8-Bromo-[1,2,4]triazolo[1,5-a]pyridin-2-ylamine

To a sol. of intermediate 50 (55 g, 181 mmol) in EtOH (300 mL) were added MeOH (300 mL), hydroxylamine hydrochloride (62.83 g, 904 mmol) and DIPEA (694 mL, 543 mmol). The r.m. was stirred at r.t. for 6 h. The mixture was concentrated in vacuo and the residue was suspended in DIPE. The precipitate was filtered off. Yield: 37 g of intermediate 51 (96percent yield).Hydroxylamine hydrochloride 180.5 g (2.60 mol) in EtOH / MeOH (1: 1, 1.5 L) was added to the mixed solvent. It was added to N, N-Diisopropylethylamine 271 mL (1.56 mol) the reaction mixture was stirred for 1 hour. 1- (3-Bromo-pyridine-2-yl) -3-carboethoxy-thiourea 158 g was added (0.52 mol) and gradually raise the temperature given by heating under reflux for 3 hours. It cooled to room temperature and the resulting solids were filtered. The filtrate was distilled under reduced pressure and the resulting solids were filtered. Summing the thus obtained solid product washed with purified water, EtOH / MeOH mixture and the solvent n-hexane and dried to give the title compound hunpung 91 g (82percent yield).Hydroxylamine hydrochloride 180.5 g (2.60 mol) in EtOH / MeOH (1:1, 1.5 L) was mixed solvent.It was added to N, N-Diisopropylethylamine 271 mL (1.56 mol) the reaction mixture was stirred for 1 hour.Given the addition of 1- (3-bromo-pyridine-2-yl) -3-carboethoxy-thiourea 158 g (0.52 mol) synthesized in the above and the temperature gradually raised and the mixture was heated under reflux for 3 hours.It cooled to room temperature and the resulting solids were filtered.The filtrate was distilled under reduced pressure and the resulting solids were filtered.Summing the thus obtained solid product washed with purified water, EtOH / MeOH mixture and the solvent n-hexane and dried to give the title compound hunpung 91 g (82percent yield).b) 8-bromo-[1, 2, 4]triazolo[1, 5-a]pyridin-2-amine; Hydroxyl amine (58.5 g, 842 mmol) and N, N-diisopropylethylamine (65.3 g, 86.3 ml, 505 mmol) were dissolved in methanol (200 ml) and ethanol (200 ml). N-(3-bromo-pyridin-2-yl)-N'-ethoxycarbonyl-thiourea (51.2 g, 168 mmol) was added and the reaction mixture was stirred at rt for 1 hour and then at 60° C. for 3 hours.The white precipitate was filtered off and triturated with water for 25 min, filtered and triturated two times with diethylether. The solid was dried by co-evaporation with toluene and dried in vacuum. The title compound was obtained as a white solid (27.9 g, 78percent).MS ISP (m/e): 213.0/215.1 (86/95) [(M+H)Hydroxyl amine (58.5 g, 842 mmol) and N, N-diisopropylethylamine (65.3 g, 86.3 ml, 505 mmol) were dissolved in methanol (200 ml) and ethanol (200 ml). N-(3-bromo-pyridin-2-yl)-N'- ethoxycarbonyl-thiourea (51.2 g, 168 mmol) was added and the reaction mixture was stirred at rt for 1 hour and then at 60°C for 3 hours. The white precipitate was filtered off and triturated with water for 25 min, filtered and triturated two times with diethylether. The solid was dried by co-evaporation with toluene and dried in vacuum. The title compound was obtained as a white solid (27.9 g, 78percent).MS ISP (m/e): 213.0/ 215.1 (86/ 95) [(M+H)b) 8-Bromo-[1, 2, 4]-triazolo[1, 5-a]pyridin-2-amine; Hydroxylamine (58.5 g, 842 mmol) and N, N-diisopropylethylamine (65.3 g, 86.3 mL, 505 mmol) were dissolved in methanol (200 mL) and ethanol (200 mL). N-(3-Bromo-pyridin-2-yl)-N'-ethoxycarbonyl-thiourea (51.2 g, 168 mmol) was added and the reaction mixture was stirred at room temperature for 1 hour and then at 60° C. for 3 hours. The white precipitate was filtered off and triturated with water for 25 minutes, filtered and triturated two times with diethylether. The solid was dried by co-evaporation with toluene and dried in vacuum. The title compound was obtained as a white solid (27.9 g, 78percent).MS ISP (m/e): 213.0/215.1 (86/95) [(M+H)c)To a suspension of DIPEA (128.2 g, 984 mmol) and hydroxylamine hydrochloride (115.1 g, 1.64 mol) in a mixture of ethanol/methanol (400 mL/400 mL) is added 1-(3-bromo-pyridin-2-yl)-3-carboethoxy-thiourea (34a) (105.0 g, 328 mmol). After stirring for 2 h at RT, the reaction mixture is heated under reflux for 18 h. After cooling to RT the precipitate is collected, washed with water and EE and dried to give the product (35a). Yield: 55 g (75percent). LCMS (ESITo a stirred suspension of hydroxylamine hydrochloride (17.4 g, 25.0 mmol) and N , N- diisopropylethylamine (26.0 rnL, 14.9 mmol) in a mixture of methanol (70 mL) and ethanol (70 mL) was added N-(3-bromo-2-pyridinyl)-N'-carboethoxy-thiourea. The mixture was stirred for 2 hours at room temperature then heated to 60To a solution of hydroxylamine hydrochloride (0.10 kg, 1.4 mol, 5.0 equiv) and JV, ./V-diisopropylethylamine (112 g, 0.867 mol, 3.00 eq ) in 1 :1 methanol / ethanol (1.5 L) was added ethyl [(3-bromopyridin-2- yl)carbamothioyl] carbamate (88 g, 0.29 mmol, 1 equiv) in one portion at room temperature. After 2 h, the reaction mixture was warmed to 60 To a stirred suspension of hydroxylamine hydrochloride (about 17 g) and N, N-diisopropylethylamine (about26 mL) in a mixture of methanol (about 70 mL) and ethanol (about 70 mL) is added N-(3-bromo-2-pyridinyl)-N’-carboethoxy-thiourea. The mixture is stirred for about 2 hours at room temperature then heated to about 60°C forabout 18 hours. The suspension is cooled to room temperature, filtered and rinsed with methanol, water thenmethanol. 8-Bromo-[1, 2, 4]triazolo[1, 5-a]pyridin-2-ylamine is isolated as an off-white solid (about 8 g). 1H NMR (400MHz, (D3C)2SO, δ, ppm): 8.58 (d, J=6.4 Hz, 1H), 7.73 (d, J=7.6 Hz, 1H), 6.80 (t, J=7.0 Hz, 1H), 6.25 (s, 2H). MS =213, 215 (MH)+.

Molecular Weight:213.03
XLogP3:1.1
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:3
Exact Mass:211.96976
Monoisotopic Mass:211.96976
Topological Polar Surface Area:56.2
Heavy Atom Count:11
Complexity:154
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes