4-Vinyl-1,3-dioxolan-2-one (VEC) is a cyclic carbonate, that can be synthesized from acrolein by reacting with sulfur ylide and CO2. The ruthenium-catalyzed transfer hydrogenation (TH) of VEC in the presence of 2-propanol forms 1,2-butanediol. Indolines and indoles undergo selective C-H allylation with VEC in the presence of rhodium(III) catalyst.
In a 500 mL four-necked flask, 101.2 g of vinyl monochlorocarbonate, 0.60 g of polymerization inhibitor, 158.3 g of dimethyl carbonate were added, the temperature was raised to 55C, 104.4 g of triethylamine was added dropwise with stirring, and the temperature of the dropwise process was controlled to be 55-65C. The reaction solution was gradually blackened during the reaction. The reaction solution gradually turned black during the reaction. The reaction process was protected by nitrogen. Reaction 15 ~ 16 h, the end of the reaction, while hot filtration, with 158.3 g of dimethyl carbonate to wash the slag three times, add 0.5 g of polymerization inhibitor. Distill at atmospheric pressure at a temperature of not more than 95 , remove the remaining triethylamine and dimethyl carbonate. The product was distilled by rotary evaporator (vacuum 0.003 MPa) at a temperature of not more than 80 , and 34.76 g of vinylidene carbonate was obtained with a yield of 65%. The content of vinylidene carbonate was analyzed by gas chromatography 98.5%.
