Reaktion #531854

Reaktionsgleichung

HCl

4-aminobutyric acid

DBU

cyclohexyl isocyanate

→

4-(3-Cyclohexyl-ureido)-butyric acid

Ausbeute 76.0%

Lösungsmittel

NaOH

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONThe mixture was strongly mixed at room temperature overnight
2. 2
   FiltrationThe formed white solid was collected by filtration
3. 3
   SonstigeThe mixture was purified by chromatography on a silica column (8×3 cm)
4. 4
   WaschenElution with a mixture 50:50:1 of hexane
5. 5
   Sonstigeethyl acetate:acetic acid gave the pure targeted product

Vorschrift

To a cold solution of 4-aminobutyric acid (2.16 g, 21 mmol) and catalytic amount of DBU in 22 mL of 1.0 N NaOH, 2.5 g (20 mmol) of cyclohexyl isocyanate were added in one time. The mixture was strongly mixed at room temperature overnight. The reaction was then acidified with concentrated HCl. The formed white solid was collected by filtration. The mixture was purified by chromatography on a silica column (8×3 cm). Elution with a mixture 50:50:1 of hexane:ethyl acetate:acetic acid gave the pure targeted product. The resulting white crystal (3.46 g; yield: 76%) had a mp of 153.0-154.0° C. [M+H]+ 281.18.

Quelle