Reaction of 7-(2-Mesyloxy-2-phenylethyl)theophylline with Amines: Synthesis of 1,2,3,6-Tetrahydro-6-imino-2-oxo-7H-purine Derivatives

Theophylline was converted to 7-(2-phenyl-2-methanesulfonyloxy)ethyl congener and the product was treated with ammonia or primary amines in a mixture solution of water and organic solvents. Two products were proven to be the styrene analogue and 7-(2-amino-2-phenylethyl)theophylline. The structure of the third product was elucidated as the 1,2,3,6-tetrahydro-6-imino-2-oxo-7H-purine derivatives by spectroscopic analysis including HMBC correlation and X-ray crystallography.