反应详情

A mixture of ethyl 3,4-diaminobenzoate (0.9 g), 4-(3-piperidinomethylphenoxy)butyric acid (2.1 g) prepared as described in Example 42 and 4N hydrochloric acid (6 ml) was heated and stirred under reflux for 90 minutes. A further portion of the butyric acid (2.1 g) and of 4N hydrochloric acid (6 ml) was added and the mixture heated under reflux for 90 minutes. The reaction mixture was cooled and poured into water (10 volumes). Aqueous ammonia (S.G. 0.880) was added until the solution was alkaline and the mixture was extracted with ethyl acetate. The extracts were washed with water, dried and on removal of the solvent gave a residue which was purified by preparative layer chromatography on silica gel plates using a 1:1 mixture of dichloromethane and methanol to give 5-ethoxycarbonyl-2-[3-(3-piperidinomethylphenoxy)propyl]benzimidazole as an oil.

1. customprepared
2. temperaturewas heated
3. temperatureunder reflux for 90 minutes
4. temperaturethe mixture heated
5. temperatureunder reflux for 90 minutes
6. temperatureThe reaction mixture was cooled
7. extractionthe mixture was extracted with ethyl acetate
8. washThe extracts were washed with water
9. customdried and on removal of the solvent
10. customgave a residue which
11. customwas purified by preparative layer chromatography on silica gel plates
12. additiona 1:1 mixture of dichloromethane and methanol