2-AMINO-3-BROMOPHENOL

Step B: A mixture of compound B112 (1.00 g, 5.32 mmol) in 1, 1, 1 -triethoxy ethane (4.40 g, 27.1 mmol) was stirred at 120C under N2 for 2 hours to form a black red solution. LCMS showed 91.7% of desired MS. Most of MeC(OEt)3 was removed under reduced pressure to give compound B113 (950 mg) as a red powder.General procedure: A 25 mL RB was charged with a mixture of 2-aminophenols 1a-h (1.0 mmol) or 1-amino-2-naphthol 4a (1.0 mmol) or 2-aminothiophenol 6a (1.0 mmol) or o-phenylenediamine 7a (1.0 mmol) and benzyl alcohols 2a-e, g-j or cinnamyl alcohol 2f (1.0 mmol) along with 3-nitropyridine (0.1 mmol, 12.4 mg), NaOtBu (1.0 mmol, 96 mg) and DMSO (2 mL). The RB was loosely fitted with septum and then heated at 110 C for 16 h. After completion of the reaction, the mixture was diluted with hot ethyl acetate (20 mL) and water (40 mL) and extracted with ethyl acetate (3 10 mL). The combined organic layer was washed with brine (2 10 mL) and dried over anhydrous Na2SO4. Solvent was removed under reduced pressure and the remaining residue was purified by flash chromatography over silica gel using hexane / ethyl acetate = 9:1 (v/v) as an eluent to obtain the desired products benzoxazoles 3a-v, naphthoxazoles 5a-f, benzothiazoles 8a-f and benzimidazoles 9a-c in high yields.General procedure: A 25 mL RB was charged with a mixture of 2-aminophenols 1a-h (1.0 mmol) or 1-amino-2-naphthol 4a (1.0 mmol) or 2-aminothiophenol 6a (1.0 mmol) or o-phenylenediamine 7a (1.0 mmol) and benzyl alcohols 2a-e, g-j or cinnamyl alcohol 2f (1.0 mmol) along with 3-nitropyridine (0.1 mmol, 12.4 mg), NaOtBu (1.0 mmol, 96 mg) and DMSO (2 mL). The RB was loosely fitted with septum and then heated at 110 C for 16 h. After completion of the reaction, the mixture was diluted with hot ethyl acetate (20 mL) and water (40 mL) and extracted with ethyl acetate (3 10 mL). The combined organic layer was washed with brine (2 10 mL) and dried over anhydrous Na2SO4. Solvent was removed under reduced pressure and the remaining residue was purified by flash chromatography over silica gel using hexane / ethyl acetate = 9:1 (v/v) as an eluent to obtain the desired products benzoxazoles 3a-v, naphthoxazoles 5a-f, benzothiazoles 8a-f and benzimidazoles 9a-c in high yields.General procedure: In a 250 mL single-necked flask, 2-amino-6-bromophenol (25 g, 0.13 mol), benzoic acid (16.25 g, 0.13 mol) and 50 mL of polyphosphoric acid were added and reacted at 160 C for 6 hours.After the reaction was completed, the reaction mixture was cooled to room temperature, washed with water and filtered to obtain a crude product. The crude product was purified by column chromatography to obtain 25.75 g of a white solid in a yield of 70.7%.To (1.0 g, 5.3 mmol) was added to ethyl 2-chloro-2-oxoacetate (1.1 g, 8.0 mmol) in 1, 4-Dioxane (12.0 ml) at room temperature. The reaction solution was stirred for 1 hr at 1500 C under microwave, cooled, and concentrated. The residue was purified by silica gel chromatography, eluting with ethyl acetate/petroleum ether (1/10). The combined organic fractions were concentrated under reduced pressure to give the title compound: LCMS (ESI) calc'd for C, 0H8BrO3 [M + 1]: 270 / 272, found 270 / 272. 'H NMR (400 MHz, CDC13) oe7.64 (dd, J = 8.4 Hz, 2H), 7.42 (dd, J = 8.0 Hz, 1H), 4.60-4.55 (m, 2H), 1.51-1.37 (m, 3H).

Molecular Weight:188.02
XLogP3:1.6
Hydrogen Bond Donor Count:2
Hydrogen Bond Acceptor Count:2
Exact Mass:186.96328
Monoisotopic Mass:186.96328
Topological Polar Surface Area:46.2
Heavy Atom Count:9
Complexity:99.1
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes