Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N5—H51⋯N6i	0.88 (2)	2.28 (2)	3.080 (3)	153 (2)
N6—H61⋯O1ii	0.86 (2)	2.34 (2)	3.120 (3)	152 (2)
N6—H62⋯N15ii	0.87 (3)	2.56 (3)	3.408 (3)	164 (2)

Symmetry codes: (i) ; (ii) .