Reaction #1519087

Reaction equation

Mesylate

6-{2-[2-(2-{2-[2-(2-methylsulfonylethoxy)ethoxy]ethoxy}-ethoxy)-ethoxy]-ethoxy}-hexanoic acid ethyl ester

NaH

diethylene glycol monomethyl ether

→

compound 6

Yield 62.6%

6-(2-{2-[2-(2-{2-[2-(2-methoxyethoxy)ethoxy]-ethoxy}-ethoxy)-ethoxy]-ethoxy}-ethoxy)-hexanoic acid ethyl ester

Yield 62.6%

Solvents

toluene

toluene

toluene

Conditions

Workup

1. 1
   workup.ADDITIONwas added
2. 2
   Temperatureto warm to room temperature
3. 3
   workup.STIRRINGAfter stirring at room temperature over night
4. 4
   Otherthe reaction was quenched by the addition of 2 ml of methanol
5. 5
   Filtrationthe resultant solution was filtered through silica gel
6. 6
   ConcentrationThe filtrate was concentrated in vacuo
7. 7
   OtherAdditional purification by preparatory chromatography (silica gel, 19/3 chloroform/methanol)

Procedure

NaH (88 mg of a 60% dispersion in oil, 2.2 mmol) was suspended in anhydrous toluene (3 ml) under N2 and chilled to 0° C. Monodispersed diethylene glycol monomethyl ether (0.26 ml, 0.26 g, 2.2 mmol) that had been dried via azeotropic distillation with toluene was added. The reaction mixture was allowed to warm to room temperature and stirred for four hours, during which time the cloudy grey suspension became clear and yellow and then turned brown. Mesylate 5 (0.50 g, 1.0 mmol) in 2.5 ml dry toluene was added. After stirring at room temperature over night, the reaction was quenched by the addition of 2 ml of methanol and the resultant solution was filtered through silica gel. The filtrate was concentrated in vacuo and the FAB MS: m/e 499 (M+H), 521 (M+Na). Additional purification by preparatory chromatography (silica gel, 19/3 chloroform/methanol) provided the monodispersed compound 6 as a clear yellow oil (0.302 g 57%). FAB MS: m/e 527 (M+H), 549 (M+Na).

Source