Toluene → N,N,N',N'-tetramethylformamidinium para-toluenesulfonate

Participants

Reaction Conditions

Reaction Steps

A mixture of N-formylpyrrolidine (100 g) and dimethylsulfate (126 g) are heated to 80° C. for 4 h. Then a mixture of pyrrolidine (71 g) and toluene (100 ml) are added and the resulting mixture is stirred at reflux for 1 h. The reaction mixture is cooled to room temperature and the phases are separated. The lower layer is concentrated in vacuo and triturated with diethyl ester. The precipitate is collected by filtration and recrystallised using ethyl acetate to give 1-pyrrolidin-1-ylmethylene-pyrrolidinium methylsulfate (18, R6/R7=Pyrrolidinyl). 1H NMR (DMSO-d6), 8.28 (1H), 3.90-3.85 (4H), 3.68-3.62 (4H), 3.38 (3H), 1.99-1.90 (4H), 1.86-1.77 (4H).

Provenance & Evidence