5-nitro-3-phenylsulfanyl-1-(2-trimethylsilanylethoxymethyl)-1H-indazole → 5-amino-3-phenylsulfanyl-1-(2-trimethylsilanylethoxymethyl)-1H-indazole

HRID 25442Notes

Reaction equation

HRID 25442 reaction equation
[N+:1]([C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[N:9]([CH2:13][O:14][CH2:15][CH2:16][Si:17]([CH3:20])([CH3:19])[CH3:18])[N:8]=[C:7]2[S:21][C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1)([O-])=O>C(OCC)(=O)C.[Pd]>[NH2:1][C:4]1[CH:5]=[C:6]2[C:10](=[CH:11][CH:12]=1)[N:9]([CH2:13][O:14][CH2:15][CH2:16][Si:17]([CH3:20])([CH3:18])[CH3:19])[N:8]=[C:7]2[S:21][C:22]1[CH:27]=[CH:26][CH:25]=[CH:24][CH:23]=1

Participants

4

Reactant 1

HCID 225671635-nitro-3-phenylsulfanyl-1-(2-trimethylsilanylethoxymethyl)-1H-indazole

Product 1

HCID 225672675-amino-3-phenylsulfanyl-1-(2-trimethylsilanylethoxymethyl)-1H-indazoleYield 89.2%

Reagents, catalysts & solvents 2

HCID 23938PalladiumCatalystHCID 8857Ethyl AcetateSolvent

Procedure

5-Amino-3-phenylsulfanyl-1-(2-trimethylsilanylethoxymethyl)-1H-indazole can be obtained in the following way: a solution of 0.4 g of 5-nitro-3-phenylsulfanyl-1-(2-trimethylsilanylethoxymethyl)-1H-indazole in 16 ml of ethyl acetate containing 40 mg of 10% palladium-on-charcoal is hydrogenated under a pressure of 200 kPa at a temperature in the region of 25° C. for 18 hours. After filtration of the catalyst through Celite® under argon and washing with ethyl acetate, the filtrate is concentrated to dryness under reduced pressure (2 kPa) at a temperature in the region of 25° C. 0.33 g of crude 5-amino-3-phenylsulfanyl-1-(2-trimethylsilanylethoxymethyl)-1H-indazole is thus obtained in the form of a burgundy-colored oil. A second attempt using 1.1 g of 5-nitro-3-phenylsulfanyl-1-(2-trimethylsilanylethoxymethyl)-1H-indazole makes it possible to obtain, in the same way, 0.99 g of crude 5-amino-3-phenylsulfanyl-1-(2-trimethylsilanylethoxymethyl)-1H-indazole in the form of a burgundy-colored oil. The two crude products are pooled and purified by chromatography under argon pressure (50 kPa), on a column of 53 g of silica (particle size 40-63 μm), eluting successively with pure cyclohexane then with cyclohexane/ethyl acetate (97/3; 95/5; 90/10; 80/20 by volume) mixtures. The fractions containing the expected product are pooled and concentrated to dryness under reduced pressure (2 kPa) at a temperature in the region of 30° C. 0.78 g of 5-amino-3-phenylsulfanyl-1-(2-trimethylsilanylethoxymethyl)-1H-indazole is thus obtained in the form of a burgundy-colored oil (EI mass analysis: m/z 371 (M+) (base peak)).

Workup

  1. filtrationAfter filtration of the catalyst through Celite® under argon
  2. washwashing with ethyl acetate
  3. concentrationthe filtrate is concentrated to dryness under reduced pressure (2 kPa) at a temperature in the region of 25° C

Sources & evidence

ORD record
ord-05464f2d84a345fabc96eb73aaa42a8e
Source dataset
uspto-grants-2005_02
Patent number
US06858638B2

Reaction notes

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