2,9,10-Trimeth­oxy­dibenzo[b,d]oxepin-7(6H)-one

The title compound, C₁₇H₁₆O₅, was prepared through a cyclization reaction of 2-(3',4',5-trimeth­oxy­biphenyl-2-yl­oxy)acetyl chloride. The two benzene rings form a dihedral angle of 34.55 (5)°. The crystal structure does not feature any hydrogen bonds.