5-Bromobenzotriazole

To a solution of 4-bromobenzene-1, 2-diamine (10 g, 53.5 mmol) in a mixture of acetic acid (20 ml, 349 mmol) and water (100 ml) at 0-5° C. was added a solution of sodium nitrite (4.06 g, 58.8 mmol) in water (10 ml) dropwise. Stirred in the ice bath for 1 h, more acetic acid (20 ml, 349 mmol) was added, heated to 80-85° C. with stirring during 1 h, the solution was filtered hot to remove insoluble black material, cooled to 0-5° C., aged for 30 min, precipitate collected, washed with water, dried in vacuum at 45° C. Yield 9.48 g (90percent).A 250 mL four-necked flask equipped with a mechanical stirrer, thermometer, reflux condenser, nitrogen inlet and bubble counterEach o-diaminobenzene (0.031 mol) (Formula 1a) was added dropwise to glacial acetic acid (50 mL) under a nitrogen atmosphere.The resulting slurry was cooled to 4 [deg.] C in an ice-bath. Sodium nitrite in water (6 mL) (2.24 g, 0.032 mol) in THF Was added dropwise over 40 minutes while maintaining the temperature of the reaction mixture below & lt; RTI ID = 0.0 & gt; 10 C. & lt; / RTI & gt; GeneratedThe slurry was allowed to warm to room temperature and analyzed using a KI / amylose test paper until analysis for free HNO2 was negative and starting material was not visible in thin layer chromatography (16 h)Under stirring. The resulting slurry was filtered; the solid residue washed with water (100 mL) and the resulting solid was further purified by recrystallization from ethanol (20 mL). The product was dried for 24 h at 50° C. and 5 mbar and obtained as off-white solid. Yield: 67percent.To a solution of 4-bromobenzene-1, 2-diamine (10 g, 53.5 mmol) in a mixture of acetic acid (20 ml, 349 mmol) and water (100 ml) at 0-5 C. was added a solution of sodium nitrite (4.06 g, 58.8 mmol) in water (10 ml) dropwise. Stirred in the ice bath for 1 h, more acetic acid (20 ml, 349 mmol) was added, heated to 80-85 C. with stirring during 1 h, the solution was filtered hot to remove insoluble black material, cooled to 0-5 C., aged for 30 min, precipitate collected, washed with water, dried in vacuum at 45 C. Yield 9.48 g (90%).A 250 mL four-necked flask equipped with a mechanical stirrer, thermometer, reflux condenser, nitrogen inlet and bubble counterEach o-diaminobenzene (0.031 mol) (Formula 1a) was added dropwise to glacial acetic acid (50 mL) under a nitrogen atmosphere.The resulting slurry was cooled to 4 [deg.] C in an ice-bath. Sodium nitrite in water (6 mL) (2.24 g, 0.032 mol) in THF Was added dropwise over 40 minutes while maintaining the temperature of the reaction mixture below & lt; RTI ID = 0.0 & gt; 10 C. & lt; / RTI & gt; GeneratedThe slurry was allowed to warm to room temperature and analyzed using a KI / amylose test paper until analysis for free HNO2 was negative and starting material was not visible in thin layer chromatography (16 h)Under stirring. The resulting slurry was filtered; the solid residue washed with water (100 mL) and the resulting solid was further purified by recrystallization from ethanol (20 mL). The product was dried for 24 h at 50 C. and 5 mbar and obtained as off-white solid. Yield: 67%.Example 248B Example 248B General procedure: A solution of 10 mmol of the appropriate benzene-1, 2-diamine in3.5 mL of acetic acid (AcOH) and 1 mL of water was cooled to 0-5 C, followed by the addition of 15 mmol of sodium nitrite in 2 mL ofwater. The mixture was stirred for 2 h at room temperature. Afterthe completion of the reaction, a solventwas evaporated and the residuewasco-evaporatedwith toluene (3 × 20mL). The crude productwas partitioned between water (20 mL) and ethyl acetate (20 mL), the organic phase was washed with the saturated solution of sodiumhydrogen carbonate and dried overmagnesiumsulfate (MgSO4). Theproducts were purified by crystallization from nitromethane and/orby column chromatography on silica gel using a chloroform - methanol97:3-95:5 v/v mixture as eluent. Reaction products were analyzedby use of mass-spectrometry (Waters Q-TOF Premier MassSpectrometer) and NMR spectroscopy (Varian INOVA 500 Spectrometer, see Supp. Fig. 1). Purity of the products was assessed using internalstandard quantitative NMR method (qNMR) [49]. It shouldbe noted that the formal qNMR-derived purity determined for 4-BrBt, 4-ClBt, 5, 6-Cl2Bt and 5, 6-Br2Bt increased significantly upon additiona small amount of water to the DMSO solution, which increasedproton exchange rates. This observation indicates that thenuclear relaxation process accompanying protomeric equilibrium(generally N1-H and N3-H forms predominates) significantly contributeto the obtained NMR spectra, the best proof of which is thestrong broadening of the H-7 resonance line in 4-BrBt and 4-ClBt(Supp. Fig. 1A, B).

Molecular Weight:198.02
XLogP3:1.7
Hydrogen Bond Donor Count:1
Hydrogen Bond Acceptor Count:2
Exact Mass:196.95886
Monoisotopic Mass:196.95886
Topological Polar Surface Area:41.6
Heavy Atom Count:10
Complexity:130
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes