Background and overview[1]
4-Amino-2,6-difluorophenol can be used as a pharmaceutical synthesis intermediate. If you inhale 4-amino-2,6-difluorophenol, please move the patient to fresh air; if there is skin contact, take off contaminated clothing, rinse the skin thoroughly with soap and water, and seek medical attention if you feel uncomfortable; If eye contact occurs, separate eyelids, rinse with running water or saline, and seek medical attention immediately; if ingested, rinse mouth immediately, do not induce vomiting, and seek medical attention immediately.
Preparation [1]
The steps for preparing 4-amino-2,6-difluorophenol are as follows: add 2,6-difluoro-4-nitrophenol (1.75g, 10mmol) in a closed vessel under an initial hydrogen pressure of 3.5 bar ) and a solution of 10% palladium/carbon catalyst (0.3g) in ethanol (100ml). When hydrogen absorption was complete, the catalyst was filtered off and the filtrate was evaporated to a solid, triturated with petroleum ether, filtered, washed and dried to give 4-amino-2,6-difluorophenol (1.31 g), m.p. indefinite. Application[1]
4-Amino-2,6-difluorophenol can be used as a pharmaceutical synthesis intermediate. For example, it can be used to prepare the compound 3-butyryl-4-(3,5-difluoro-4-hydroxyphenylamino)-8-methoxyquinoline. The specific steps are: convert 4-amino-2,6-di A solution of fluorophenol (1.49g, 5.65mmol) and 3-butyryl-4-chloro-8-methoxyquinoline (1.23g, 8.48mmol) in dioxane (50ml) was refluxed under nitrogen for 2.5 hours. The solvent was evaporated and the product was converted to the free base and purified by flash chromatography (silica gel, methanol-ammonia/chloroform), triturated with methanol, filtered, washed and dried to give the title compound 3-butyryl-4-(3,5 -Difluoro-4-hydroxyphenylamino)-8-methoxyquinoline (0.58g), m.p. 205°C – 274°C (dec).
Main reference materials
[1] WO1989008105 4-AMINO-3-ACYLQUINOLINE DERIVATIVES AND THEIR USE AS INHIBITORS OF GASTRIC SECRETION
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