反应详情

856 mg of zinc powder are added to 0.85 g of N-[6-(4-nitrophenyl)-1H-indazol-3-yl]butanamide, described in Example 64, in 50 cm3 of acetic acid, followed, one hour later, by addition of a further 856 mg of zinc, and the mixture is stirred for 1 hour at room temperature. The reaction medium is filtered through a sinter funnel packed with Celite and the filtrate is concentrated to dryness under reduced pressure (2 kPa; 50° C.). The residue is taken up in 100 cm3 of tetrahydrofuran and 100 cm3 of ethyl acetate and the organic phase is washed successively with 100 cm3 of saturated sodium hydrogen carbonate solution and with 100 cm3 of saturated sodium chloride solution, then dried over magnesium sulphate, filtered and concentrated to dryness to give 500 mg of crude product, which is purified by chromatography under an argon pressure of 50 kPa, on a column of silica gel (particle size 40-60 μm; diameter 4.5 cm), eluting with ethyl acetate. The fractions containing the expected product are combined and the solid is triturated in 20 cm3 of diethyl ether, filtered off, washed with 2×5 cm3 of diethyl ether and then dried (90 Pa; 45° C.) to give 200 mg of N-[6-(4-aminophenyl)-1H-indazol-3-yl]butanamide in the form of yellow crystals melting at 230° C.

1. filtrationThe reaction medium is filtered through a sinter funnel
2. concentrationthe filtrate is concentrated to dryness under reduced pressure (2 kPa; 50° C.)
3. wash100 cm3 of ethyl acetate and the organic phase is washed successively with 100 cm3 of saturated sodium hydrogen carbonate solution and with 100 cm3 of saturated sodium chloride solution
4. dry with materialdried over magnesium sulphate
5. filtrationfiltered
6. concentrationconcentrated to dryness
7. customto give 500 mg of crude product, which
8. customis purified by chromatography under an argon pressure of 50 kPa
9. washon a column of silica gel (particle size 40-60 μm; diameter 4.5 cm), eluting with ethyl acetate
10. additionThe fractions containing the expected product
11. customthe solid is triturated in 20 cm3 of diethyl ether
12. filtrationfiltered off
13. washwashed with 2×5 cm3 of diethyl ether
14. customdried (90 Pa; 45° C.)