5-Bromo-1,3-benzenediol

General procedure: 2-(Methoxymethyl)-5-methyl-3-(m-tolyl)pyrrolo[2, 1-f][1 , 2, 4]triazin-4(3H)-one (1 .56 g, 4.85 mmol) was dissolved in 150 mL dichloromethane and cooled at 0°C with an ice bath. A solution of boron tribromide (1 M, 24.2 mL, 24.2 mmol) was added dropwise and the reaction mixture was stirred at room temperature overnight. The organic was washed with 4percent solution of sodium bicarbonate, brine and dried over sodium sulphate, filtered and concentrated under reduced pressure to obtain 1 .75 g of the desired product as a dark oil. 1-Bromo-3, 5-dimethoxybenzene (5 g, 23 mmol) was treated with a solution of boron tribromide (1 M, 1 15 ml, 1 15 mmol) according to the method of Preparation 20. The crude was purified by reverse phase to give 4.35 g (98percent yield) of the title compound as a solid. Purity 99percent. LRMS (m/z): 190 (M+1 )Example 28 Synthesis of 1-Bromo-3, 5-dihydroxybenzene (33) [0118] 1-bromo-3, 5-dimethoxybenzene (32) (1.00 g, 4.60 mmol) was dissolved in dry dichloromethane (40 ml) and cooled in an ice bath. Boron tribromide (1.33 ml, 13.82 mmol) was added and the mixture was stirred on 2 h. The mixture was allowed to warm up to room temperature and stirred overnight. Methanol (1.4 ml) was added drop-wise to terminate the reaction, and the mixture was poured into water (50 ml) and stirred at RT for 2 h. Reaction mixture was neutralized with NaHCOStep 1: In a clean dry round bottom flask, l-bromo-3.5-dimethoxybenzene (8.00 g, 36.9 mmol) was added to 300 ml of dry dichloromethane. The solution was cooled down to 0°C and ΒΙ (25.00 g, 100 mmol) was added dropwise. After 2 hours, the mixture was allowed to warm to room temperature and stirred over night. Methanol (10 ml) was added dropwise to terminate the reaction. The mixture was poured into water and stirred for 2 hours. Then saturated sodium bicarbonate (100 ml) was added and extracted with ethyl acetate. The organic layer was washed with saturated sodium bicarbonate, brine and then dried over NaTo a dichloromethane solution (300 mL) of 1-bromo-3.5-dimethoxaybenzene (8.00 g, 36.9 mmol) in ice bath was added BBr3 (25.00 g, 100 mmol) dropwise. After 2 hours, themixture was allowed to warm to room temperature and stirred over night. Methanol (10 mL) was added dropwise to terminate the reaction. The mixture was poured into water and stirred for 2 hours, then saturated sodium bicarbonate (100 mL) was added and extracted with dichloromethane. The organic layer was washed with saturated sodium bicarbonate, brine, and then dried over Na2SO4 The residue, after concentration, was purified using chromatography(eluent: methoh/DCM: 2/98, v/v). A white solid (1.0 g) was obtained as product. LC-MS and HNMR are nice.A. To a solution of 1-bromo-3, 5-dimethoxybenzene (15.0 g, 69.0 mmol)CH2CI2 (40 mL) at 0°C under argon was added dropwise a 1 M BBr3 solution in CH2CI2 (140 mL, 140 mmol). The ice bath was removed and the reaction was stirred at room temperature for 18 h. The reaction was quenched with MeOH and concentrated. The residue was dissolved in EtOAc (500 mL) and washed with water (300 mL). The organic layer was separated, dried (Na2504) and concentrated to give 5- bromobenzene-1, 3-diol (13.03 g, 69.0 mmol) as an orange oil.General procedure: To a magnetic solution of aromatic compound (1 mmol)in acetonitrile (5 mL), OXBTEATB (0.233 g, 0.5 mmol) wasadded and stirred at room temperature for the appropriatetime (Table 1). The reaction was monitored by TLC (eluent:n-hexane/ethyl acetate: 5/1). The reaction mixture was transferredinto a separatory funnel after filtration of OXBTEABand was extracted with water (15 mL) and dichloromethane(20 mL). The organic layer was dried over anhydrousNa2SO4, and the solvent was concentrated in a rotary evaporator.The crude product was purified by passing it over acolumn of silica gel using a mixture of n-hexane and ethylacetate as the eluent. In order to regenerate the reagent, whitesolid was treated with liquid bromine. All the product structureswere confirmed by comparison of melting point or 1HNMR spectra with ones reported in the literature [29a-29e].

Molecular Weight:189.01
XLogP3:1.2
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:2
Exact Mass:187.94729
Monoisotopic Mass:187.94729
Topological Polar Surface Area:40.5
Heavy Atom Count:9
Complexity:87.1
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes