An improved synthesis of N1-carbomethoxylated indolylindolines 2 from 5-substituted indoles 1, by replacing the previously employed strong acids or toxic metals with t-BuNH 2 /MeOCOCl in CH 2 Cl 2 /H 2 O, is described. The substituent effect of electron donor or acceptor groups was examined, revealing that electron-deficient indoles are less reactive to dimerization than electron-rich indoles, with 5-cyano and 5-nitroindoles leading to no reaction. A dynamic process caused by the restricted rotation of the N-CO 2 Me bond of 2 was evidenced by 1 H NMR measurements.
Deprotection O 0345Cleavage of Alkoxycarbonyl Protecting Groups from Carbamates by t-BuNH2.-A simple and efficient removal is achieved by treatment with excess tBu-NH 2 in refluxing methanol. Base-sensitive groups like esters and nitriles remain unchanged under these conditions. - (SUAREZ-CASTILLO*, O. R.; MONTIEL-ORTEGA, L. A.; MELENDEZ-RODRIQUEZ, M.; SANCHEZ-ZAVALA, M.; Tetrahedron Lett. 48 (2007) 1, 17-20; Cent. Invest. Quim., Univ. Auton. Estado Hidalgo, 42001 Pachuca Hidalgo, Mex.; Eng.) -Mais 15-038
Microwave-Assisted Synthesis of 3,1-Benzoxazin-2-ones from 3-Hydroxyoxindoles. -Title compounds (IV), (V) and (VI) are synthesized starting from 3-hydroxyindoles (I) in a two-step sequence. -(SUAREZ-CASTILLO*, O. R.; BAUTISTA-HERNANDEZ, C. I.; SANCHEZ-ZAVALA, M.; MELENDEZ-RODRIGUEZ, M.; SIERRA-ZENTENO, A.; MORALES-RIOS, M. S.; JOSEPH-NATHAN, P.; Heterocycles 85 (2012) 9, 2147-2171, http://dx.doi.org/10.3987/com-12-12472 ; Area Acad. Quim., Univ. Auton. Estado Hidalgo, 42184 Hidalgo, Mex.; Eng.) -R. Langenstrassen 03-163
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