| 摘要 |
1,255,153. Fluoropyridines. IMPERIAL CHEMICAL INDUSTRIES Ltd. 16 Sept., 1969 [30 -Sept., 1968], No. 46315/68. Heading C2C. 3,5 - Dichloro - 2,6 - difluoro - 4 - hydroxypyridine and salts thereof are prepared by reaction of 3,5 - dichloro - 2,4,6 - trifluoropyridine with aqueous sodium or potassium carbonate or bicarbonate to form the sodium or potassium salt, followed by acidification to form the free 4-hydroxy compound, together with the tautomeric 3,5-dichloro-2,4-difluoro- 6-pyridone, followed if desired by salification. |
