2-Amino-3-hydrazinoisocarbostyril誘導体のs-Triazolo[1,5-b]isoquinolin-5(1H)-oneおよび1,2-Dihydro-6H-s-tetrazino[2,3-b]isoquinolin-6-oneへの閉環反応

抄録

Cyclization of 2-amino-3-hydrazinoisocarbostyril (I) and its derivatives (IIa-d and IIIa-f) was studied. The reaction of I with N, N-dimethylformamide dimethyl acetal gave 1-(N, N-dimethylaminomethyleneamino)-s-triazolo[1, 5-b]isoquinolin-5(1H)-one (IVa), and with formamidine acetate, 1-aminotriazoloisoquinolinone (IVb), which was produced by the reaction of IIc with N, N-dimethylformamide diethyl acetal. The reaction of IIa with the same reagent afforded 1-benzylideneamino derivative (IVd), but no cyclization products were obtained from IIb and IId, and their reactions resulted in 2-(N, N-dimethylaminomethyleneamino)isocarbostyrils (Vb and Vd). 1, 2-Dihydro-6H-s-tetrazino[2, 3-b]isoquinolin-6-ones (VIa-e) were produced by the cyclization of IIIa to IIIe with N, N-dimethylformamide diethyl acetal. VIa and VIb can also be obtained by the reaction of I with acetic anhydride or propionic anhydride in ethyl orthoformate. 1-Methyl-2-acyltetrazinoisoquinolinone derivatives (VIIIa, VIIIb, VIIId, and VIIIe), which were prepared by the methylation of VIa to VIe with dimethyl sulfate or methyl iodide, were converted into 1-methylaminotriazoloisoquinolinones (IXa-c) under alkaline conditions, as a result or deacylation ana ring contraction.