Reaktion #4561

Reaktionsgleichung

n-butyllithium

2-(4-(4-bromo-2-fluorophenoxy)phenoxy)propanaldehyde

diisopropylamine

ethyl acetate

NH4Cl

→

product

Ausbeute 70.0%

4-(4-(4-Bromo-2-fluorophenoxy)phenoxy)-3-hydroxypentanoate ethyl ester

Ausbeute 70.0%

Lösungsmittel

hexane

ether

ether

ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas slowly added
2. 2
   Sonstigethe aqueous phase separated
3. 3
   Extraktionextracted with ether
4. 4
   TrocknenThe combined organic layers were dried over MgSO4
5. 5
   Sonstigeevaporated to dryness
6. 6
   Sonstigethe residue purified by prep LC
7. 7
   Wascheneluting with 85:15 hexane
8. 8
   SonstigeThe resulting colorless oil was thoroughly dried

Vorschrift

A solution of 1.54 ml (11 mmol) of diisopropylamine in 20 ml of ether was cooled under N2 to -78° C. and 6.9 ml (11 mmol) of 1.6M n-butyllithium in hexane was slowly added. After 15 min of -78° C. 0.97 g (11 mmol) of ethyl acetate in 3 ml of ether was added dropwise. The resulting mixture was stirred at -78° C. for 15 min when a solution of 3.39 g (10 mmol) of 2-(4-(4-bromo-2-fluorophenoxy)phenoxy)propanaldehyde in 5 ml of ether was slowly added. The mixture was allowed to warm to room temperature, poured into aqueous NH4Cl and the aqueous phase separated and extracted with ether. The combined organic layers were dried over MgSO4 and evaporated to dryness and the residue purified by prep LC, eluting with 85:15 hexane:acetone. The resulting colorless oil was thoroughly dried to leave 2.99 g of product. Structure was confirmed by IR and NMR analysis. Calc. for C17H20BrFO5 : C, 53.41, H, 4.72. Found: C, 53.10, H, 4.66.

Quelle