Several pseudohalide containing ionic liquids with quarternary ammonium counter cations of the general formula [R3MeN]X [R = ethyl (1X), n‐butyl (2X) with X– = CN–, N3–, OCN–, and SCN–] were synthesized by decomposition of the corresponding trialkylammonium methylcarbonate in the reaction with Me3Si–X. We also treated 2CN with OP(OMe)3, yielding [nBu3MeN][O2P(OMe)2] and acetonitrile (Me‐CN). The double salt [nBu3MeN]2{[B(OMe)3(CN)](CN)} was obtained from the reaction of 2CN with B(OMe)3, featuring the formation of the monocyanotrimethoxyborate anion, [B(OMe)3(CN)]–, co‐crystallized with [nBu3MeN]CN. [nBu3MeN]2{[B(OMe)3(CN)](CN)} was fully characterized including structure elucidation.