反应详情

A solution of 560 mg (2.7 mmol) of 1,3-dicyclohexylcarbodiimide in 5 mL of acetonitrile was added with stirring to a mixture of 2-methyl-4-methylsulfonyl-3-(4-methylsulfonylphenyl)benzoic acid and 378 mg (2.7 mmol) of 1-(1,1-dimethylethyl)-5-hydroxypyrazole in 15 mL of acetonitrile. The mixture was allowed to react for 1 hour and was then filtered. The solids were washed with a little acetonitrile. Triethylamine (1.13 mL, 8.1 mmol) and 274 microliters (2.7 mmol) of acetone cyanohydrin were added with stirring to the combined filtrate and acetonitrile wash. After 3 hours, the mixture was diluted with dichloromethane and the resulting solution was washed with 2N aqueous hydrochloric acid, filtered, and concentrated by evaporation under reduced pressure. The residue was dissolved in the minimum amount of hot ethanol and the solution was then cooled. The precipitate that formed was collected by filtration and dried to obtain the title compound as a pale yellow powder melting at 187-188° C.

1. customto react for 1 hour
2. filtrationwas then filtered
3. washThe solids were washed with a little acetonitrile
4. washwash
5. additionthe mixture was diluted with dichloromethane
6. washthe resulting solution was washed with 2N aqueous hydrochloric acid
7. filtrationfiltered
8. concentrationconcentrated by evaporation under reduced pressure
9. dissolutionThe residue was dissolved in the minimum amount of hot ethanol
10. temperaturethe solution was then cooled
11. customThe precipitate that formed
12. filtrationwas collected by filtration
13. customdried