76041-71-9Relevant articles and documents
A for the synthesis of anti-cancer auxiliary drug pyridine medical process for the preparation of intermediates
-
Paragraph 0025, (2017/01/26)
The invention relates to the field of medical chemistry and discloses a method for synthesizing a pyridine medical intermediate, namely 2-bromo-3-chloro-5-trifluoromethyl pyridine, for synthesizing anti-cancer auxiliary medicines. The method comprises the following steps of: (1) reacting 6-hydroxynicotinic acid, hydrofluoric acid and sulfur tetrafluoride at the temperature of between 100 and 120DEG C and under the pressure of 0.1-0.3MPa, and adding water to obtain 2-hydroxy-5-trifluoromethyl pyridine; (2) reacting with N-chlorosuccinimide, and performing water precipitation to obtain 3-chloro-5-trifluoromethyl-2-hydroxypyridine; and (3) adding excessive phosphorus oxybromide, reacting at the temperature of between 145 and 160DEG C for 5 to 8 hours, cooling, violently stirring at the temperature of between -5 and 0DEG C, extracting, combining organic phases, drying, filtering, performing spin drying, and purifying by using a silica gel column. According to the method, raw materials are readily available, the cost is low, the method is suitable for industrial production and the yield exceeds 38 percent.