The initial detection of methyl cyanide (CH3CN) was reported by
Solomon et al. in 1971 in
B. They used the
radio telescope to make their observations. The first extragalactic detection was noted by
Mauersberger et al. in 1991.
Methyl cyanide was also observed in
Comet Kohoutek by
Ulich and Conklin.
UPDATE (July 2018): Methyl cyanide was detected in the protoplanetary disk
MWC 480 by
Öberg et al. in 2015.
Methyl cyanide or
acetonitrile is poisonous, but it is not as toxic as HCN.