Reaction #1519089

Reaction equation

sodium hydride

tetraethylene glycol

mesylate

tetraethylene glycol monobenzylether

→

compound 25

Yield 34.5%

Octaethylene glycol monobenzylether

Yield 34.5%

Solvents

tetrahydrofuran

tetrahydrofuran

tetrahydrofuran

Conditions

Workup

1. 1
   workup.ADDITIONwas added dropwise
2. 2
   workup.STIRRINGthe reaction mixture was stirred overnight
3. 3
   OtherThe crude reaction mixture
4. 4
   Filtrationwas filtered through Celite (washed, CH2Cl2, 250 mL)
5. 5
   Washthe filtrate was washed H2O, dried MgSO4
6. 6
   Otherevaporated to dryness
7. 7
   OtherThe resultant oil was chromatographed (silica, ethyl acetate/methanol, 10:1)
8. 8
   Otherchromatographed (silica, chloroform/methanol, 25:1)

Procedure

To a solution of tetrahydrofuran (140 mL) containing sodium hydride (0.43 g, 18 mmol) was added dropwise a solution of monodispersed tetraethylene glycol (3.5 g, 18 mmol) in tetrahydrofuran (10 mL) and the reaction mixture was stirred for 1 h. Then mesylate of monodispersed tetraethylene glycol monobenzylether 24 (6.0 g, 16.5 mmol) dissolved in tetrahydrofuran (10 mL) was added dropwise and the reaction mixture was stirred overnight. The crude reaction mixture was filtered through Celite (washed, CH2Cl2, 250 mL) and the filtrate was washed H2O, dried MgSO4, and evaporated to dryness. The resultant oil was chromatographed (silica, ethyl acetate/methanol, 10:1) and chromatographed (silica, chloroform/methanol, 25:1) to afford the monodispersed compound 25 as a clear oil (2.62 g, 34% yield).

Source