108160-11-8

6-Allyloxypurines readily undergo palladium-catalysed Claisen rearrangement under mild conditions affording N 1-substituted hypoxanthines. In contrast with the previously reported protocol, the Claisen rearrangement can be performed using Pd(PP

6-Allyloxy-9-benzylpurine (2) and 9-benzyl-6-propargyloxy purine (5) undergo normal thermal O->N rearrangement, either neat or in o-dichlorobenzene.The latter leads to the novel, 1-allenyl-9-benzyl-hypoxanthine (6).The related 4-allyloxy and 4-propargyloxy quinazolines (9, 12) also undergo smooth thermal O->N Claisen rearrangement.In the case of (12), the primary allenic product is further transformed into 3-propargylquinazolin-4-one (13) and the allene dimer (14).