Crystal structure of an unexpected adduct of triphenylphosphine oxide to 1-(2'-hydroxy-3',6'-diethylphenyl)-2-(bromomethyl)naphthalene

The title adduct is a by-product of the synthesis of benzonaphthopyrans. It crystallizes from dichloromethane/petroleum ether monoclinically in the space group P2 1 /n with a = 1695.8(4), b = 2133.7(6), c = 935.3(2) pm, and β = 101.03(2)°