7-bromo-[1,2,4]triazolo[1,5-a]pyridin-2-amine

A mixture of hydroxylamine hydrochloride (20.0 g, 288 mmol) and N-ethyldiisopropylamine (30.1 ml, 173 mmol) in ethanol (367 ml) is stirred for a few minutes at room temperature and the mixture is added to l-ethoxycarbonyl-3-(4-bromo-pyridin-2-yl)-thiourea (17.5 g, 57.5 mmol). The resulting mixture is refluxed for 1 day. The solvent is evaporated and 100 ml water is added to the residue. The suspension is stirred for 10 minutes, the solid is collected by filtration, washed with water and dried affording 7-bromo-[l, 2, 4]triazolo[l, 5-a]pyridin-2-amine (10.71 g, 87.4percent) as a light yellow solid. Mp.: 190-2°C. MS: m/z= 213.0, 215.0 (M+HTo a stirred suspension/solution of hydroxylamine hydrochloride (375 mg, 5.40 mmol) and diisopropylethylamine (419 mg, 3.24 mmol) in MeOH/EtOH (1 :1 , 2 mL) was added compound 2 as a solid. This mixture was stirred at room temperature for 2 h, giving a pale yellow suspension, followed by a further 3h, at 602.2 7-Bromo-[l, 2, 4]triazolo[l, 5-a]pyridin-2-ylamine (3); To a suspension of hydroxylamine hydrochloride (4.7g, 68mmol) in EtOH/MeOH (1 :1, 16OmL) was added JV, jV-diisopropylethylamine (7.2mL, 41mmol), the mixture was stirred at room temperature (2Ob)10.61 g (152.677 mmol) of hydroxylamine hydrochloride and 11.84 g (91.606 mmol) N, N- diisopropylamine were dissolved in 60 ml methanol/ethanol (v/v = 1 :1). B-6 g (28.273 mmol) of the compound from example 109A was added and the mixture was stirred at room temperature for 2 h and at 60To a solution of 2-amino-4-bromopyridine (5.0 g, 28.90 mmol) in dichloromethane (120 mL) at 0 °C, was added ethoxycarbonyl-isothiocyanate (3.41 mL, 28.90 mmol) dropwise for 30 min and stirred at room temperature for 12 h. The solvent was evaporated in vacuo to leave a yellow solid which was triturated with hexane, filtered and air dried. The crude was taken to the next step without any further purification. To a suspension of hydroxylamine hydrochloride (3.61 mL, 86.68 mmol) in a mixture of EtOH/MeOH (1:1, 200 mL) was added N, N-diisopropylethylamine (25 mL, 144.50 mmol) and the mixture was stirred at room temperature for 2 h. The compound 1-(6-bromo-pyridin-2-yl)-3-carboethoxythiourea which was isolated in the previous step was then added and the mixture was slowly heated to 60 °C and stirred for 3 h. The reaction mixture was cooled, and the precipitated solid was filtered. The solid was washed with a mixture of EtOH/MeOH (1:1, 25 mL) followed by diethyl ether (15 mL) and air dried to afford the title compound as white solid. Yield: 65percent (4.00 g) (adapted from

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