6139-61-3Relevant academic research and scientific papers
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.
Highly selective deprotection of tert-butyl esters using ytterbium triflate as a catalyst under mild conditions
Sridhar, P. Ramu,Sinha, Surajit,Chandrasekaran
, p. 157 - 160 (2007/10/03)
Ytterbium triflate catalyses the deprotection of tert-butyl esters selectively in the presence of other esters under mild conditions in almost quantitative yields. The reactions are carried out in nitromethane (45°-50°C) using 5 mole percent of the catalyst.
