The invention discloses a synthesis method of 3,3,4,4-tetrafluoropyrrolidine and mainly solves the technical problems of poisonous introduced
fluorine, relatively long steps and relatively low yield in the existing synthesis process. The synthesis method disclosed by the invention comprises four steps: firstly, mixing butanedione with
chloroform, then, carrying out addition on the mixture and
bromine to form 1,4-dibromo-2,3-butanedione; secondly, introducing
sulfur tetrafluoride into the obtained 1,4-dibromo-2,3-butanedione, and carrying out a reaction to obtain 1,4-dibromo-2,2,3,3-tetrafluorobutane; thirdly, carrying out a high-temperature reaction on 1,4-dibromo-2,2,3,3-tetrafluorobutane and
benzylamine to obtain 1-benzyl-3,3,4,4-tetrafluoropyrrolidine
hydrochloride; and fourthly, carrying out
catalytic hydrogenation debenzylation on 1-benzyl-3,3,4,4-tetrafluoropyrrolidine
hydrochloride to obtain 3,3,4,4-tetrafluoropyrrolidine. The invention provides the synthesis method of 3,3,4,4-tetrafluoropyrrolidine which is relatively low in
toxicity, low in
raw material price, simple in operation and high in yield.