Reaktion #5602

Reaktionsgleichung

acryloyl chloride

( 2 )

5-amino-2-methylbenzoxazole

triethylamine

→

5-acrylamido-2-methyl benzoxazole

Lösungsmittel

tetrahydrofuran

tetrahydrofuran

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigeequipped with a mechanical stirrer
2. 2
   workup.ADDITIONadded dropwise to the flask
3. 3
   Sonstigeto return to room temperature
4. 4
   workup.STIRRINGwhile being stirred overnight
5. 5
   Filtrationfiltered
6. 6
   workup.STIRRINGThe filter is stirred in about 1 liter of warm tetrahydrofuran for about thirty minutes
7. 7
   Filtrationfiltered again
8. 8
   workup.ADDITIONabout 10 ml of nitrobenzene are added
9. 9
   Sonstigepolymerization
10. 10
    SonstigeSolvent is removed
11. 11
    Sonstigea rotary evaporator and ethyl ether
12. 12
    workup.ADDITIONis added
13. 13
    SonstigeThe dark brown solid obtained
14. 14
    Filtrationafter filtering
15. 15
    Waschenis washed with methylene chloride

Vorschrift

About 150 parts of (2) are dissolved in about 1200 ml of warm tetrahydrofuran in a 3 liter three-necked flask equipped with a mechanical stirrer and dropping funnel. About 113 parts of triethylamine are added to the flask and then cooled to 0° C. using an ice bath. About 100 parts of acryloyl chloride are combined with about 300 ml of tetrahydrofuran in a dropping funnel and added dropwise to the flask while stirring under dry nitrogen. The mixture in the flask is allowed to return to room temperature while being stirred overnight and then filtered. The filter is stirred in about 1 liter of warm tetrahydrofuran for about thirty minutes and filtered again. Both filtrates are combined and about 10 ml of nitrobenzene are added to inhibit polymerization. Solvent is removed using a rotary evaporator and ethyl ether is added to solidify the product. The dark brown solid obtained after filtering is washed with methylene chloride, then ethyl ether to provide 5-acrylamido-2-methyl benzoxazole (3) as a tan solid after drying under vacuum.

Quelle