1,1'-Carbonyldiimidazole → 1H-Benzimidazole, 1-methyl-

A mixture of 5.6 parts of 1-methyl-α-phenyl-1H-benzimidazole-5-methanol, 4.05 parts of 1,1'-carbonylbis[1H-imidazole] and 54 parts tetrahydrofuran was stirred for 4 hours at reflux temperature. The tetrahydrofuran layer was evaporated and water was added to the residue. The decanted oil was dissolved in dichloromethane. The organic layer was dried, filtered and evaporated. The residue was purified by column chromatography over silica gel using a mixture of trichloromethane, methanol and methanol, saturated with ammonia, (90:5:5 by volume) as eluent. The pure fractions were collected and the eluent was evaporated. The residue was further purified by column chromatography over silica gel using a mixture of trichloromethane and methanol (93:7 by volume) as eluent. The pure fractions were collected and the eluent was evaporated. The residue was washed with 2,2'-oxybispropane and dried, yielding 2.9 parts (42.9%) of 5-[1H-imidazol-1-yl)phenylmethyl]-1-methyl-1H-benzimidazole; mp. 138.7° C. (comp. 21).

1. temperatureat reflux temperature
2. customThe tetrahydrofuran layer was evaporated
3. additionwater was added to the residue
4. dissolutionThe decanted oil was dissolved in dichloromethane
5. customThe organic layer was dried
6. filtrationfiltered
7. customevaporated
8. customThe residue was purified by column chromatography over silica gel using
9. additiona mixture of trichloromethane, methanol and methanol
10. customThe pure fractions were collected
11. customthe eluent was evaporated
12. customThe residue was further purified by column chromatography over silica gel using
13. additiona mixture of trichloromethane and methanol (93:7 by volume) as eluent
14. customThe pure fractions were collected
15. customthe eluent was evaporated
16. washThe residue was washed with 2,2'-oxybispropane
17. customdried

ORD record

ord-0c67e6d701f74eaba611e9961cc54131

Source dataset

uspto-grants-1996_03

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US05500435