Design of a series of cocrystals featuring isoniazid modified with diacetone alcohol

Eight cocrystals containing an isoniazid derivative derivatized with diacetone alcohol [N′-[(2E)-4-hy­droxy-4-methyl­pentan-2-yl­idene]pyridine-4-carbohydrazide, iz4h4m2p] were synthesized and characterized. All coformers used in this work feature at least one carb­oxy­lic acid functional group. These coformers include: succinic acid, 3,5-di­nitro­benzoic acid, 4-nitro­benzoic acid, 2-chloro-4-nitro­benzoic acid, 2,5-di­hydroxy­benzoic acid, 3-hy­droxy­benzoic acid, 4-hy­droxy­benzoic acid and cinammic acid. Crystal structures were obtained using single crystal X-ray diffraction, which shows that cocrystals containing iz4h4m2p feature a similar chain hydrogen bond between molecules of iz4h4m2p in addition to the expected carb­oxy­lic acid⋯pyridine hydrogen-bond interaction. Differences between the structures arise when additional hydroxyl group(s) are present, such as the case featuring the hy­droxybenzoic acids. These structures are compared to their isoniazid counterparts presented previously in the literature. All cocrystals were also characterized with differential scanning calorimetry and Fourier transform infrared spectroscopy.