1-BENZYL-5-NITRO-1H-INDAZOLE

General procedure: A mixture of 3-amino-1-methyl-1H-indazole 2 (3.0 mmol) and tert-butyl nitrite (1.0 mL, 8.1 mmol, 2.7 equiv) in THF (12.0 mL) was heated to reflux for 1 h. The mixture was cooled to rt and then concentrated. H2O (10.0 mL) and EtOAc (20.0 mL) were added to the residue. The organic layer was washed with H2O (10.0 mL), brine (10.0 mL), dried over Na2SO4, filtered, and concentrated in vacuo. The residue was subjected to silica-gel chromatography by using Et2O/hexanes (1:4) as eluent to give the product 3.#10;To a solution of 5-nitroindazole (10.0 g, 61.3 MMOL) in acetonitrile (100 mL) was added potassium carbonate (16.9 g, 122.6 MMOL) and benzyl bromide (13.6 g, 79.7 MMOL). The resulting yellow reaction mixture was heated with stirring at 70°C overnight. Upon cooling down, the solid was filtered off and washed with methylene chloride. The filtrate was concentrated to dryness and the resulting residue was purified by flash chromatography eluting with 17-25percent ethyl acetate in hexanes (v/v) yielding 7.0 g (44percent) of the corresponding 1-Benzyl-5-nitro-1 H-indazole as a yellow solid. 7.61g (136 MMOL, 5 equiv) of Iron powder (4.03 g, 72.1 MMOL) was added slowly to the solution of 1-BENZYL-5-NITRO-1 H-INDAZOLE (6. 9 g, 27.2 MMOL) in acetic acid (200 mL). After stirring at room temperature overnight, the reaction mixture became milky with formation of a white precipitate. The precipitate was filtered off and the filtrate was concentrated to ca. 20 mL. The residue was diluted with water (200 mL) and neutralized by slow addition of sodium hydroxide. The mixture was then extracted with ethyl acetate (500x5 mL). The organic layer were combined, dried over sodium sulfate, filtered and concentrated to dryness to afford 1-BENZYL-1 H-INDAZOL-5-YLAMINE (5.23 g, 82percent) as a brown SOLID. H NMR (DMSO-D6) : 8 7.72 (s, 1H), 7.35 (d, J=8.8 Hz, 1H), 7.24-7. 14 (m, 5H), 6.74 (m, 2H), 5.49 (s, 2H), 4.80 (br, 2H). ES-LCMS: RT = 0.93 min; [M+H] + = 224.2.

Molecular Weight:253.26
XLogP3:3
Hydrogen Bond Acceptor Count:3
Rotatable Bond Count:2
Exact Mass:253.085126602
Monoisotopic Mass:253.085126602
Topological Polar Surface Area:63.6
Heavy Atom Count:19
Complexity:325
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes