1-Carb­oxy­naphthalen-2-yl acetate monohydrate

In the title compound, C₁₃H₁₀O₄·H₂O, both the carboxylic acid [C_ar-C_ar-C-O = -121.1 (2)°, where ar = aromatic] and the ester [C_ar-C_ar-O-C = -104.4 (3)°] groups lie out of the mean plane of the conjugated aromatic system. In the crystal, the organic mol­ecule is hydrogen bonded to water mol­ecules through the ester and carb­oxy moieties, forming chains along the a-axis direction. The methyl H atoms of the acet­oxy group are disordered over two equally occupied sites.

2-(5-Methyl-1,3,4-oxa­diazol-2-yl)phenyl acetate

In the title compound, C₁₁H₁₀N₂O₃, which is a potential bioactive compound, the benzene and oxa­diazole rings are approximately coplanar, with an inter-ring dihedral angle of 4.14 (2)°, while the ester plane is rotated out of the benzene plane [dihedral angle = 82.69 (9)°]. In the crystal, the mol­ecules form layers down the a axis with weak π–π inter­actions between the oxa­diazole and benzene rings [minimum ring centroid separation = 3.7706 (14) Å].