Reaktion #90659

Reaktionsgleichung

HCl

acetone

ethyl phenylacetate

→

1-phenyl-2,4-pentanedione

Ausbeute 69.3%

Lösungsmittel

ether

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONAfter addition
2. 2
   SonstigeThe organic layer was separated
3. 3
   Einengenconcentrated in vacuo
4. 4
   SonstigeThe crude product was purified by silica gel chromatography

Vorschrift

To a solution of NaNH2 (19.02 g, 480 mmol) in anhydrous ether (400 mL) under N2 at −5° C. was added dropwise ethyl phenylacetate (19.2 g, 150 mmol) and then acetone (21.23 g, 370 mmol) with vigorous stirring. After addition, the reaction mixture was stirred at room temperature overnight. The mixture was then acidified to pH 4.0-5.0 with 1N HCl. The organic layer was separated and concentrated in vacuo. The crude product was purified by silica gel chromatography to give 1-phenyl-2,4-pentanedione (18.32 g, 44%). 1H NMR (400 MHz, CDCl3-d3) δ 15.49 (br s, 1H), 7.33-7.45 (m, 5H), 5.53 (s, 1H), 3.66 (s, 2H), 2.10 (s, 3H).

Quelle