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.
Ir,uv和1 H nmr光谱证据表明,两性离子结构(4a)最可能以固态形式存在的5-(邻氨基苯基氨基甲酰基)哒嗪-4-羧酸(4)存在于二甲基亚砜中溶液几乎完全成为3',4'-二氢-3'-氧代螺[哒嗪5(2 ħ),2' - (1' ħ) -喹喔啉] -4-羧酸(18)。平衡(4a)⇄(18)受溶剂性质的强烈影响。对化合物(5)-(10)行为的研究使我们能够确定,螺环化主要取决于哒嗪环上取代基的性质以及与苯环键合基团的亲核性。
CHIMICHI S.; NESI R.; SCOTTON M.; MANNUCCI C.; ADEMBRI G., J. CHEM. SOC. PERKIN TRANS., 1980, PART 2, NO 9, 1339-1343
作者:CHIMICHI S.、 NESI R.、 SCOTTON M.、 MANNUCCI C.、 ADEMBRI G.