نتایج جستجو برای: n disubstituted urea
تعداد نتایج: 1007367 فیلتر نتایج به سال:
A versatile and highly efficient synthesis of monosubstituted ureas is described. The reaction of an amine with 4-nitrophenyl-N-benzylcarbamate, followed by hydrogenolysis, provides the corresponding urea in high yield and purity. This carbamate can also be employed for the derivatization of water-soluble polyamines (e.g. aminoglycoside antibiotics), while other reagents (e.g. benzylisocyanate)...
In the title compound, C(7)H(7)BrN(2)O, both the urea moiety [maximum deviation 0.003 (2) Å] and the benzene ring are essentially planar [maximum deviation 0.003 (2) Å] but are rotated with respect to each other by a dihedral angle of 47.8 (1)°. The crystal assembly is stabilized by N-H⋯O hydrogen bonds between all NH protons as conventional hydrogen bond donors and the C=O oxygen as a trifurca...
1,2-Disubstituted 1,2,3,4-tetrahydrobenz[g]isoquinoline-5,10-diones are prepared for the first time through an activated Pictet-Spengler reaction of the corresponding imines of 2-(1,4-dimethoxynaphth-2-yl)ethylamine in the presence of an acyl chloride and AlCl(3) followed by an oxidation with silver(II) oxide in nitric acid. Depending on the reaction conditions the N-trichloroacetyl protecting ...
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