S.M. Kaiser and R. J. Quinn, “Adenosine Receptors as Potential Therapeutic Targets,” Drug Discovery Today, Vol. 4, No. 12, 1999, pp. 542-551.
http://dx.doi.org/10.1016/S1359-6446(99)01421-X

has been cited by the following article:

• TITLE: Synthesis of C-8 alkyl xanthines by pentaamminecobalt(III) complex

  AUTHORS: Renuka Suravajhala

  KEYWORDS: Alkyl Hydrazine; Radical Alkylation; Caffeine; Homolytic Aromatic Substitution; Pentaamminecobalt(III)

  JOURNAL NAME: Advances in Biological Chemistry, Vol.3 No.6, December 12, 2013

  ABSTRACT: Alkyl xanthines underwent selective homolytic aromatic substitution at C-8 position with alkyl groups of pentaamminecobalt(III) complex. In this process of synthesis, we used monoalkyl hydrazines as the radical source in aqueous ammonia solution. Evidence supporting coordination of the alkyl hydrazine to pentaamminecobalt(III) complex by radical trapping was in good agreement with literature. The products were characterized using GC-MS and 1H, 14N and 59Co NMR spectroscopy.