* All experimental methods are cited from the reference, please refer to the original source for details. We do not guarantee the accuracy of the content in the reference.
Iron (Fe) powder (9.75 g, 0.174 mol, Sigma-Aldrich) was added in portions over a period of 2h to a stirred solution of 2-chloro-3-methyl-5-nitropyridine (10 g, 0.058 mol, Combi-blocks) in acetic acid/water (29 mL: 88 mL). After 3h, the reaction mixture was filtered through celite and the filter cake was washed with ethyl acetate. The organic layer was separated and the aqueous layer was extracted with EtOAc. The combined organic layers were washed with aqueous sodium bicarbonate, brine and dried over Na2S04. The solvent was removed under reduced pressure to yield 6-chloro-5-methylpyridine-3-amine as a brown solid (8.0g; 97percent). MS m/z = 142.03 [M+H]+.1H-NMR (300MHZ, DMSO-d6): 7.54 (d, J=30 Hz, 1H), 6.91-6.90 (dd, J = 0.6 Hz & 2.7 Hz, 1H), 5.39 (s, 2H), 2.17 (s, 3H)
97%
With iron; acetic acid In water for 5 h;
Iron powder (9.75 g, 0.17 mol) was added in portions over a period of 2 h to a stirred solution of 2-chloro-3-methyl-5-nitropyridine (10 g, 58.00 mmol, Combi-blocks) in HOAc/water (29 mL : 88 mL). After 3 h, the reaction mixture was filtered through Celite? filter aid and the filter cake was washed with EtOAc. The organic layer was separated and the aqueous layer was extracted with EtOAc. The combined organic layers were washed with aqueous sodium bicarbonate, brine and dried over Na2SO4. The solvent was removed under reduced pressure to yield 6-chloro-5- methylpyridine-3-amine as a brown solid (269A, 8.00 g; 97percent). MS m/z = 142.03 [M+H]+. 1H-NMR (300MHz, DMSO-d6): 7.54 (d, J=30 Hz, 1 H), 6.91 -6.90 (dd, J = 0.6 Hz & 2.7 Hz, 1 H), 5.39 (s, 2H), 2.17 (s, 3H)
42%
With water; iron; ammonium chloride In methanol at 20 - 50℃; for 3.08333 h; Heating / reflux
Reference Example 33 6-chloro-5-methylpyridine-3-amine; Reduced iron (793 mg) was added to an aqueous solution (25 mL) of ammonium chloride (1.27 g), and the mixture was stirred at room temperature for 5 min. A solution (10 mL) of 2-chloro-3-methyl-5-nitropyridine (816 mg) in methanol was added dropwise over 10 min. The reaction mixture was stirred at 40° C. for 20 min and at 50° C. for 1.5 hr and further refluxed for 1 hr. The reaction mixture was filtered through celite, and celite was washed with methanol. Methanol was mostly removed by concentration under reduced pressure, and saturated aqueous sodium hydrogencarbonate solution was added. The mixture was extracted with ethyl acetate. The extract was washed with saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent: hexane-ethyl acetate=19:1-->7:3) to give the title compound as a solid (yield 280 mg, 42percent). 1H-NMR (CDCl3) δ: 3.62 (2H, br), 6.88-6.89 (1H, m), 7.70-7.71 (1H, m).
42%
With iron; ammonium chloride In methanol at 40℃; for 2.83333 h; Heating
Reference Example 136 6-Chloro-5-methylpyridine-3-amine Reduced iron (793 mg) was added to an aqueous solution (25 mL) of ammonium chloride (1.27 g), and the mixture was stirred at room temperature for 5 min. A solution (10 mL) of 2-chloro-3-methyl-5-nitropyridine (816 mg) in methanol was added dropwise over 10 min. The reaction mixture was stirred at 40°C for 20 min and at 50°C for 1.5 hr and further refluxed under heating for 1 hr. The reaction mixture was filtered through celite, and celite was washed with methanol. Methanol was mostly removed by concentrated under reduced pressure, and saturated aqueous sodium hydrogencarbonate solution was added. The mixture was extracted with ethyl acetate. The extract was washed with saturated brine, dried over anhydrous magnesium sulfate, and concentrated under reduced pressure. The residue was purified by silica gel column chromatography (eluent: hexane-ethyl acetate=19:1→7:3) to give the title compound as a solid (yield 280 mg, 42percent). 1H-NMR (CDCl3)δ: 2.29 (3H, s), 3.62 (2H, br), 6.88-6.89 (1H, m), 7.70-7.71 (1H, m).
19a. 5-Amino-2-chloro-3-methylpyridine 2-Chloro-3-methyl-5-nitropyridine (15 g, 86.9 mmol; from Maybridge Chemical Co.) was dissolved in a solution of H2 O/AcOH (5:1, 60 mL). Iron powder was added to the reaction mixture while maintaining the temperature below 40° C., and the mixture was stirred for 5 hours. The mixture was filtered through celite and the aqueous filtrate was extracted with EtOAc (4*). The filter cake was washed with EtOAc, and the EtOAc solutions were combined, dried (MgSO4), concentrated and chromatographed (silica gel; CHCl3 /MeOH, 98:2) to afford an orange solid (2.3 g, 89percent): 1 H NMR (CD3 OD, 300 MHz) δ2.25 (s, 3H), 7.01 (d, J=2.0 Hz, 1H), 7.58 (d, J=2.0 Hz, 1H); MS (CI/NH3) m/z: 243/245 (M+H)+.
Chemistry
Pharmaceutical Intermediates
Inhibitors/Agonists
Material Science
For Research Only
120K+ Compounds
Competitive Price
1-2 Day Shipping
