反应详情

1.76 ml of N,N-diisopropylethylamine were added to a suspension of 1.14 g of 4-(1-hydroxy-1-methylethyl)-2-propylimidazole-5-carboxylic acid [prepared as described in step (i) above] in 12 ml of N,N-dimethylacetamide, and the resulting mixture was stirred at room temperature for 10 minutes; 1.36 ml of pivaloyloxymethyl chloride was then added. The reaction mixture was stirred at 60° C. for 4 hours, after which it was mixed with ethyl acetate and water. The ethyl acetate layer was separated and concentrated by evaporation under reduced pressure. The crystals which precipitated were triturated with diisopropyl ether and collected by filtration to give 1.53 g of the title compound, melting at 177° C.

1. stirringThe reaction mixture was stirred at 60° C. for 4 hours
2. customThe ethyl acetate layer was separated
3. concentrationconcentrated by evaporation under reduced pressure
4. customThe crystals which precipitated
5. customwere triturated with diisopropyl ether
6. filtrationcollected by filtration