c11h11n

from The Collaborative International Dictionary of English v.0.48

Cryptidine \Cryp"ti*dine\ (kr?p"t?-d?n; 104), n. [Gr. krypto`s
   hidden.] (Chem.)
   One of the quinoline bases, obtained from coal tar as an oily
   liquid, {C11H11N}; also, any one of several substances
   metameric with, and resembling, cryptidine proper.
   [1913 Webster]