反应详情

温度

5 °C

0.58 cm3 of butyryl chloride is added to 1 g of 5-nitro-1H-indazole-3-amine, prepared as described in, SU 742430 (CA: 94 :65676) in 25 cm3 of pyridine, and cooled to about 5° C. The reaction medium is allowed to return to about 19° C. over 12 hours. The insoluble material present is filtered off and the filtrate is then evaporated under reduced pressure (2 kPa; 50° C.). The residue is taken up in 15 cm3 of ethyl acetate and 15 cm3 of distilled water. The organic phase is dried over magnesium sulphate, filtered through a sinter funnel and then evaporated under reduced pressure (2 kPa; 50° C.). The residue is purified by chromatography under an argon pressure of 50 kPa, on a column of silica gel (particle size 40-60 μm; diameter 3.5 cm), eluting with a cyclohexane/ethyl acetate mixture (70/30 by volume) and collecting 20 cm3 fractions. The fractions containing the expected product are combined and evaporated under reduced pressure (2 kPa; 50° C.). After drying (90 Pa; 50° C.), 480 mg of N-[5-nitro-1H-indazol-3-yl]butanamide are thus obtained in the form of a white solid.

1. customprepared
2. filtrationThe insoluble material present is filtered off
3. customthe filtrate is then evaporated under reduced pressure (2 kPa; 50° C.)
4. dry with materialThe organic phase is dried over magnesium sulphate
5. filtrationfiltered through a sinter funnel
6. customevaporated under reduced pressure (2 kPa; 50° C.)
7. customThe residue is purified by chromatography under an argon pressure of 50 kPa
8. washon a column of silica gel (particle size 40-60 μm; diameter 3.5 cm), eluting with a cyclohexane/ethyl acetate mixture (70/30 by volume)
9. customcollecting 20 cm3 fractions
10. additionThe fractions containing the expected product
11. customevaporated under reduced pressure (2 kPa; 50° C.)
12. dry with materialAfter drying (90 Pa; 50° C.), 480 mg of N-[5-nitro-1H-indazol-3-yl]butanamide
13. customare thus obtained in the form of a white solid