反应详情

A solution of 51.5 mg of lithium hydroxide monohydrate in 8 ml of water was added to a solution of 600 mg of ethyl 2-ethoxymethyl-4-(1-hydroxy-1-methylethyl)-1-{4-[2-(trityltetrazol-5-yl)phenyl]phenyl}methylimidazole-5-carboxylate [prepared as described in Example 86(a)] in 19.5 ml of dioxane, whilst ice-cooling, and the mixture was stirred at 5°-10° C. for 16 hours. At the end of this time, a small piece of dry ice was added, and the reaction solution was concentrated by evaporation under reduced pressure down to approximately 8 ml. The concentrate was then mixed with ethyl acetate and sodium chloride and stirred. The ethyl acetate layer was separated and dried over anhydrous sodium sulfate, and the solvent was removed by distillation under reduced pressure, to give lithium 2-ethoxymethyl-4-(1-hydroxyl-methylethyl)-1-{4-[2-(trityltetrazol-5-yl)phenyl]phenyl}methylimidazole-5-carboxylate as an amorphous powder. The whole of this product was dissolved in 6 ml of N,N-dimethylacetamide, and 113 mg of potassium carbonate were added to the resulting solution, after which a solution of 240 mg of 4-chloromethyl-5-methyl-2-oxo-1,3-dioxolene (purity grade: 74%) in 2 ml of N,N-dimethylacetamide was added dropwise to the mixture. The mixture was then stirred at 50° C. for 1 hour, after which it was mixed with ethyl acetate and water. The ethyl acetate layer was separated and dried over anhydrous magnesium sulfate, and then the solvent was removed by distillation under reduced pressure. The resulting residue was purified by column chromatography through silica gel, using a 3:1 by volume mixture of methylene chloride and ethyl acetate as the eluent, to give 548 mg of the title compound as crystals, melting at 129°-130.5° C.

1. temperaturecooling
2. concentrationthe reaction solution was concentrated by evaporation under reduced pressure down to approximately 8 ml
3. additionThe concentrate was then mixed with ethyl acetate and sodium chloride
4. stirringstirred
5. customThe ethyl acetate layer was separated
6. dry with materialdried over anhydrous sodium sulfate
7. customthe solvent was removed by distillation under reduced pressure