Reaktion #715754

Reaktionsgleichung

biphenyl-3,3′,4,4′-tetraamine

4-aminobenzoic acid

water

→

product

Ausbeute 97.5%

4,4′-(1H,3′H-5,5′-Bibenzo[d]imidazole-2,2′-diyl)dianiline

Ausbeute 97.5%

Lösungsmittel

MeOH

Reaktionsbedingungen

Aufarbeitung

1. 1
   workup.ADDITIONwas added portionwise
2. 2
   workup.STIRRINGThe mixture was stirred at 200° C. for 2.5 h
3. 3
   TemperaturThe mixture was cooled (to <100° C.)
4. 4
   workup.STIRRINGThe resulting mixture was stirred until a uniform green precipitate
5. 5
   Sonstigehad formed
6. 6
   FiltrationThe solid was filtered off
7. 7
   Waschenwashed with aqueous K2CO3 and water
8. 8
   Sonstigedried under suction
9. 9
   SonstigeThe crude product was purified by column chromatography (99:1 EtOAc-NEt3 to 89:10:1 EtOAc-MeOH-NEt3)
10. 10
    Sonstigeto afford a yellow solid
11. 11
    Einengen1M HCl, and then concentrated in vacuo
12. 12
    workup.STIRRINGstirred in aqueous NaHCO3
13. 13
    FiltrationThe solid was filtered
14. 14
    Waschenwashed with water
15. 15
    Sonstigedried (vacuum oven)

Vorschrift

A homogenous mixture of biphenyl-3,3′,4,4′-tetraamine (500 mg, 2.34 mmol) and 4-aminobenzoic acid (640 mg, 4.67 mmol) was added portionwise to stirred PPA (20 mL) at 200° C. The mixture was stirred at 200° C. for 2.5 h. The mixture was cooled (to <100° C.) and poured into water. The resulting mixture was stirred until a uniform green precipitate had formed. The solid was filtered off and washed with aqueous K2CO3 and water, then dried under suction. The crude product was purified by column chromatography (99:1 EtOAc-NEt3 to 89:10:1 EtOAc-MeOH-NEt3) to afford a yellow solid. This was dissolved in MeOH and 1M HCl, and then concentrated in vacuo. The material was then ground to a fine powder and stirred in aqueous NaHCO3. The solid was filtered, washed with water and dried (vacuum oven) to give the product as a yellow solid (475 mg, 49%).

Quelle