المعالجة

1. 1
   workup.STIRRINGwas stirred for 24 h
2. 2
   غسيلthe organic solution was washed consecutively with HCl (1N, 3×), water (3×), and brine (1×)
3. 3
   تجفيفThe organic solution was dried (Na2SO4)
4. 4
   ترشيحfiltered
5. 5
   تركيزconcentrated
6. 6
   workup.DISTILLATIONvacuum distillation
7. 7
   أخرىremoved a majority of the impurities
8. 8
   أخرىprovided

الإجراء التجريبي

A solution of ethyl glycolate (4.6 g, 44 mmol) in DMF (50 mL) was cooled to 0° C. and sodium bis(trimethylsilyl)amide (1.0 M in THF, 53 mL, 53 mmol) was slowly added. The reaction was stirred for 15 minutes and 1,4-dibromobutane (5.6 mL, 48.4 mmol) was added. The reaction was warmed to room temperature and was stirred for 24 h. Et2O was added, and the organic solution was washed consecutively with HCl (1N, 3×), water (3×), and brine (1×). The organic solution was dried (Na2SO4), filtered, and concentrated. Attempted vacuum distillation removed a majority of the impurities and provided a mixture of product and 1,4-dibromobutane (3.539 g). Flash chromatography (9:1 hexanes:EtOAc) of this material provided (4-bromo-butoxy)-acetic acid ethyl ester (1.862 g). 1H NMR (400 MHz, CDCl3) δ4.19 (q, 2H), 4.04 (s, 2H), 3.54 (t, 2H), 3.45 (t, 2H), 1.97 (m, 2H), 1.75 (m, 2H), 1.26 (t, 3H); MS 239.1 (M+).

المصدر