Reaktion #1798523

Reaktionsgleichung

n-BuOH

Compound C5

1-Methyl-4-{3-[(4-nitroanilino)carbonyl]anilino}pyridinium 4-methylbenzenesulfonate

H2O

HCl

→

C6

Ausbeute 80.0%

4-{3-[(4-aminoanilino)carbonyl]anilino}-1-methylpyridinium chloride

Ausbeute 80.0%

Lösungsmittel

EtOH

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturto reflux
2. 2
   Temperaturrefluxing
3. 3
   SonstigeH2O:CH3CO2H showed complete consumption of starting material)
4. 4
   workup.ADDITIONThe reaction mixture was diluted with EtOH (100 mL)
5. 5
   Temperaturto reflux
6. 6
   FiltrationThe hot reaction mixture was filtered through a pad of Celite
7. 7
   Filtrationfiltered (this procedure
8. 8
   Extraktionextraction of product from iron residues)
9. 9
   SonstigeThe combined EtOH extracts were evaporated to dryness
10. 10
    Extraktionthe residue was extracted with hot water
11. 11
    Filtrationfiltered through a pad of Celite
12. 12
    EinengenThe filtrate was concentrated to a smaller volume
13. 13
    Wascheneluted with water
14. 14
    workup.ADDITIONFractions containing product
15. 15
    Sonstigeevaporated to dryness
16. 16
    Sonstigethe residue was azeotroped several times with EtOH
17. 17
    workup.DISSOLUTIONThe residue was dissolved in a small volume of MeOH, methanolic HCl (1.25 M, 1 mL)
18. 18
    workup.ADDITIONwas added
19. 19
    workup.STIRRINGthe solution stirred for 10 min
20. 20
    workup.ADDITIONThe solution was diluted with EtOAc
21. 21
    Filtrationthe resulting precipitate filtered
22. 22
    Sonstigecrystallized from MeOH/EtOAc

Vorschrift

Compound C5 (1.59 g, 3.06 mmol) was dissolved in ˜6:1 EtOH:H2O (46 mL), Fe dust (885 mg) was added, and the resulting suspension brought to reflux. Two drops of c.HCl were added, and refluxing was continued for 1 h. (until TLC with the top phase of 5:4:1 mixture of n-BuOH:H2O:CH3CO2H showed complete consumption of starting material). The reaction mixture was diluted with EtOH (100 mL) and brought to reflux. The hot reaction mixture was filtered through a pad of Celite, and the top layer of the Celite pad was boiled with more EtOH and filtered (this procedure was repeated three times to ensure complete extraction of product from iron residues). The combined EtOH extracts were evaporated to dryness, and the residue was extracted with hot water, and filtered through a pad of Celite. The filtrate was concentrated to a smaller volume, and then stirred in pre-washed ion-exchange resin (55 g). The resulting slurry was loaded onto a column packed with pre-washed ion-exchange resin and eluted with water. Fractions containing product were combined and evaporated to dryness, and the residue was azeotroped several times with EtOH. The residue was dissolved in a small volume of MeOH, methanolic HCl (1.25 M, 1 mL) was added, and the solution stirred for 10 min. The solution was diluted with EtOAc, and the resulting precipitate filtered and then crystallized from MeOH/EtOAc to give C6 (873 mg, 80%); mp (MeOH/EtOAc)>300° C.; 1H NMR [(CD3)2SO] δ 10.77 (br s, 1 H, NH), 9.95 (s, 1H, NH), 8.41 (br d, J=5.5 Hz, 2H, Py H-2, 6), 7.87-7.84 (m, 2H, H-2, 4), 7.61 (t, J=7.8 Hz, 1H, H-5), 7.49 (br d, J=7.8 Hz, 1H, H-6), 7.37 (d, J=8.7 Hz, 2H, H-2+, 6′), 7.21 (br d, J=4.6 Hz, 2H py H-3, 5), 6.55 (d, J=8.8 Hz, 2H, H-3′, 5′), 4.93 (s, 2H, NH2), 3.97 (s, 3H, N+CH3).

Quelle