反应详情

Into a 200 ml-volume flask equipped with a thermometer, a stirring unit, a nitrogen inlet and a reflux condenser, 10.4 g (50.0 mmol) of 2,3,5,6-tetrafluoroxylylenediamine synthesized in Example 1, 50 g of water and 9.0 g (150.0 mmol) of acetic acid were charged, and the mixture was stirred at room temperature for 30 minutes. Subsequently, under cooling of the reactor in a water bath, 21.56 g (125.0 mmol) of an aqueous 40 mass % sodium nitrite solution was added dropwise while keeping the inside of the reaction system at 40° C. or less. At the time when about 30% of an aqueous sodium nitrite solution was charged into the reaction system, insoluble components precipitated in the system and vigorous bubbling occurred. Therefore, the dropwise addition of an aqueous sodium nitrite solution was stopped until the bubbling calmed. After the disappearance of bubbling, the dropwise addition of an aqueous sodium nitrite solution was re-started but bubbling was again generated. The operation of re-starting the dropwise addition of sodium nitrite after the disappearance of bubbling was repeated and after 5 hours and 20 minutes, the dropwise addition was completed. The reaction solution obtained was extracted with 10.0 g of methyl ethyl ketone, the organic: phase was washed with 5.0 g of an aqueous 5 mass % sulfuric acid solution, and then the methyl ethyl ketone was removed by distillation, as a result, 8.9 g of 2,3,5,6-tetrafluorobenzenedimethanol was obtained as white crystals. The purity determined from the GC area in percentage was 97.9% and the yield was 82.9%.

1. customInto a 200 ml-volume flask equipped with a thermometer
2. temperatureSubsequently, under cooling of the reactor in a water bath
3. customat 40° C. or less
4. customprecipitated in the system
5. customvigorous bubbling
6. additionTherefore, the dropwise addition of an aqueous sodium nitrite solution
7. customAfter the disappearance of bubbling
8. additionthe dropwise addition of an aqueous sodium nitrite solution
9. custombubbling
10. additionThe operation of re-starting the dropwise addition of sodium nitrite after the disappearance
11. customof bubbling
12. waitwas repeated and after 5 hours and 20 minutes
13. additionthe dropwise addition
14. customThe reaction solution obtained
15. extractionwas extracted with 10.0 g of methyl ethyl ketone
16. washthe organic: phase was washed with 5.0 g of an aqueous 5 mass % sulfuric acid solution
17. customthe methyl ethyl ketone was removed by distillation, as a result