Dabco → HCID 15252136, compound

Participants

Reaction Conditions

Reaction Steps

Ethyl triflate (3.56 g, 20.0 mmol) was added dropwise to a cold (0° C.) stirred solution of 1,4-diazabicyclo[2,2,2]octane (3.26 g, 29.1 mmol) in dry acetonitrile (25 cm3) under dry nitrogen. The reaction mixture was stirred at 0° C. for 1 hour and then at 20° C. for 3 hours; no precipitate appeared. The solution was rotary evaporated at water-pump pressure, and the white solid residue remaining was washed with cold diethyl ether to remove unreacted 1,4-diazabicyclo-[2,2,2]octane and then dried in vacuo, to give 1-ethyl-4-aza-1-azoniabicyclo[2,2,2]octane triflate (5.30 g, 18.3 mmol, 91.5%) shown by 1H n.m.r. analysis to contain a trace of 1,4-diethyl-1,4-diazoniabicyclo[2,2,2]octane ditriflate. A pure sample of the monoquaternary salt, m.p. 117°-119° C., δH (D2O soln.) 1.32 (tt; N+CH2CH), 3.18 (m; 3×ring CH2), 3.25-3.4 (complex, two overlapping absorption systems; 3×ring CH2 +N+CH2CH3), p.p.m., δF (same soln.; ext. CF3CO2H ref.) 0.03 (s; CF3SO3-) p.p.m., was obtained by recrystallizing the slightly impure product from an ethanol-diethyl ether mixture.

Provenance & Evidence