Reaktion #78876

Reaktionsgleichung

pent-4-enoic acid

isobutyl chloroformate

triethylamine

triethylamine

2-(3-diisopropylamino-1-phenylpropyl)-4-hydroxymethylphenol

→

(±)-pent-4-enoic acid 2-(3-diisopropyl amino-1-phenylpropyl)-4-(pent-4-enoyloxymethyl)-phenyl ester

Ausbeute 50.0%

Lösungsmittel

dichloromethane

dichloromethane

Reaktionsbedingungen

Aufarbeitung

1. 1
   TemperaturA cooled
2. 2
   SonstigeThe cooling bath was then removed
3. 3
   Waschenwashed several times with water and finally aqueous 5% sodium hydrogen carbonate solution
4. 4
   SonstigeAfter drying
5. 5
   Filtration(sodium sulphate), filtration and evaporation the oily residue
6. 6
   workup.DISSOLUTIONwas re-dissolved in a small volume of a solvent mixture
7. 7
   WaschenElution of the column
8. 8
   Sonstigewith the same solvent mixture, collection of the appropriate fractions, and evaporation of the combined fractions

Vorschrift

A cooled (4° C.) mixture of pent-4-enoic acid, isobutyl chloroformate, and triethylamine (each 5.84 mmol) in 10 ml of dichloromethane was stirred 5 hrs under an atmosphere of dry nitrogen gas. The cooling bath was then removed and both triethylamine (1.46 mmol) and 2-(3-diisopropylamino-1-phenylpropyl)-4-hydroxymethylphenol (1.46 mmol) were added in one portion. After 18 hrs the mixture was diluted with dichloromethane 30 ml), washed several times with water and finally aqueous 5% sodium hydrogen carbonate solution. After drying (sodium sulphate), filtration and evaporation the oily residue was re-dissolved in a small volume of a solvent mixture consisting of ethyl acetate/heptane/triethylamine (65/30/5, vol.-%) and applied on a silica gel flash chromatography column. Elution of the column with the same solvent mixture, collection of the appropriate fractions, and evaporation of the combined fractions gave (±)-pent-4-enoic acid 2-(3-diisopropyl amino-1-phenylpropyl)-4-(pent-4-enoyloxymethyl)-phenyl ester as a pale yellow syrupy oil (50% yield), tlc: (4) 0.75. NMR (CDCl3): 18.95, 20.77, 27.75, 28.87, 33.58, 36.83, 42.13, 43.72, 48.71, 65.85, 70.55, 115.47, 115.99, 122.45, 126.26, 127.08, 127.96, 128.11, 128.83, 133.73, 136.38, 136.79, 137.04, 143.77, 148.46, 171.11, 172.78.

Quelle