Synthesis of linear and angular tricyclic guanidine derivatives, imidazo- or pyrimido-[2, 1-b]- or [1, 2-a] quinazoline derivatives, is described. Cyclization of 2-(ω-chloroalkyl)-4-phenyl-3, 4-dihydroquinazolines (9) gave two isomers and their isolation was troublesome. 2-Aminobenzhydrylaminoalkanols (10) obtained from 2-aminobenzophenone (5) were converted to linear tricyclic guanidine derivatives (3, 12, 13, 14, 15), and other tricyclic compounds (22 and 24) containing an oxygen or a sulfur atom. Reaction of 2-benzoylaminoalkanols (26) obtaired from (5) also gave angular products. Most of the tricyclic guanidine derivatives showed a hypoglycemic activity.