91099-20-6Relevant academic research and scientific papers
Camptothecin derivatives
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, (2008/06/13)
New campotothecin derivatives and a process for preparing same are disclosed, which are represented by the general formula: STR1 wherein R1 represents a lower alkyl group, R2 represents a hydrogen atom or an amino, hydroxyl, lower acylamino or lower alkoxy group, R3 represents a hydrogen or halogen atom or a lower alkyl, hydroxyl, lower alkoxy, nitro, amino, cyano or di(lower alkyl)amino group, R4 represents a hydrogen or halogen atom or a lower alkyl, hydroxyl, lower alkoxy, lower alkylthio, amino, cyano or di(lower alkyl)amino group, and R5 represents a hydrogen or halogen atom or a hydroxyl or lower alkoxy group, with the proviso that all of the R2, R3, R4 and R5 substituents should not be a hydrogen atom and also that if any one of the R2, R3, R4 and R5 is a hydroxyl or lower alkoxy group, all of the other three substituents should not be a hydrogen atom.
Central Nervous System Active Compounds. XIV On the Cyclization of N-Acyl-N'-arylureas
Heinicke, Grant,Hung, Tran V.,Prager, Rolf H.,Ward, A. David
, p. 831 - 844 (2007/10/02)
The cyclization of N-acyl-N'-arylureas in polyphosphoric acid has been reinvestigated.The product is not only the 4-substituted quinazolin-2(1H)-one as reported, but also contains the 2-acylaniline in major proportions.Two minor products have also been isolated.At 80 deg, an intermediate has been detected, the properties of which are consistent with it being the corresponding 2-acylphenylurea.Acyl ureas with strongly electron-withdrawing acyl groups from major amount of the corresponding anilide by the formal loss of cyanic acid.The application of this reaction tothe synthesis of quinazolinylphthalides has been investigated.
