반응 #323848

반응 방정식

N,N-dimethylformamide

Vilsmeier reagent

2,6-dimethylpiperidine

α-Hydroxy-2-nitrobenzenepropanoic acid

thionyl chloride

→

α-Chloro-2-nitrobenzenepropanoic acid 2,6-dimethylpiperidine salt

용매

dichloromethane

ether

dichloromethane

반응 조건

후처리

1. 1
   workup.ADDITIONwas added
2. 2
   기타The resulting solution was evaporated to a syrup
3. 3
   workup.DISSOLUTIONThe syrup was dissolved in dichloromethane
4. 4
   workup.ADDITIONthe solution was added
5. 5
   workup.STIRRINGto stirred ice
6. 6
   workup.STIRRINGThe mixture was stirred for 1 hour during which time it
7. 7
   온도warmed to room temperature
8. 8
   기타The dichloromethane solution was separated
9. 9
   세척washed (×4) with water
10. 10
    건조dried (MgSO4)
11. 11
    기타Evaporation
12. 12
    기타gave a syrup which
13. 13
    workup.WAITwas subjected to an oil pump vacuum for half an hour
14. 14
    기타The crude titled product [2.36 g (81%), mp 138°-140° C.] crystallized readily
15. 15
    기타Recrystallization (methanol-ether) with decolorization (Nuchar C-190N)
16. 16
    기타gave pure product, mp 141°-143° C.

실험 절차

To magnetically stirred N,N-dimethylformamide (2 ml, 25.8 mmol) cooled in ice was added slowly dropwise thionyl chloride (3 ml, 41.1 mmol), and the resulting cold Vilsmeier reagent was diluted with dichloromethane (10 ml). α-Hydroxy-2-nitrobenzenepropanoic acid (2.00 g, 9.47 mmol), followed by an additional 2 ml of dichloromethane was added. The mixture, protected from moisture, was stirred at room temperature (25° C.) overnight. The resulting solution was evaporated to a syrup. The syrup was dissolved in dichloromethane and the solution was added to stirred ice. The mixture was stirred for 1 hour during which time it warmed to room temperature. The dichloromethane solution was separated and washed (×4) with water and dried (MgSO4). Evaporation gave a syrup which was subjected to an oil pump vacuum for half an hour. The syrup was dissolved in ether and 2,6-dimethylpiperidine was added to approximate neutrality (pH 9 with pH paper). The crude titled product [2.36 g (81%), mp 138°-140° C.] crystallized readily. Recrystallization (methanol-ether) with decolorization (Nuchar C-190N) gave pure product, mp 141°-143° C.

출처