Reaktion #643084

Reaktionsgleichung

4-aminobutyraldehyde diethyl acetal

triethylamine

2-bromoisobutyryl bromide

→

N-butyraldehyde 2-bromoisobutylamide

Lösungsmittel

—

ice water

THF

Reaktionsbedingungen

Aufarbeitung

1. 1
   FiltrationThe white amine halide salt precipitate was filtered off by Buchner funnel
2. 2
   SonstigeAfter evaporating half of the THF under reduced pressure
3. 3
   workup.ADDITIONthe filtered THF solution was treated with 25 ml of 20% trifluoroacetic acid aqueous solution overnight
4. 4
   workup.ADDITIONThe mixture was neutralised by addition of 5% of NaHCO3 water solution to pH 8
5. 5
   Extraktionthe product aldehyde was extracted three times by 50 ml DCM each time
6. 6
   SonstigeAfter evaporation of DCM
7. 7
   Sonstigea red-yellow liquid was obtained
8. 8
   SonstigeFurther purification
9. 9
   Sonstigestored at −20° C.

Vorschrift

To 100 ml of dry THF, 8.1 g (0.05 mol) 4-aminobutyraldehyde diethyl acetal and 8.4 ml (0.06 mol) triethylamine were added. The reaction flask was kept in ice-water bath, and 2-bromoisobutyryl bromide (7.5 ml, 0.06 mol) was added dropwise by a syringe over 30 min. The reaction was then stirred for 2 hours at room temperature. The white amine halide salt precipitate was filtered off by Buchner funnel. After evaporating half of the THF under reduced pressure, the filtered THF solution was treated with 25 ml of 20% trifluoroacetic acid aqueous solution overnight to cleave the diethyl acetal protection group. The mixture was neutralised by addition of 5% of NaHCO3 water solution to pH 8, and the product aldehyde was extracted three times by 50 ml DCM each time. After evaporation of DCM, a red-yellow liquid was obtained. Further purification was carried out by silicon column using DCM as eluent. The final product is colorless liquid, and stored at −20° C. freezer.

Quelle