85106-95-2Relevant academic research and scientific papers
1,8-Naphthyridines and their use as antibacterial agents
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, (2008/06/13)
Novel quinoline-, naphthyridine-, and benzoxazine-carboxylic acid derivatives with bridged sidechains useful as antibacterial agents are described. Methods for their preparation, formulation, and use in treatment of bacterial infections is also described.
Lithiation of Bridgehead Position in 3,6-Bridged Piperazine-2,5-diones
Eastwood, Frank W.,Gunawardana, Dionne,Wernert, Gregory T.
, p. 2289 - 2298 (2007/10/02)
2,5-Dimethyl-2,5-diazabicyclooctane-3,6-dione can be lithiated at the 1,4 (bridgehead) positions with 2 equiv. of butyllithium at -78 deg C and deuterated with D2O (D0, 11.2; D1, 56.1; D2, 30.1percent).With butyllithium and methyl iodide the 1,2,5-trimethyl and 1,2,4,5-tetramethyl derivatives are obtained.Treatment of dimethyl 2,6-diaminoheptanedioate dihydrochloride with sodium methoxide in boiling butanol gives 6,8-diazabicyclononane-7,9-dione in 62percent yield.N-Methylation of this compound yields 6,8-dimethyl-6,8-diazabicyclononane-7,9-dione which can similarly be lithiated at the 1,5 (bridgehead) positions and deuterated with D2O (D0, 5.6; D1, 70.8; D2, 23.6percent).Lithiation with butyllithium and reaction with methyl iodide, benzyl iodide or bromomethyl methyl ether gives mono- and di-alkylated products at the 1,5-position.The ability to lithiate the bridgehead positions in these compounds is attributed primarily to a combination of the inductive effect of the carbonyl group and dipole stabilization by the amide nitrogen.
