Synthetic Approaches to 5:8-Fused Heterocyclic Systems. A Novel Rearrangement During the Synthesis of Imidazo[4,5-e][1,2,4]triazocine Ring System
摘要:
The attempted ring-closure of 4-amino-1-benzyl-5-[(N-2-benzyl-N-2-methoxycarbonyl)hydrazinomethylenecarbonyl]imidazole (5b) in sodium hydride/dimethyl sulfoxide at 50-60 degrees C afforded 1, 7-dibenzylxanthine (6) instead of the anticipated 5:8-fused heterocycle 4b. A tentative reaction pathway has been proposed for the observed transformation.
Synthetic Approaches to 5:8-Fused Heterocyclic Systems. A Novel Rearrangement During the Synthesis of Imidazo[4,5-e][1,2,4]triazocine Ring System
摘要:
The attempted ring-closure of 4-amino-1-benzyl-5-[(N-2-benzyl-N-2-methoxycarbonyl)hydrazinomethylenecarbonyl]imidazole (5b) in sodium hydride/dimethyl sulfoxide at 50-60 degrees C afforded 1, 7-dibenzylxanthine (6) instead of the anticipated 5:8-fused heterocycle 4b. A tentative reaction pathway has been proposed for the observed transformation.