Synthesis of Kinetin-Analogues IV

In previous paper of this series it was reported that the kinetin-analogues which have an aromatic or heterocyclic ring instead of furane ring have almost the same activity as kinetin on leaf growth. In this paper a study was made to ascertain by what kinds of ring the furane ring might be replaced and the same activity as kinetin be still retained. Another study also was made to investigate the effect of carbon numbers between purine nucleus and attached benzene ring on the leaf-growth promoting activity of phenyl alkylamino-purine. The kinetin-analogues having 0, 1 and 2 carbon atoms have almost the same activity as kinetin. In the case of n=4 or 5 it has almost inactive. The analogues, having naphthalene, biphenyl, phenanthrene or anthracene ring, have lower activity than kinetin