Uses
5,6-Dichloropyridin-3-ol is a useful research chemical used in the preparation of bi- or tricyclic heterocycles with sulfur containing substituents as pesticides.
Synthesis
General procedure for the synthesis of 2,3-dichloro-5-hydroxypyridine from 5,6-dichloropyridin-3-yl acetate: an aqueous solution (7 mL) of potassium hydroxide (KOH, 728 mg, 13 mmol) was slowly added to an aqueous solution (7 mL) of tetrahydrofuran (THF, 10 mL) of 5,6-dichloropyridin-3-yl acetate (1 g, 4.8 mmol) at 0 °C. After the addition was completed, the reaction mixture was stirred for 2 h at room temperature. Subsequently, the pH of the mixture was adjusted to a weak base with dilute hydrochloric acid and filtered. The filtrate was purified by recrystallization to afford the target product 2,3-dichloro-5-hydroxypyridine (517 mg, yield: 65%). The structure of the product was confirmed by 1H NMR (400 MHz, DMSO-d6) with chemical shifts δ (ppm) of 7.47 (d, 1H), 7.93 (d, 1H), 10.72 (s, 1H).
References
[1] Synthesis, 1990, # 6, p. 499 - 501
[2] Patent: WO2016/91731, 2016, A1. Location in patent: Page/Page column 140
[3] Patent: US6432880, 2002, B1
[4] Patent: US6133253, 2000, A
[5] Tetrahedron Letters, 2013, vol. 54, # 19, p. 2303 - 2307
