Reaktion #79352

Reaktionsgleichung

ethyl 7-(3-hydroxypropoxy)-2-ethylchromane-2-carboxylate

triphenylphosphine

carbon tetrabromide

→

title compound

Ausbeute 96.3%

Ethyl 7-(3-bromopropoxy)-2-ethylchromane-2-carboxylate

Ausbeute 96.3%

Lösungsmittel

CH3CN

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturupon cooling in an ice-water bath
2. 2
   Sonstigethe solvent was removed under reduced pressure
3. 3
   workup.ADDITIONwas charged onto a silica gel column
4. 4
   WaschenElution with 10% AcOEt/hexanes

Vorschrift

To a 100 ml CH3CN solution of ethyl 7-(3-hydroxypropoxy)-2-ethylchromane-2-carboxylate (2.88 g, 9.4 mmol) was added triphenylphosphine (3.21 g, 12.2 mmol) and carbon tetrabromide (4.05 g, 12.2 mmol) upon cooling in an ice-water bath. After stirring at rt for 1 hr, the solvent was removed under reduced pressure. The residue was suspended in dichloromethane and was charged onto a silica gel column. Elution with 10% AcOEt/hexanes gave the title compound 3.36 g (96%).

Quelle