5-Aminooxindole

356 mg of 5-nitro-1, 3-dihydro-indol-2-one is hydrogenated in 30 ml of tetrahydrofuran:ethanol=1:1 with 400 mg palladium on carbon (10percent) at room temperature and normal pressure for 1 hour. Example 159b To a suspension of 5-nitroindolin-2-one (5 g, 1 eq.) in EtOH(50 mL), activated carbon (1 g) and FeCl3 (1 g) were added.The mixture was heated to 78 °C, and stirred for 10 min.Then 80percent aqueous solution of hydrazine hydrate (8 eq.)was added dropwise into the reaction mixture in 5 min, theresulting mixture was stirred at 78 °C for 8–10 h, thencooled to room temperature. The mixture was filtered to remove residue of activated carbon; the filtrate was concentratedunder vacuum to afford crude product, which waspurified by recrystallization from EtOH (about 15 mL) togive 5-aminoindolin-2-one as a pale yellow solid (yield91.9percent).The commercial 5-nitroindolin-2-one (1.00 g, 5.61 mmol) was hydrogenated in EtOH (70 mL) in the presence of 10percent Pd-C (315 mg, 2.97 mmol) for 4 h. The 5-nitro-2-oxindole 1 (1 .00 g, 5.61 mmol) was hydrogenated in EtOH (70 mL)in the presence of 10percent Pd-C (315 mg, 2.97 mmol) for 4h at room temperature.Then the catalyst was filtered off through Celite, the Celite rinsed with additional EtOH and the solution was evaporated, to give 2 as a brown solid (698 mg, 4.71 mmol, 84percent yield).1HNMR (400 MHz, DMSO-d6): 6 3.30 (5, 2H, CH2); 4.62 (br s, 2H, NH2); 6.37(dd, 1H, J= 2.2, 8.2 Hz, Ar); 6.48-6.50 (m, 2H, Ar); 9.90 (br s, 1H, NH) ppm.Anal. Calcd for C8H8N20: C, 64.85percent; H, 5.44percent; N 18.91percent; Found: C, 65.03percent;H, 5.49percent; N, 18.83percentTo 250 mL acetic acid was added 7.00 g (39.3 MMOL) 5-nitro-1, 3-dihydro-indol-2-one and 418 mg (0.393 MMOL) palladium on carbon. Exposed the reaction mixture to 40 psi H2 on parr shaker for 1.5 hours. The reaction was filtered through diatameceous earth, and the acetic acid was removed under reduced pressure. Cooled the reaction mixture to 0 C and added 10.0 mL of a 94.5 : 5: 0.5 CHC13 : CH30H: NH40H solution. The solution was loaded onto a silica gel column and purified via chromatography (97.8 : 2.0 : 0.2 CHCI3 : CH30H: NH40H) to give a white solid which was further crystallized using the eluent as the solvent to give 4.06 G (27.2 mmol, 69percent) of the title compound as crystalline white needles. C8H9N20 :Step 2 5-Nitro-1, 3-dihydro-indol-2-one 30b (3.56 g, 20 mmol) was dissolved in 200 ml of acetic acid under stirring, and added with palladium on activated carbon (1.0 g, 5percent) to the solution at room temperature. The reaction mixture was stirred under a hydrogen atmosphere. After thin lay chromatography showed the disappearance of starting materials, the reaction mixture was filtered, and concentrated under reduced pressure to obtain the title compound 5-amino-1, 3-dihydro-indol-2-one 30c (2.04 g, yield 68.9percent) as a white solid. MS m/z (ESI): 149.4[M+1]5-Amino-2-oxindole 5-Amino-2-oxindole Preparation of 5-amino-oxindole (2) To a solution of 5-nitro-oxindole (25 g) in 120 mL of dimethylacetamide in a Parr bottle was added 10percent Pd/C (0.5 g). The mixture was hydrogenated (40 psi H2) for 16 hours. The catalyst was removed by filtration and the filtrate was diluted with ether (2 L) to provide 5-amino-oxindole (10.5 g; 50percent).EXAMPLE 6 To the above compound (4.139 g, 12.3 mM) dissolved in acetic acid (70 ml) was added portionwise under stirring zinc dust (5.884 g, 90 mM) at 0-5° C. and the mixture was stirred for another 1 h. The mixture was filtered on a pad of celite, the pad washed with ethylacetate, the separated organic layer washed with 5percent sodium bicarbonate solution and brine, dried and evaporated to dryness to give raw Reduction of this compound with 10 equivalents of zinc dust in 80 ml of acetic acid at room temperature for 3h gave General procedure: The reaction of The mixture of Thereaction of General procedure: The mixture of

Molecular Weight:148.16
XLogP3:0.5
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:2
Exact Mass:148.063662883
Monoisotopic Mass:148.063662883
Topological Polar Surface Area:55.1
Heavy Atom Count:11
Complexity:181
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes