Temozolomide hydrochloride dihydrate

Abstract

The X-ray crystal structure of temozolomide hydrochloride shows that the dihydrate salt contains one neutral temozolomide, one temozolomide-H +Cl-, one H3O+·Cl -, and three water molecules. This is the first crystallographic evidence of a protonated form of the antitumour drug temozolomide. The protonation of water O and imidazole N of the drug are rationalized by calculated pKas. © 2013 The Royal Society of Chemistry.