Ambroxol Theophylline-7-acetate Salt Monohydrate

In the title monohydrate salt of ambroxol (AMB) with theophylline-7-acetic acid (TAA), C₁₃H₁₉Br₂N₂O⁺.C₉H₉N₄O₄⁻.H₂O, protonation of the secondary amino group of AMB takes place. An N⁺—H...O⁻ hydrogen bond is established between the protonated N atom and an O atom of the carboxylate anion, the same atom as is involved in an N—H...O interaction with the aromatic amino group of the cation. The other O atom of the carboxylate anion participates in an N⁺—H...O⁻ hydrogen bond with a symmetry-related salt molecule, giving rise to a dimeric arrangement. The water molecule is linked to a carbonyl O atom of TAA and the aromatic amino group of AMB, and connects the salt molecules in the crystal at the level of the OH group of AMB.

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