Reaktion #1435678

Reaktionsgleichung

sodium sulfide nonahydrate

methyl 2,3-diaminobenzoate

N-acetylpiperidine-4-carbaldehyde

hydrochloricacid

→

product

Ausbeute 75.0%

Methyl 2-(N-acetylpiperidin-4-yl)benzimidazole-4-carboxylate

Ausbeute 75.0%

Lösungsmittel

water

water

water

methanol

methanol

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwere added dropwise
2. 2
   Temperaturthe whole was refluxed for 30 minutes
3. 3
   TemperaturAfter cooling
4. 4
   Temperaturthe whole was again refluxed
5. 5
   workup.ADDITIONwere then added dropwise
6. 6
   workup.WAITthe whole was boiled for a further 10 minutes
7. 7
   TemperaturAfter cooling
8. 8
   Sonstigethe reaction solution was evaporated down under reduced pressure
9. 9
   SonstigeThe residue obtained
10. 10
    Filtrationfiltered
11. 11
    Extraktionwas extracted several times with ethyl acetate
12. 12
    WaschenThe combined organic phases were washed with water
13. 13
    Sonstigedried
14. 14
    Sonstigeevaporated down under reduced pressure

Vorschrift

3.3 g (19.9 mmol) of methyl 2,3-diaminobenzoate were dissolved in 100 ml of methanol, and a solution of 4.0 g (25.8 mmol) of N-acetylpiperidine-4-carbaldehyde in 100 ml of methanol was added dropwise at room temperature. The whole was stirred for about 10 minutes at room temperature. Thereafter, 5.2 g (25.8 mmol) of copper(II) acetate, which was dissolved in 100 ml of water, were added dropwise and the whole was refluxed for 30 minutes. After cooling, 25 ml of concentrated hydrochloricacid were added carefully and the whole was again refluxed. 7.15 g (29.8 mmol) of sodium sulfide nonahydrate, dissolved in 100 ml of water, were then added dropwise and the whole was boiled for a further 10 minutes. After cooling, the reaction solution was evaporated down under reduced pressure. The residue obtained was dispersed in water and filtered. The filtrate was rendered alkaline with aqueous sodium bicarbonate solution and was extracted several times with ethyl acetate. The combined organic phases were washed with water, dried and evaporated down under reduced pressure. 4.5 g of the product were obtained.

Quelle