The synthetic routes leading to 7-beta-hydroxyethyl- (I) and 7-beta-hydroxypropyl-8-benzylaminotheophylline (II) were described. Particularly the opening of oxazolidine ring in easy available oxazolidine-(2,3-f)-theophyllines with benzylamine was investigated. The structure of I, II and acetyl derivatives Ia, Ib, IIa and IIb was also confirmed by UV spectra.