反应详情

To a suspension of 4,5-diamino-1-methylpyrazole sulfuric acid salt (305 g) in tetrahydrofuran (3.05 L) was added tert-butyl 2-[(2,5-dioxo-1-pyrrolidinyl)oxyl]-2-oxoethylcarbamate (415 g) under ice-cooling. To the mixture was added diisopropylethylamine (556 ml) dropwise at a temperature below 10° C. The mixture was stirred at room temperature overnight. To the resulting solution were added brine and saturated aqueous sodium hydrogen carbonate solution, and the mixture was extracted with ethyl acetate (3.0 L). The aqueous layer was extracted with tetrahydrofuran/ethyl acetate=1/1 (3.0 L) twice. The organic layer was dried over anhydrous magnesium sulfate, filtered and concentrated in vacuo. The residue was triturated with diisopropyl ether (1.0 L) and dried in vacuo to give tert-butyl 2-[(5-amino-1-methyl-1H-pyrazol-4-yl)amino]-2-oxoethylcarbamate (307 g).

1. temperaturecooling
2. extractionthe mixture was extracted with ethyl acetate (3.0 L)
3. extractionThe aqueous layer was extracted with tetrahydrofuran/ethyl acetate=1/1 (3.0 L) twice
4. dry with materialThe organic layer was dried over anhydrous magnesium sulfate
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customThe residue was triturated with diisopropyl ether (1.0 L)
8. customdried in vacuo