Synthesis
The general procedure for the synthesis of 4-bromo-3-hydroxypyridine from the compound (CAS: 98976-81-9) is as follows: to a solution of 4-bromo-3-pyridinyl diethylcarbamate (1.24 g, 4.50 mmol) in methanol (10 mL) was added methanolic solution of sodium methanolate (2.04 g, 9.40 mmol) at 20°C and the resulting mixture was refluxed for 1.5 hours. Upon completion of the reaction, methanol was removed by distillation under reduced pressure, ethyl acetate (15 mL) and water (1 mL) were added, and then the pH was adjusted to 9 with 20% aqueous sulfuric acid. the organic layer was separated, and the residue was washed with ethyl acetate (3 x 5 mL). The organic layers were combined, dried and concentrated with anhydrous sodium sulfate. The crude product was purified by rapid chromatography on silica gel, eluting sequentially with hexane/ethyl acetate (1:1 and 1:2) to give 691 mg (89% yield) of 4-bromo-3-hydroxypyridine.TLC Rf value was 0.38 (1:2 hexane/ethyl acetate). Mass spectra (DCI/NH3) m/e 174 (with 79 Br) and 176 (M+H)+ (with 81 Br).1H NMR (CDCl3, 300 MHz) δ: 8.43 (d, J=1.5 Hz, 1H, ArH), 8.02 (d, J=7.2 Hz, 1H, ArH), 7.54 (dd, J=7.2,1.5 Hz. 1H, ArH).
References
[1] Patent: US5914328, 1999, A
[2] Patent: US5948793, 1999, A
