2-Chloro-5-cyanopyrazine , its cas register number is 36070-75-4. It also can be called 5-Chloropyrazine-2-carbonitrile ; 5-Chloro-2-pyrazinecarbonitrile ; 2-pyrazinecarbonitrile, 5-chloro- ; 5-chloropyrazine-2-carbonitrile .