Reaktion #7630

Reaktionsgleichung

5-methyl-2-aminopyridin

acetyl chloride

furan-2-carbaldehyde

cyclohexylisonitrile

perchloric acid

→

1-acetyl-3-cyclohexylamino-2-furan-2-yl-imidazo[1,2-a]pyridin-1-ium chloride hydrochloride

Lösungsmittel

DCM

water

methanol

DCM

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.STIRRINGstirred for 10 minutes
2. 2
   Sonstigethe phases then separated
3. 3
   ExtraktionThe aqueous phase was additionally extracted three times with 20 ml DCM in each case
4. 4
   workup.STIRRINGthe combined organic phases then shaken briefly with 50 ml saturated sodium chloride solution
5. 5
   Sonstigeseparated off
6. 6
   Trocknendried over magnesium sulphate
7. 7
   Filtrationfiltered
8. 8
   Einengenconcentrated under vacuum
9. 9
   SonstigeThe intermediate product obtained (1.83 g; 6.2 mmol)
10. 10
    workup.STIRRINGwhile stirring at 20° C.
11. 11
    workup.STIRRINGwere stirred for a further four hours
12. 12
    EinengenThe reaction mixture was then concentrated under vacuum
13. 13
    Sonstigedried in an oil pump vacuum
14. 14
    workup.DISSOLUTIONThe untreated product (about 2 g) was dissolved in 15.5 ml 2-butanone
15. 15
    workup.ADDITION51 μl water and 0.72 ml trimethylchlorosilane were added
16. 16
    workup.STIRRINGthe mixture was stirred overnight
17. 17
    FiltrationThe precipitated HCl adduct of 1-acetyl-3-cyclohexylamino-2-furan-2-yl-imidazo[1,2-a]pyridin-1-ium chloride was suction-filtered
18. 18
    Sonstigedried under vacuum

Vorschrift

655 mg (6.1 mmol) 5-methyl-2-aminopyridin were placed in 12 ml methanol, and 874 mg (0.75 ml; 9.1 mmol) furan-2-carbaldehyde, 768 mg (0.86 ml; 7.0 mmol) cyclohexylisonitrile and 0.59 ml aqueous perchloric acid (20 m %) were then added and stirred at ambient temperature for 22 hours. 50 ml water and 40 ml DCM were added for processing purposes, stirred for 10 minutes, and the phases then separated. The aqueous phase was additionally extracted three times with 20 ml DCM in each case and the combined organic phases then shaken briefly with 50 ml saturated sodium chloride solution, separated off, dried over magnesium sulphate, filtered and concentrated under vacuum. The intermediate product obtained (1.83 g; 6.2 mmol) was dissolved in 10 ml DCM, and four equivalents acetyl chloride (24.8 mmol; 1.8 ml) were added dropwise while stirring at 20° C. and were stirred for a further four hours. The reaction mixture was then concentrated under vacuum and dried in an oil pump vacuum. The untreated product (about 2 g) was dissolved in 15.5 ml 2-butanone, 51 μl water and 0.72 ml trimethylchlorosilane were added and the mixture was stirred overnight. The precipitated HCl adduct of 1-acetyl-3-cyclohexylamino-2-furan-2-yl-imidazo[1,2-a]pyridin-1-ium chloride was suction-filtered and dried under vacuum. 776 mg 1-acetyl-3-cyclohexylamino-2-furan-2-yl-imidazo[1,2-a]pyridin-1-ium chloride hydrochloride were obtained.

Quelle