In the mol-ecules of the title compounds, methyl 5-bromo-2-[(2-chloro-quinolin-3-yl)meth-oxy]benzoate, C18H13BrClNO3, (I), methyl 5-bromo-2-[(2-chloro-6-methyl-quinolin-3-yl)meth-oxy]benzoate, C19H15BrClNO3, (II), methyl 2-[(2-chloro-6-methyl-quinolin-3-yl)meth-oxy]benzoate, C19H16ClNO3, (III), which crystallizes with Z' = 4 in space group P212121, and 2-chloro-3-[(naphthalen-1-yl-oxy)meth-yl]quinoline, C20H14ClNO, (IV), the non-H atoms are nearly coplanar, but in {5-[(2-chloro-quinolin-3-yl)meth-oxy]-4-(hy-droxy-meth-yl)-6-methyl-pyridin-3-yl}methanol, C18H17ClN2O3, (V), the planes of the quinoline unit and of the unfused pyridine ring are almost parallel, although not coplanar. The mol-ecules of (I) are linked by two independent π-π stacking inter-actions to form chains, but there are no hydrogen bonds present in the structure. In (II), the mol-ecules are weakly linked into chains by a single type of π-π stacking inter-action. In (III), three of the four independent mol-ecules are linked by π-π stacking inter-actions but the other mol-ecule does not participate in such inter-actions. Weak C-H⋯O hydrogen bonds link the mol-ecules into three types of chains, two of which contain just one type of independent mol-ecule while the third type of chain contains two types of mol-ecule. The mol-ecules of (IV) are linked into chains by a C-H⋯π(arene) hydrogen bond, but π-π stacking inter-actions are absent. In (V), there is an intra-molecular O-H⋯O hydrogen bond, and mol-ecules are linked into sheets by a combination of O-H⋯N hydrogen bonds and π-π stacking inter-actions.
Keywords: 2-chloroquinolines; crystal structure; hydrogen bonding; molecular conformation; π–π stacking interactions.