ChemicalBook CAS DataBase List 1H-INDAZOL-4-AMINE

1H-INDAZOL-4-AMINE synthesis

9synthesis methods

Product Name:1H-INDAZOL-4-AMINE
CAS Number:41748-71-4
Molecular formula:C7H7N3
Molecular Weight:133.15

2942-40-7 Synthesis

2942-40-7
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41748-71-4
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$19.00/250mg

Yield: 100%

Reaction Conditions:

with hydrogen;palladium 10% on activated carbon in ethanol for 4 h;

Steps:

5
Reference Example 5: Indazole-4-Boronate Ester (70): Route 1 EPO (70) (69)To a solution of 2-methyl-3-nitroaniline (2.27g, 14.91mmol) in acetic acid (6OmL) was added a solution of sodium nitrite (1.13g, 1.1 eq.) in water (5mL). After 2 h, the deep red solution was poured onto ice/ water and the resulting precipitate collected by filtration to yield 4-nitro-lH-indazole (67) (1.98g, 81%).A mixture of 4-nitro-lH-indazole (760mg, 4.68mmol), palladium on charcoal (10%, cat.) and ethanol (3OmL) was stirred under a balloon of hydrogen for 4 h. The reaction mixture was then filtered through celite, and the solvent removed in vacuo to yield lH-indazol-4-ylamine (68) (63 lmg, 100%).An aqueous solution of sodium nitrite (337mg, 4.89mmol) in water (2mL) was added dropwise to a suspension of lH-indazol-4-ylamine (63 lmg, 4.74mmol) in 6M hydrochloric acid (7.2mL) at below O⁰C. After stirring for 30 minutes, sodium tetrafluorobrate (724mg) was added to the reaction mixture. A viscous solution resulted, which was filtered and washed briefly with water to yield lH-indazole-4- diazonium tetrafluoroborate salt (69) (218mg, 20%) as a deep red solid.Dry MeOH (4mL) was purged with argon for 5 minutes. To this was added lH-indazole-4-diazonium tetrafluoroborate salt (218mg, 0.94mmol), bis-pinacolato EPO diboron (239mg, l.Oeq.) and [l,r-bis(diphenylphosphino)ferrocene]palladium (II) chloride (20mg). The reaction mixture was stirred for 5 h and then filtered through celite. The residue was purified using flash chromatography to yield the desired title compound (70), (117mg).

References:

PIRAMED LIMITED WO2006/46031, 2006, A1 Location in patent:Page/Page column 31-33