3H-2,1-Benzoxaborole-1-spiro-4'-(5-oxa-3a-aza-4-borapyrene).

In the title compound, C(20)H(14)BNO(2), the B atom has a tetra-hedral geometry with two short B-O and two long B-C and B-N bonds, revealing a significant difference between C(ar)-O-B and C(alk-yl)-O-B bond distances. Inter-molecular Ar-H⋯O hydrogen bonds and strong π-π inter-actions (3.368 Å) between aromatic cores of neighbouring mol-ecules result in hexa-gonal channels along the crystallographic c axis, which are potentially accessible for small mol-ecules.