Mono-α-carbamoylethylthio-Substituted Pyrazolo[3,4-d]pyrimidines: the Position of Substitution

Abstract

Pyrazolo [3,4-d] pyrimidines are a general class of compounds which exhibit adenosine receptor affinity. One particular compound, α-{6-(1α-carbamoylethylthio)-1-phenylpyrazolo-[3,4-d]pyrimidin-4-ylthio} propionamide (1a), has been shown to have antagonist activity an order of magnitude greater than theophylline at the A1 adenosine receptor. The synthesis, structural elucidation by n.m.r. spectroscopy, and adenosine receptor affinity of the mono-α- carbamoylethylthio analogue is now reported.