Reaktion #1810329

Reaktionsgleichung

ammonium hydroxide

4-(1H-imidazol-1-ylmethyl)-1,2-benzenediamine

3-thiophenecarboxaldehyde

hydrochloric acid

→

5-(1H-imidazol-1-ylmethyl)-2-(3-thienyl)-1H-benzimidazole dihydrochloride

Ausbeute 8.5%

Reaktionsbedingungen

Aufarbeitung

1. 1
   Temperaturat reflux temperature
2. 2
   TemperaturAfter cooling
3. 3
   ExtraktionThe product was extracted three times with 75 parts of trichloromethane
4. 4
   SonstigeThe combined extracts were dried
5. 5
   Filtrationfiltered
6. 6
   Sonstigeevaporated
7. 7
   SonstigeThe residue was purified by column chromatography (HPLC) over silica gel using
8. 8
   workup.ADDITIONa mixture of trichloromethane, methanol and ammonium hydroxide (90:10:0.1 by volume) as eluent
9. 9
   SonstigeThe pure fractions were collected
10. 10
    Sonstigethe eluent was evaporated
11. 11
    Sonstigewas converted into the hydrochloride salt in 8 parts of 2-propanone and ethanol at 0° C
12. 12
    FiltrationThe salt was filtered off
13. 13
    Sonstigecrystallized from a mixture of methanol and 2-propanone
14. 14
    FiltrationThe product was filtered off
15. 15
    Sonstigedried

Vorschrift

A mixture of 5 parts of 4-(1H-imidazol-1-ylmethyl)-1,2-benzenediamine, 3 parts of 3-thiophenecarboxaldehyde and 50 parts of a hydrochloric acid solution 3N was stirred for 36 hours at reflux temperature. After cooling, the mixture was poured into 100 parts of crushed ice and ammonium hydroxide. The product was extracted three times with 75 parts of trichloromethane. The combined extracts were dried, filtered and evaporated. The residue was purified by column chromatography (HPLC) over silica gel using a mixture of trichloromethane, methanol and ammonium hydroxide (90:10:0.1 by volume) as eluent. The pure fractions were collected and the eluent was evaporated. The residue was converted into the hydrochloride salt in 8 parts of 2-propanone and ethanol at 0° C. The salt was filtered off and crystallized from a mixture of methanol and 2-propanone. The product was filtered off and dried, yielding 0.8 parts (8.5%) of 5-(1H-imidazol-1-ylmethyl)-2-(3-thienyl)-1H-benzimidazole dihydrochloride; mp.>300° C. (dec.) (compound 205).

Quelle