SR-4895

合成路线:The reaction of phenylhydrazine (I) with propionaldehyde (II) gives the corresponding hydrazone (III),which is condensed with phenyldiazoninum chloride (IV) to yield the formazan (V).The cyclization of (V) by means of BF3 in hot acetic acid affords 3-ethyl-1,2,4-benzotriazine (VI),which is finally oxidized to the target dioxide by means of H2O2 and trifluoroacetic anhydride in dichloromethane.

参考文献标题:1,2,4-Benzotriazine 1,4-dioxides.An important class of hypoxic cytotoxins with antitumor activity
文献作者:Kelson,A.B.; et al.
参考来源:Anti-Cancer Drug Des 1998,13(6),575


合成路线:The reaction of 2-nitroaniline (I) with cyanamide and HCl at 100 C,followed by a treatment with NaOH at the same temperature gives the benzotriazine N-oxide (II),which is diazotized with NaNO2 and HCl,followed by a treatment with POCl3 and dimethylaniline to yield the chloro derivative (III).The reaction of (III) with tetraethyltin and Pd(PPh3)4 in hot DME affords the ethyl derivative (IV),which is finally oxidized with trifluoroperacetic acid in dichloromethane to provide the target N1,N4-bis oxide compound.
参考文献标题:New and versatile syntheses of 3-alkyl- and 3-aryl-1,2,4-benzotriazine 1,4-dioxides: Preparation of the bioreductive cytotoxins SR 4895 and SR 4941
文献作者:Hay,M.P.; Denny,W.A.
参考来源:Tetrahedron Lett 2002,43(52),9569