59648-15-6Relevant academic research and scientific papers
The synthesis of 6,9-bis[(aminoalkyl)amino] substituted benzo[g]quinoxaline-, benzo[g]quinazoline- and benzo[g]phthalazine-5,10- diones via regiospecific displacements
Krapcho,Maresch,Helgason,Rosner,Hacker,Spinelli,Menta,Oliva
, p. 1597 - 1606 (2007/10/02)
The synthesis of 6,9-difluoro substituted benzo[g]quinoxaline-5,10-diones (3A), benzo[g]quinazoline-5,10-diones (3B) and benzo[g]phthalazine-5,10- diones (3C) have been accomplished. Treatment of 3A, 3B or 3C with diamines or N-(t-butoxycarbonyl)ethylenediamine led to the corresponding 6,9- bis[(aminoalkyl)amino]-substituted analogues related to 2A, 2B and 2C, respectively. The mono-substituted derivatives 4h and 4i could be isolated from displacements commencing from 3A. A competitive ring-opening of the pyrimidine ring of 2C occurred during the reaction with N,N- dimethylethylenediamine. Removal of the BOC-protecting group from 2Ac led to the hydrochloride salt 2Ab. A novel synthetic pathway to 6,9- dihydroxybenzo[g]phthalazine-5,10-dione (21a) was developed. Conversion of 21a to the ditosylate 21b was readily accomplished. Treatment of 21b with N,N-dimethylethylenediamine or N-(t-butoxycarbonyl)ethylenediamine led to 2Ca and 2Cc, respectively. Removal of the BOC-protecting group from 2Cc with trifluoroacetic acid followed by ion-exchange led to the hydrochloride salt 2Cb. Treatment of ditosylate 21b with N-(t-butoxycarbonyl)ethylenediamine also led to the mono-substituted analogue 25a along with a small amount of the O-S cleavage product 25b. Treatment of 25a with N,N- dimethylethylenediamine led to the unsymmetrically substituted derivative 25c which was converted into the trifluoroacetate salt 25d.
Ring-Chain Isomerism of Some 4,5-Disubstituted Pyridazines involving Heterospiro-compounds
Chimichi, Stefano,Nesi, Rodolfo,Scotton, Mirella,Mannucci, Carlo,Adembri, Giorgio
, p. 1339 - 1343 (2007/10/02)
I.r., u.v., and 1H n.m.r. spectral evidence demonstrated that 5-(o-aminophenylcarbamoyl)pyridazine-4-carboxylic acid (4), for which the zwitterionic structure (4a) appeared the most likely in the solid state, existed in dimethyl sulphoxide solution nearly exclusively as 3',4'-dihydro-3'-oxospiro-4-carboxylic acid (18).The equilibrium (4a) (18) was strongly influenced by the nature of the solvent.A study of the behaviour of compounds (5)-(10) enabled us to establish that the spirocyclisation critically depends on both the nature of the substituents on the pyridazine ring and on the nucleophilicity of the group bonded to the phenyl ring.
