Organomercury Medicinal Chemistry. Synthesis and Structure of a (beta-Methoxyethyl)mercury(II) Derivative of N(7)-Deprotonated Theophylline, [Hg(C3H7O)(C7H7N402)]

Organomercury compounds are widely used in medicinal applications. Alkoxyalkylmercurials have been used as fungicides and bacteriocides and, in addition, a range of diuretics containing substituted (betap-methoxyethyl)mercury(II) groups RCH(OMe)CH2Hg and CH2(OMe)CH(R)Hg, have been extensively used since the 1920's. Theophylline is often administered in conjunction with the mercurial diuretics as its presence greatly enhances diuretic effectiveness, but the nature of any chemical reaction between organomercurials and theophylline has not been established. We report here the isolation of a crystalline complex from the reaction of (beta-methoxyethyl)mercury(II) acetate and theophylline, and a crystallographic determination of the binding site for mercury in the complex. The complex may be regarded as a model for the species formed on co-administration of an organomercury diuretic with theophylline. The structure consists of molecules of [Hg(CH2CH2OCH3)(C7H7N402)] linked into a three-dimensional network by weak intermolecular Hg..O (methoxyethyl) and Hg..N(9) (theophylline) interactions of 2,89(1) and 2,91(1) A respectively. The mercury atom is bound to the deprotonated nitrogen atom N(7), with Hg-N(7) 2,08(1), Hg-C (methoxyethyl) 2,13(2) A and C-Hg-N(7) 173.3(6)°.