| 摘要 |
2-(difluoromethoxy)-1,2,2,2-tetrafluoroethane (CHF2OCHFCF3), a known inhalation anaesthetic, is prepared by a synthetic route in which a first and novel intermediate: p-CH3C6H4CHF2OCHFCF3 is prepared by reacting methyl hemiacetal (CF3CH(OH)OCH3) with para-toluene sulphonyl chloride in the presence of an organic base such as triethylamine at room temperature. The resulting novel tosylate intermediate is then converted to a second intermediate CF3CHFOCH3 by reaction at elevated temperature with a fluorinating agent such as caesium fluoride. The second intermediate is converted by known means to CHF2OCHFCF3 (eg by photochemical chlorination) followed by fluorination of the resulting compound with HF in the presence of SbCl5. |
