2-AMINO-6-BROMOPYRIDIN-3-OL

A mixture of 6-bromo-2-nitro-pyridin-3-ol (3 g, 13.7 mmol), Fe (7657.88 mg, 136.99 mmol) and NHCompound I-2 (1 g, 4.6 mmol) was added to a three-necked flask, Dissolved with 20 mL of ethanol, After replacing the nitrogen three times, To this was added zinc dust (1.5 g, 22.9 mmol) andAmmonium chloride (2.46 g, 46 mmol), Replace nitrogen again;50 under the conditions of reaction 16h, (CH2Cl2: CH3OH = 25: 1). The reaction solution was filtered and the filtrate was collected. After concentration under reduced pressure, the residue was purified by petroleum ether / ethyl acetate (5: 1)The grayishl solid was the target product I-3 (524 mg, 60percent).Under an atmosphere of nitrogen, zinc powder (1.5 g, 22.9 mmol) and NH4Cl (1.5 g, 22.9 mmol) were added to the solutionof 2-nitropyridin-3-ol (17) (1 g, 4.6 mmol) in C2H5OH (20 mL).The reaction was heated to 50 C and stirred for 16 h. The crudereaction mixture was filtered and purified by flash column chromatography(PE:EA 5:1) to provide the title compound 6-bromo-2-nitropyridin-3-ol (18) (524 mg, 60percent). 1H NMR (400 MHz, DMSO)d 9.70 (s, 1H), 6.74 (d, J 7.8 Hz, 1H), 6.49 (d, J 7.8 Hz, 1H), 5.91 (s, 1H); MS (M H): m/z 188.99.To a stirred solution of 6-bromo-2-nitropyridin-3-ol (6 g, 27.40 mmol) in EtOH (100 mL) was added iron (11.00 g, 197.00 mmol), calcium chloride (3.04 g, 27.4 mmol) and the reaction mixture for was heated at 85 °C for 16 h. The reaction mixture was cooled to ambient temperature, filtered through celite and the filtrate was evaporated under reduced pressure. The residue was purified by column chromatography (Redisep-80 g, 10-20percent MeOH/DCM) to obtain Intermediate 115A (3.00 g, 57.90percent) as a yellow solid.Triethyl orthoacetate (CAS: 78-39-7; 4.82 mL, 26.48 mmol) was added to a stirred mixture of A mixture of 2-amino-6-bromo-pyridin-3-ol (2.5 g, 13.23 mmol) and CDI (2.24 g, 15.87 mmol) in THF (100 mL) was stirred at 55 C for 16 hours. The reaction solution was cooled to room temperature and concentrated to give the crude product. The crude product was purified by flash chromatography on silica gel (EtOAc in PE = 10% to 30% to 50%) to give the product (900 mg, 4.18 mmol, 32% yield) as a solid. 1H NMR DMSO-c 400MHz deltaH = 12.68 (s, 1H), 7.62 (d, 1H), 7.33 (d, 1H).

Molecular Weight:189.01
XLogP3:1.2
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:3
Exact Mass:187.95853
Monoisotopic Mass:187.95853
Topological Polar Surface Area:59.1
Heavy Atom Count:9
Complexity:101
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes