反应详情

9 g of 1-(4-chlorophenylmethyl)-2-mercapto-5-fluorobenzimidazole, prepared in Example 15, and 4.4 ml of ethyl 4-bromobutyrate are refluxed for 5 hours in 100 ml of acetone in the presence of 6.3 g of potassium carbonate. The solvent is evaporated off under vacuum, the residue is taken up with water and then extracted with ethyl acetate and the extract is washed with a dilute solution of sodium hydroxide. The organic phase is dried over magnesium sulfate and evaporated under vacuum to give 11.9 g of ethyl 4-[1-(4-chlorobenzyl)-5-fluorobenzimidazol-2-yl]mercaptobutanoate in the form of an oil, which is used as such for the next step.

1. customThe solvent is evaporated off under vacuum
2. extractionextracted with ethyl acetate
3. washthe extract is washed with a dilute solution of sodium hydroxide
4. dry with materialThe organic phase is dried over magnesium sulfate
5. customevaporated under vacuum