反应详情

温度

95 °C

Process step c): 778.1 g (5.25 mol) of triethyl orthoformate were charged in a stirred vessel, the pressure within the vessel was slowly reduced to 170 mbar and the triethyl orthoformate was heated to 92° C. 134.3 g (0.35 mol-100% conversion in process steps a) and b) assumed) of ethyl 4,4-difluoroacetoacetate (in the form of a suspension coming from process step b)) were added at 92° C. to 95° C. within 4 hours. Thereafter, the reaction mixture was stirred at 95° C. for further 30 minutes. During the entire reaction time low boiling compounds were continuously removed by distillation under reduced pressure. Afterwards, the triethyl orthoformate was distilled by lowering the pressure accordingly. The resulting concentrated product suspension was cooled down to room temperature and 70.2 g of xylenes were added. The resulting suspension (178 g) comprised 40.0% (w/w) of the desired product (GC analysis, quantification with internal standard). This corresponds to an overall yield over the two synthetic steps of 91.6%, based on ethyl difluoroacetate used.

1. additionwere added at 92° C. to 95° C. within 4 hours
2. customDuring the entire reaction time low boiling compounds were continuously removed by distillation under reduced pressure
3. distillationAfterwards, the triethyl orthoformate was distilled
4. temperatureThe resulting concentrated product suspension was cooled down to room temperature
5. addition70.2 g of xylenes were added
6. customThis corresponds to an overall yield over the two synthetic steps of 91.6%