New purine derivatives with useful plant-growth regulating properties

The corresponding 6-substituted amino-9-aryl-9H-purines 4a-k are synthesized from reactions of 6-chloro-9-[p-anisyl]-or 9-[p- chlorophenyl]-9H-purines 3c and d with primary amines. Products 4d and k are also obtained by fusing 6-methylthiopurines 5 a and b with benzyl and p-anisyl amines. Most of the products 4a-k have been screened for activity as plant-growth regulating factors for wheat plant. Ring closure of 5-acetylamino 1-arylimidazole-4-carboxamides 6 by methanolic sodium hydroxide solution afforded the corresponding 9-aryl 2-methyl-hypoxantlines 7. The action of phosphoryl chloride on the latter products gave their 6-chloro derivatives 8. Treatment of 8b with p-toludine yielded its 9-[p-anisyl]-2-methyl-6-[p-tolylamino] purine 4 I