1-Benzyl-3-methyl-3',5'-diphenyl­spiro­[quinoxaline-2(1H),2'(3'H)-1,3,4-thia­diazole]

In the title spiro compound, C₂₉H₂₄N₄S, the quinoxaline and thia­diazole ring systems share a common C atom; their mean planes are aligned at 87.0 (1)° in one mol­ecule and at 84.1 (1)° in the other independent mol­ecule. The thia­zole ring possesses two aromatic ring substituents and is roughly coplanar with these rings [the dihedral angles between the thia­diazole and phenyl rings are 10.7 (1) and 11.7 (1)° in one mol­ecule, and 16.8 (1) and 17.7 (1)° in the other]. The aromatic ring of the benzyl unit of one mol­ecule is disordered over two orientations in a 1:1 ratio.

Ethyl 2-(2-amino-5-methyl-1,2,4-triazolo[1,5-a]pyrimidin-7-yl)acetate

The nine-membered fused-ring of the title compound, C₁₀H₁₃N₅O₂, is approximately planar [maximum deviation = 0.012 (1) Å]; the bond angle at the methylene C atom is 111.33 (10)°. In the crystal, the amino group forms hydrogen bonds to the N atoms of the triazole rings of adjacent mol­ecules, generating a ribbon running along the a axis.