Synthesis
The general procedure for the synthesis of 3-amino-5-bromopyridin-2-one from 5-bromo-2-hydroxy-3-nitropyridine was as follows: a mixture of 5-bromo-3-nitropyridin-2-ol (1.26 g, 4.6 mmol) and tin chloride dihydrate (3.91 g, 17.3 mmol) in ethyl acetate (19.3 mL) was heated and reacted for 20 hours at 50 °C. After completion of the reaction, the mixture was cooled to room temperature, diluted with ethyl acetate (100 mL) and washed with saturated saline. After separation of the aqueous layer, the aqueous layer was extracted several times with ethyl acetate (5 x 50 mL). All organic layers were combined, dried with anhydrous sodium sulfate, filtered and concentrated under reduced pressure to give 580 mg (53% yield) of the black solid product 3-amino-5-bromopyridin-2-one, which can be used directly in subsequent reactions without further purification.
References
[1] Patent: US2005/256137, 2005, A1. Location in patent: Page/Page column 10
[2] Yakugaku Zasshi, 1951, vol. 71, p. 169,172
[3] Chem.Abstr., <1952> 8108,
[4] Chemical and Pharmaceutical Bulletin, 1959, vol. 7, p. 720,724
[5] Indian Journal of Chemistry - Section B Organic and Medicinal Chemistry, 1999, vol. 38, # 9, p. 1036 - 1040
