作者:Wolfgang Holzer、Gernot A. Eller、Simeon Sch嗜berger
DOI:10.3987/com-07-11177
日期:——
Detailed NMR spectroscopic investigations ((1)H, (13)C, (15)N) with cinnolin-4-ol (1) reveal this compound to exist exclusively in the 77 cinnolin-4(1H)-one form in deuteriodimethyl sulfoxide solution. This finding is confirmed by comparison of the NMR spectroscopic data of 1 with those of the corresponding 'fixed' O-methyl and N-methyl derivatives, i.e. 4-methoxycinnoline (3) and 1-methylcinnolin-4(1H)-one (5). Similarly, cinnoline-4-thiol (4) is present in the thione form in deuteriodimethyl sulfoxide, whereas cinnolin-4-amine (7) exists in the amino form. In addition, in-depth analyses of the NMR spectra of some simple 4-substituted cinnolines are provided.