Caffeine–N-phthaloyl-β-alanine (1/1)

The title co-crystal [systematic name: 3-(1,3-dioxoisoindolin-2-yl)propanoic acid–1,3,7-trimethyl-1H-purine-2,6(3H,7H)-dione (1/1)], C₈H₁₀N₄O₂·C₁₁H₉NO₄, is the combination of 1:1 adduct of N-phthaloyl-β-alanine with caffeine. The phthalimide and purine rings in the N-phthaloyl-β-alanine and caffeine mol­ecules are essentially planar, with r.m.s. deviations of the fitted atoms of 0.0078 and 0.0118 Å, respectively. In the crystal, the two mol­ecules are linked via an O—H...N hydrogen bond involving the intact carb­oxy­lic acid (COOH) group. The crystal structure is consolidated by C—H...O inter­actions. The H atoms of a methyl group of the caffeine mol­ecule are disordered over two sets of sites of equal occupancy.