名称:
                                Guanidine-Annelated Heterocycles XVI. A Practical Synthesis of 7-Chloro-4-phenylamino[1,2,4]triazoloquinazolin-5(4H)-ones
                             
                            
                                摘要:
                                The triazolo[2,3-a]quinazolin-5(4H-ones 9a-c can be prepared via Dimroth rearrangement by treatment of 5 with representative carboxylic acid orthoesters 6a-c each heating at 40 degrees C more elevated temperature than the preparation of their analogous triazolo[4,3-a] isomers 7a-c.