Premium
A new tautomeric zwitterion form of 2‐acylamino‐4 H ‐1,3,4‐oxadiazino[5,6‐ b ]quinoxalines in solution
Author(s) -
Kurasawa Yoshihisa,
Mitomi Takako,
Okamoto Yoshihisa,
Kim Ho Sik
Publication year - 1998
Publication title -
journal of heterocyclic chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.321
H-Index - 59
eISSN - 1943-5193
pISSN - 0022-152X
DOI - 10.1002/jhet.5570350617
Subject(s) - tautomer , chemistry , zwitterion , methyl iodide , medicinal chemistry , dimethyl sulfoxide , sulfoxide , base (topology) , iodide , organic chemistry , molecule , mathematical analysis , mathematics
The reaction of 2‐acyiamino‐8‐chloro‐4‐methyl‐4 H ‐1,3,4‐oxadiazino[5,6‐ b ]quinoxalines 2a‐d with methyl iodide/base gave the 8‐chloro‐4,10‐dimethyl‐4 H ‐1,3,4‐oxadiazino[5,6‐ b ]quinoxalin‐10‐ium‐2‐acylamidates 4a‐d , respectively. Comparison of the nmr spectral data between compounds 2a‐d and 4a‐d in deuteriodimethyl sulfoxide or in deuteriotrifluoroacetic acid established that compounds 2a‐d existed as the zwitterionic tautomers 2′a‐d in solution.