4376-19-6Relevant articles and documents
Synthesis of New Dialkyl 2,2′-[Carbonyl bis (azanediyl)]dibenzoates via Curtius Rearrangement
Yassine, Hasna,Bouali, Jamila,Oumessaoud, Asmaa,Ourhzif, El Mahdi,Hamri, Salha,Hafid, Abderrafia,Khouili, Mostafa,Pujol, Maria Dolors
, p. 1971 - 1979 (2021/01/21)
The 2-(alkylcarbonyl)benzoic acids obtained by esterification of phthalic anhydride are converted into azide derivatives: alkyl 2-[(azidocarbonyl)amino]benzoates and to ureas: dialkyl 2,2′-[carbonyl bis (azanediyl)]dibenzoates. These transformations were carried out using classical Curtius rearrangement conditions in the presence of diphenylphosphoryl azide (DPPA) in a basic medium, followed by hydrolysis. Subsequently, a final condensation reaction of these urea derivatives enabled us to obtain, for the first time, the new alkyl derivatives, alkyl 2-[2,4-dioxo-1,2-dihydroquinazolin-3(4 H)-yl]benzoates. All the new compounds obtained in satisfactory yields were characterized by 1H and 13C NMR, and by X-ray crystallographic analysis.
Practical selective monohydrolysis of bulky symmetric diesters: Comparing with sonochemistry
Shi, Jianjun,Zhao, Tian,Niwayama, Satomi
, p. 6815 - 6820 (2018/10/20)
The conditions of the practical selective monohydrolysis of symmetric diesters we previously reported have been modified and applied to selective monohydrolysis of bulky symmetric diesters. While ultrasound is generally considered effective for two-phase reactions, its effect actually turned out to be rather marginal. Instead, use of a larger proportion of a polar aprotic co-solvent, DMSO, and aqueous KOH helped enhance the reaction rates and improve the yields of the half-esters. The reactions are simple, mild and practical without special devices.