A series of 9-benzyl-6-(dimethylamino)-9H-purines and 9-benzyl-2-chloro-6- (dimethylamino)-9H-purines were synthesized and tested in cell culture for activity against rhinovirus type 1B. The 9-benzylpurines that were unsubstituted in the 2-position had weak activity. However, introduction of a 2-chloro substituent resulted in a substantial increase in antiviral activity. One of the most active compounds, 2-chloro-6-(dimethylamino)-9-(4- ...