9H-Purin-2-amine, 6-[[(3-bromophenyl)methyl]thio]-9-.beta.-D-ribofuranosyl- 9H-Purine, 2-amino-6-(m-bromobenzylthio)-9-.beta.-D-ribofuranosyl- 9H-Purine, 2-amino-6-[(m-bromobenzyl)thio]-9-.beta.-D-ribofuranosyl- NSC54264 PC 43