Réaction #531888

Équation de réaction

dimethyl formamide

POCl3

2-chloro-3-acetyl-pyridine

dimethyl formamide

hydroxylamine hydrochloride

→

3-chloro-3-(2-chloropyridin-3-yl)acrylonitrile

Rendement 81.0%

Conditions de réaction

Traitement

1. 1
   workup.ADDITIONOnce all added the reaction
2. 2
   Températurewas warmed to 50° C.
3. 3
   workup.STIRRINGstirred for 8 h
4. 4
   TempératureThe mixture was cooled to 0° C.
5. 5
   workup.ADDITIONOnce all added the reaction
6. 6
   workup.STIRRINGwas stirred at room temperature for 2 h
7. 7
   Autrequenched with water
8. 8
   Extractionextracted with ethylacetate
9. 9
   LavageThe organic layer was washed with brine
10. 10
    Séchagedried over MgSO4
11. 11
    AutreRemoval of all volatiles under reduced pressure

Mode opératoire

100 ml of dimethyl formamide (DMF) were cooled to 0° C. and POCl3 (35.47 g, 231 mmol, 3 eq.) added dropwise. The reaction was stirred 30 min at 0° C. and a solution of 2-chloro-3-acetyl-pyridine (12 g, 77.12 mmol, 1 eq.) in 15 ml of dimethyl formamide (DMF) was added. Once all added the reaction was warmed to 50° C. and stirred for 8 h. The mixture was cooled to 0° C. and hydroxylamine hydrochloride (21.43 g, 308 mmol, 4 eq.) was added by portions very carefully (exothermic). Once all added the reaction was stirred at room temperature for 2 h and quenched with water. The medium was basified until pH 2-3 was reached with 1N aqueous NaOH and extracted with ethylacetate. The organic layer was washed with brine and dried over MgSO4. Removal of all volatiles under reduced pressure afforded 3-chloro-3-(2-chloropyridin-3-yl)acrylonitrile (13.21 g, 81% yield) as a mixture of isomers which was used without further purification.

Source