Abstract
C13H19NO2, monoclinic, P21/n (no. 14), a = 5.2692(3) Å, b = 13.8663(9) Å, c = 17.8020(13) Å, β = 93.323(6)°, V = 1298.50(15), Z = 4, Rgt(F) = 0.0590, wRref(F2) = 0.1932, T = 293 K.
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Zeitschrift für Kristallographie - New Crystal Structures
Editor-in-Chief: Huppertz, Hubert
Ed. by Reiß, Guido
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Crystal structure of tert-butyl 2-phenylethylcarbamate, C13H19NO2
Published Online: 2016-07-06 | DOI: https://doi.org/10.1515/ncrs-2016-0077
Open Access
This article offers supplementary material which is provided at the end of the article.
CCDC no.:: 1487250
The asymmetric unit of the title structure is shown in the figure. Tables 1 and 2 contain details of the measurement method and a list of the atoms including atomic coordinates and displacement parameters.
Table 1
Data collection and handling.
Table 2
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2).
Source of material
tert-Butyl 2-phenylethylcarbamate was synthesized from the reaction of 2-phenylethylamine with 1.2 equivalents of di-tert-butyl dicarbonate in the presence of 1.5 equivalents of triethylamine in dichloromethane at 0 °C for 15 minutes and then under reflux for 1 h. The crude product was purified by crystallization from hexane to give the title compound (90%) as colourless crystals, mp 56–57 °C (lit. 56.1–56.4 °C [1]; 54–55 °C [2]; 55–56 °C [3]).
Experimental details
The methylbenzene segment of the molecule is disordered and was refined with the occupancies 56(1)% and 44(1)%. The aromatic ring was constrained into a regular hexagon with C—C distances of 1.39 Å. All H atoms were placed in calculated positions and refined using a riding model. For the methyl groups, C—H bonds were fixed at 0.96 Å and Uiso(H) set to 1.5Ueq(C) with free rotation around the C—C bond. For the rest of the hydrogens, Uiso(H) was set to 1.2Ueq(C) with aromatic C—H and N—H distances of 0.93 and 0.86 Å, respectively.
Discussion
Various carbamate and thiocarbamate derivatives show antimicrobial activities [4], [5], [6] and various synthetic procedures have been reported for the production of carbamates. Convenient and efficient syntheses involve reactions of amino acids with Boc-benzotriazoles in the presence of triethylamine in aqueous acetonitrile at room temperature [7], of amines with phenyl 4,5-dichloro-6-oxopyridazine-1(6H)-carboxylate in tetrahydrofuran (THF) at room temperature [8], of nitriles with an excess of di-tert-butyl dicarbonate in the presence of a catalytic amount of nickel boride in methanol at room temperature [9], of aromatic carboxylic acids with di-tert-butyl dicarbonate in the presence of sodium azide, tetrabutylammonium bromide and zinc(II) trifluoromethanesulfonate in THF at 40 °C [10] and of nitro aromatics with excess chloroformates in the presence of zinc and ammonium chloride in aqueous THF at 0 °C [11]. High yields of substituted derivatives can be produced from regioselective lithiation of aryl carbamates using lithium reagents, at room temperature, followed by treatment of the lithium intermediates obtained in situ with electrophiles [12], [13].
The asymmetric unit of the title structure consists of one molecule with a disordered benzyl fragment. All bond lengths and angles are in the expected ranges. In the crystal structure, the amide group is involved in a N—H⋯O hydrogen bond (N⋯O distance = 3.078(2)Å, N—H⋯O angle = 153.3°) leading to the formation of C(4) chains along [100].
Acknowledgements:
The authors extend their appreciation to the College of Applied Medical Sciences Research Centre and the Deanship of Scientific Research at King Saud University for their funding of this research.
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About the article
Received: 2016-03-14
Accepted: 2016-06-22
Published Online: 2016-07-06
Published in Print: 2016-12-01
Citation Information: Zeitschrift für Kristallographie - New Crystal Structures, Volume 231, Issue 4, Pages 1105–1107, ISSN (Online) 2197-4578, ISSN (Print) 1433-7266, DOI: https://doi.org/10.1515/ncrs-2016-0077.
©2016 Gamal A. El-Hiti et al., published by De Gruyter.. This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 3.0 License. BY-NC-ND 3.0
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