N-t-Butyliminoacetonitrile (2) constitutes the first known member of a new family of compounds, the iminoacetonitriles RN =CHCN.IN the probable prebiotic chemical evolution of adenine by pentamerization of hydrogen cyanide, it is assumed that a dimer of the latter is a critical intermediate.l Although it remains undetected, iminoacetonitrile has been a suggested2 dimer of hydrogen ~y a n i d e . ~. ~We describe N-t-butyliminoacetonitrile ( 2 ) , the first known member of the family of N-substituted iminoacetonitriles.Following a general procedure,5 N-t-butylaminoacetonitrile ( l ) , b.p. 60.5-61.5"/7 mm,6 n% 1.4307,6 n.m.r. (CCI,) 8 3.49 p.p.ni.