Reaktion #82855

Reaktionsgleichung

sodium hydroxide

piperonal

nitromethane

→

3,4-Methylenedioxy-1-(2-nitroethenyl)-benzene

Lösungsmittel

water

water

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   Sonstigewas set to -5° C.
2. 2
   Temperaturthe reaction solution cooled to a temperature of +3.5° C
3. 3
   TemperaturThe reaction temperature was maintained between 10°-15° C
4. 4
   workup.ADDITIONWhen addition
5. 5
   Sonstigewas reset to 1° C.
6. 6
   workup.ADDITIONwas added
7. 7
   workup.DISSOLUTIONto dissolve most of the solid
8. 8
   FiltrationThe reaction mixture was filtered through canvas
9. 9
   Filtrationa 27R10SV Honeycomb filter
10. 10
    Sonstigewas metered into a 21° C.
11. 11
    workup.ADDITIONmixture of 7.4 L concentrated hydrochloric acid in 11.1 L
12. 12
    SonstigeThe final reaction temperature
13. 13
    Sonstigewas 26° C
14. 14
    Waschenwashed until the
15. 15
    Waschenwash
16. 16
    workup.DISSOLUTIONThe crude product was dissolved in 92 L dichloromethane
17. 17
    Sonstigethe layers separated
18. 18
    WaschenThe aqueous layer was washed once with 8 L dichloromethane
19. 19
    TrocknenThe combined organics were dried over 1.32 kg magnesium sulfate
20. 20
    Filtrationfiltered through Whatman #1 paper
21. 21
    FiltrationFiltration through Whatman #1 paper
22. 22
    Sonstigefollowed by ambient temperature
23. 23
    Sonstigedrying in vacuo with an air leak
24. 24
    Sonstigeafforded 1.584 kg (22%) of a first crop Concentration of the MLS to 25%
25. 25
    Filtrationfollowed by similar cooling, filtration
26. 26
    Sonstigedrying
27. 27
    Sonstigeafforded 0.262 kg (4%) of a second crop

Vorschrift

In a 45-L cryogenic reactor with a contoured, anchor stirrer was dissolved 5.537 kg (36.9 moles) piperonal in 9 L methanol and 2.252 kg (36.9 moles) nitromethane at 15°-20° C. The jacket temperature was set to -5° C. and the reaction solution cooled to a temperature of +3.5° C. A 21° C. solution of 3.10 kg (38.8 moles) 50% (w:w) aquous sodium hydroxide diluted with 3.7 L water was pumped in. The reaction temperature was maintained between 10°-15° C. When addition was complete, the jacket temperature was reset to 1° C. and stirring continued for 30 minutes. A mixture of 7 kg ice in 19 L water was added to dissolve most of the solid. The reaction mixture was filtered through canvas and then a 27R10SV Honeycomb filter. The filtered solution was metered into a 21° C. mixture of 7.4 L concentrated hydrochloric acid in 11.1 L deionized water. The final reaction temperature was 26° C. The resulting product was centrifuged and washed until the wash pH rose to at least 6 (by pH indicating paper). The crude product was dissolved in 92 L dichloromethane and the layers separated. The aqueous layer was washed once with 8 L dichloromethane. The combined organics were dried over 1.32 kg magnesium sulfate and filtered through Whatman #1 paper. The volume was reduced to 20% and the solution cooled to 4° C. Filtration through Whatman #1 paper, followed by ambient temperature drying in vacuo with an air leak afforded 1.584 kg (22%) of a first crop Concentration of the MLS to 25% followed by similar cooling, filtration, and drying afforded 0.262 kg (4%) of a second crop. The yellow product darkened on standing in light and air.

Quelle