Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3C⋯N2Ai	0.87	1.99	2.857 (3)	173
N1A—H1A⋯O3	0.88	2.03	2.849 (3)	154
N1B—H1B⋯O4	0.88	1.91	2.776 (4)	168
N2B—H2B⋯O4Aii	0.88	1.96	2.812 (4)	162

Symmetry codes: (i) ; (ii) .