Abstract
The title compound, C(4)H(4)N(2)S, was obtained by the reduction of 2-mercapto-pyrazine (during its crystallization with 2-mercapto-pyrazine and isonicotinic acid N-oxide in ethanol solution. It crystallizes in the monoclinic space group P2(1)/m. In the crystal, the mol-ecules are linked by N-H⋯N and C-H⋯S hydrogen bonds.