13589-74-7Relevant articles and documents
Amidino substituted 2-aminophenols: biologically important building blocks for the amidino-functionalization of 2-substituted benzoxazoles
Pti?ek, Lucija,Hok, Lucija,Grb?i?, Petra,Topi?, Filip,Cetina, Mario,Rissanen, Kari,Paveli?, Sandra Kraljevi?,Vianello, Robert,Racané, Livio
supporting information, p. 2784 - 2793 (2021/04/07)
Unlike the closely related and widely investigated amidino-substituted benzimidazoles and benzothiazoles with a range of demonstrated biological activities, the matching benzoxazole analogues still remain a largely understudied and not systematically evaluated class of compounds. To address this challenge, we utilized the Pinner reaction to convert isomeric cyano-substituted 2-aminophenols into their amidine derivatives, which were isolated as hydrochlorides and/or zwitterions, and whose structure was confirmed by single crystal X-ray diffraction. The key step during the Pinner synthesis of the crucial carboximidate intermediates was characterized through mechanistic DFT calculations, with the obtained kinetic and thermodynamic parameters indicating full agreement with the experimental observations. The obtained amidines were subjected to a condensation reaction with aryl carboxylic acids that allowed the synthesis of a new library of 5- and 6-amidino substituted 2-arylbenzoxazoles. Their antiproliferative features against four human tumour cell lines (SW620, HepG2, CFPAC-1, HeLa) revealed sub-micromolar activities on SW620 for several cyclic amidino 2-naphthyl benzoxazoles, thus demonstrating the usefulness of the proposed synthetic strategy and promoting amidino substituted 2-aminophenols as important building blocks towards biologically active systems.
Selective nitration of phenol derivatives
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, (2008/06/13)
Process for preparing 4-nitrophenol derivatives of formula (IV) with high selectivity, which comprises converting phenols to diphenyl oxalate derivatives of formula (III) and conducting nitration reaction and hydrolysis to give said 4-nitrophenol derivatives. STR1 In the above formulae, R is, the same or different from each other, an alkyl group having 1 to 4 carbon atoms; a halogen atom; an alkoxy group having 1 to 4 carbon atoms; a formyl group; a nitrile group; --COOR1 (R1 is an alkyl group having 1 to 4 carbon atoms); --CONR2 R3 (R2 and R3 are, the same or different from each other, hydrogen atom(s) or alkyl group(s) having 1 to 4 carbon atoms); or --COR4 (R4 is an alkyl group having 1 to 4 carbon atoms), and R is not substituted at the 4-position of the phenyl ring and not substituted at the 2- and 6-positions of the phenyl ring at the same time, and, n is 1, 2 or 3.
STUDIES ON THE TWO-PHASE NITRATION OF PHENOLS (part 2)
Thompson, Malcolm J.,Zeegers, Petrus J.
, p. 2661 - 2674 (2007/10/02)
Gas phase Ionization Potentials can be correlated with solution Oxidation Potentials for phenols and used to predict the likelihood of successful nitration using the two-phase procedure.The interaction of steric and electronic effects then determines the sites of nitration by radical recombination of the phenoxy radical and NO2.Nitration of dioxybenzenes may give insights into the nitration mechanism.
