The two aromatic systems in the title compound, C(11)H(11)N(3), are inclined by 19.1 (1)°, whilst the angle at the central amino N atom is 130.3 (2)°. The amino group forms a hydrogen bond to the pyrazine N-4 atom of an adjacent mol-ecule, forming a chain motif.
There are two mol-ecules in the asymmetric unit of the title compound, C(11)H(9)ClN(2), with dihedral angles of 41.84 (12) and 49.24 (12)° between the aromatic ring planes. The two mol-ecules form a dimer via a pair of N-H⋯N hydrogen bonds.
There are two mol-ecules in the asymmetric unit of the title compound, C(14)H(10)ClN(3), with dihedral angles of 5.11 (10) and 13.61 (10)° between the aromatic ring systems. In the crystal structure, mol-ecules are linked by N-H⋯N hydrogen bonds, resulting in chains propagating in [010].
The two aromatic rings in the title compound, C(10)H(9)N(3), are inclined at 15.2 (1)° to each other; this opens up the angle at the amino N atom to 130.4 (1)°. The amino N atom forms a hydrogen bond to the 4-N atom of an adjacent mol-ecule to create a chain motif.
In the title compound, C(10)H(8)ClN(3), the dihedral angle between the aromatic rings is 43.0 (1)° and the bridging C-N-C angle is 128.19 (16)°. The amino N atom of one mol-ecule forms a hydrogen bond to the 1-N atom of an adjacent pyrazinyl ring, generating an inversion dimer.
The aromatic and the aromatic fused-rings in the title compound, C(15)H(13)N(3), open the angle at the planar N atom to 130.07 (13) and 129.98 (13)° in the two independent mol-ecules in the asymmetric unit. The amino N atom of one mol-ecule forms a hydrogen bond to the 4-N atom of an adjacent quinoxalinyl ring, generating a supra-molecular chain.