2,2-Difluoro-1,3-benzodioxole

Colorless to pale yellow liquid

Weigh 100g Benzodioxole, 900g acetonitrile, mix and prepare Benzodioxole acetonitrile solution with a mass fraction of 10percent, again add 1g of trifluoroacetic acid and mix for use. The flow rate of fluorine gas and nitrogen gas is adjusted to prepare a fluorine gas nitrogen mixed gas with a mass fraction of 10percent, which is ready for use. Using the reaction process shown in Figure 1, a microchannel reactor made of silicon carbide is used.The liquid holding capacity of each module is 1ml, and the reaction temperature of the module is set to -20 °C.Control the pumping rate to adjust the reaction residence time, Set the dwell time to 20s, The A module was continuously pumped in a 10percent mass fraction of Benzodioxole acetonitrile solution (containing 1percent trifluoroacetic acid) for pre-cooling.At the same time, the B module continuously and uniformly passes a fluorine gas mixed gas with a mass fraction of 10percent.The molar amount of fluorine gas is 2.2 times that of the Benzodioxole, and the reaction is mixed in the CDEF module.Enter the gas-liquid separator, the gas is treated and discharged, and the liquid is collected.The liquid was subjected to water washing and distillation to obtain a product of 1, 3-benzodioxole-2, 2-difluoro in a yield of 90percent and a content of 99percent.24 ml (0.2 mol) of a pepper ring was added to a 250 ml lined PTFE stainless steel flask, Phosphonium chloride 97.6g and phosphorus pentachloride 83.3g (0.4m0l), the temperature rose to reflux reaction, GC detection of raw material pepper ring content of less than 0.2percent reaction end; the reaction solution distillation distillation distillation of by-product three Phosphorus chloride and solvent phosphorus oxychloride, vacuum distillation temperature of 110 ° C, vacuum degree of -0.095MPa; vacuum distillation after the end of cooling to 4 ° C, in the vacuum of -0.095MPa drop Plus hydrogen fluoride liquid 8g (0.4mol), dropping finished, incubated for 2 hours, and then release the by-product of hydrogen chloride, and then add saturated sodium carbonate solution, adjust the solution PH value of 6.5 ~ 7.5, stirring 0.5 hours, , The organic layer was distilled after the colorless transparent liquid for the finished 2, 2 - difluoro - 1, 3 - benzodiazepine 28.8g, yield 99.8percent, GC purity 99.8percent(1) In a 1000 mL autoclave, 55.0 g (0.5 mol) of catechol, Potassium carbonate 85.0 g (0.62 mol), NMP (N-methylpyrrolidone) 200ml, 0.5 g of tetrabutylammonium iodide and 157 g (0.75 mol) of dibromodifluoromethane were added to the reaction vessel.Warming up to 100 ° C, Reaction 8h, After cooling to room temperature, pour the reaction solution into 500 ml of crushed ice.Stir until the ice is completely dissolved, Let stand for liquid separation, Remove the water phase, The organic phase was dried by adding 10 g of anhydrous sodium sulfate.Obtaining crude 2, 2-difluorobenzo-1, 3 dioxolane, Re-distillation, Obtaining a fine 2, 2-difluorobenzo-1, 3 dioxol 63g (0.4 mol);

Molecular Weight:158.10
XLogP3:2.5
Hydrogen Bond Acceptor Count:4
Exact Mass:158.01793569
Monoisotopic Mass:158.01793569
Topological Polar Surface Area:18.5
Heavy Atom Count:11
Complexity:145
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes