Solving Crystal Structures from Powder Data: The Use of a Molecular Fragment

Altomare, Angela; Giacovazzo, Carmelo; Guagliardi, Antonietta; Moliterni, Anna

doi:10.4028/www.scientific.net/msf.278-281.289

Cited by 1 publication

(2 citation statements)

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“…1 3 C NMR: 24.86;62.2;123.6;123.9;127.6;127.7;128.7;129.2;129.5;130.4;130.8;131.5;132.0;134.0;147.3;148.8;155.1;166.0 ,3.19;N,14.77. Found: C,50.53;H,3.13;N,14.50.…”

Section: -[ -C Y a N O --( 4 -N I T R O P H E N Y L ) E T H Y L ] -3 unclassified

“…The X-ray data were collected on the Nonius KappaCCD Synthesis of New Substituted 5-Methyl-3,5-diphenylimidazolidine-2,4-diones Jul-Aug 2005 901 diffractometer, MoKα radiation (λ = 0.71073 Å, graphite monochromator) at 150(2) K. Absorption corrections were carried out for both data sets using a multiscan procedure (SORTAV) [13]. The structure was solved by direct methods (SIR92) [14], full-matrix least-squares refinements on F 2 were carried out using the program SHELXL97 [15]. All non-hydrogen atoms are refined anisotropically, all hydrogen atoms on carbons were calculated into idealised positions (riding model) and assigned displacement factors H iso (H) = 1.2 U eq (pivot atom) or of 1.5U eq for the methyl moiety.…”

Section: Introductionmentioning

confidence: 99%

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Synthesis of new substituted 5‐methyl‐3,5‐diphenylimidazolidine‐2,4‐diones from substituted 1‐(1‐cyanoethyl‐1‐phenyl)‐3‐phenylureas

Sedlák¹,

Keder²,

Hanusek³

et al. 2005

Journal of Heterocyclic Chem

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The reaction of substituted phenyl isocyanates with 2-amino-2-phenylpropanenitrile and 2-amino-2-(4-nitrophenyl)propanenitrile has been used to prepare substituted 1-(1-cyanoethyl-1-phenyl)-3-phenylureas. In anhydrous phosphoric acid the first products to be formed from 1-(1-cyanoethyl-1-phenyl)-3-phenylureas are phosphates of 4-methyl-4-phenyl-2-phenylimino-5-imino-4,5-dihydro-1,3-oxazoles, which on subsequent hydrolysis give the respective ureidocarboxylic acids. On prolongation of the reaction time, the phosphates of 4-methyl-4-phenyl-2-phenylimino-5-imino-4,5-dihydro-1,3-oxazoles rearrange to give phosphates of 5-methyl-4-imino-3,5-diphenylimidazolidin-2-ones, and these are subsequently hydrolysed to the respective substituted 5-methyl-3,5-diphenylimidazolidin-2,4-diones. The ureidocarboxylic acids were also prepared by alkaline hydrolysis of 5-methyl-3,5-diphenylimidazolidin-2,4-diones. The 5-methyl-3,5-diphenylimidazolidin-2,4-diones and ureidocarboxylic acids were characterised by their 1 H and 13 C NMR spectra. Structure of the 5-methyl-5-(4-nitrophenyl)-3-phenylimidazolidine-2,4-dione was verified by X-ray d i ffraction. The alkaline hydrolysis of individual imidazolidine-2,4-diones was studies spectrophotometrically in sodium hydroxide solutions at 25 °C. The rate-limiting step of the base catalysed hydrolysis consists in decomposition of the tetrahedral intermediate. The reaction is faster if electron-acceptor substituents are present in the 3-phenyl group of imidazolidine-2,4-dione cycle. The pK a values of individual 5-methyl-3,5-diphenylimidazolidine-2,4-diones have been determined kinetically.

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“…1 3 C NMR: 24.86;62.2;123.6;123.9;127.6;127.7;128.7;129.2;129.5;130.4;130.8;131.5;132.0;134.0;147.3;148.8;155.1;166.0 ,3.19;N,14.77. Found: C,50.53;H,3.13;N,14.50.…”

Section: -[ -C Y a N O --( 4 -N I T R O P H E N Y L ) E T H Y L ] -3 unclassified

Section: Introductionmentioning

confidence: 99%