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

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O3—H3⋯O4i	0.84	1.83	2.669 (3)	173
N2—H2⋯O4ii	0.88	2.28	3.091 (3)	154
O4—H4A⋯O1iii	0.96 (3)	1.79 (3)	2.737 (2)	170 (3)
O4—H4B⋯O2iv	0.81 (3)	2.08 (4)	2.863 (3)	164 (3)

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) .