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Different hydrogen-bonded chains in the crystal structures of three alkyl N-[(E)-1-(2-benzyl-idene-1-methyl-hydrazin-yl)-3-hy-droxy-1-oxopropan-2-yl]carbamates.

Noguiera TC, Pinheiro AC, Wardell JL, de Souza MV, Abberley JP, Harrison WT - Acta Crystallogr E Crystallogr Commun (2015)

Bottom Line: The crystal structures of three methyl-ated hydrazine carbamate derivatives prepared by multi-step syntheses from l-serine are presented, namely benzyl N-{(E)-1-[2-(4-cyanobenzylidene)-1-methylhydrazinyl]-3-hydroxy-1-oxopro-pan-2-yl}carbamate, C20H20N4O4, tert-butyl N-{(E)-1-[2-(4-cyanobenzylidene)-1-methylhydrazinyl]-3-hydroxy-1-oxopropan-2-yl}carbamate, C17H22N4O4, and tert-butyl N-[(E)-1-(2-benzylidene-1-methylhydrazinyl)-3-hydroxy-1-oxopro-pan-2-yl]carbamate, C16H23N3O4.One of them shows that an unexpected racemization has occurred during the mild-condition methyl-ation reaction.In each crystal structure, the mol-ecules are linked into chains by O-H⋯O hydrogen bonds, but with significant differences between them.

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Affiliation: Fundação Oswaldo Cruz, Instituto de Tecnologia em Fármacos-FarManguinhos, Rua Sizenando Nabuco, 100, Manguinhos, 21041-250 Rio de Janeiro, RJ, Brazil.

ABSTRACT
The crystal structures of three methyl-ated hydrazine carbamate derivatives prepared by multi-step syntheses from l-serine are presented, namely benzyl N-{(E)-1-[2-(4-cyanobenzylidene)-1-methylhydrazinyl]-3-hydroxy-1-oxopro-pan-2-yl}carbamate, C20H20N4O4, tert-butyl N-{(E)-1-[2-(4-cyanobenzylidene)-1-methylhydrazinyl]-3-hydroxy-1-oxopropan-2-yl}carbamate, C17H22N4O4, and tert-butyl N-[(E)-1-(2-benzylidene-1-methylhydrazinyl)-3-hydroxy-1-oxopro-pan-2-yl]carbamate, C16H23N3O4. One of them shows that an unexpected racemization has occurred during the mild-condition methyl-ation reaction. In each crystal structure, the mol-ecules are linked into chains by O-H⋯O hydrogen bonds, but with significant differences between them.

No MeSH data available.


Fragment of a [100] hydrogen-bonded chain in the crystal of (II). Symmetry code: (i) 1 + x, y, z. All C-bound H atoms are omitted for clarity.
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fig5: Fragment of a [100] hydrogen-bonded chain in the crystal of (II). Symmetry code: (i) 1 + x, y, z. All C-bound H atoms are omitted for clarity.

Mentions: The extended structure of (II) also features [100] chains (Fig. 5 ▸) with adjacent mol­ecules related by translation, but in this case the mol­ecules are only linked by C(7) O2—H2A⋯O4i (i = 1 + x, y, z) hydrogen bonds (Table 2 ▸) with almost the same local geometry as seen in (I). The N3—H3 grouping in (II) is twisted far enough away from O4i to not form an inter­molecular hydrogen bond (H3⋯O4i = 3.2 Å), but instead forms an intra­molecular link to O1. A very long inter­molecular C—H⋯N inter­action is observed but there is no π–π stacking in (II), as the shortest centroid–centroid separation is greater than 5.3 Å.


Different hydrogen-bonded chains in the crystal structures of three alkyl N-[(E)-1-(2-benzyl-idene-1-methyl-hydrazin-yl)-3-hy-droxy-1-oxopropan-2-yl]carbamates.

Noguiera TC, Pinheiro AC, Wardell JL, de Souza MV, Abberley JP, Harrison WT - Acta Crystallogr E Crystallogr Commun (2015)

Fragment of a [100] hydrogen-bonded chain in the crystal of (II). Symmetry code: (i) 1 + x, y, z. All C-bound H atoms are omitted for clarity.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4518986&req=5

fig5: Fragment of a [100] hydrogen-bonded chain in the crystal of (II). Symmetry code: (i) 1 + x, y, z. All C-bound H atoms are omitted for clarity.
Mentions: The extended structure of (II) also features [100] chains (Fig. 5 ▸) with adjacent mol­ecules related by translation, but in this case the mol­ecules are only linked by C(7) O2—H2A⋯O4i (i = 1 + x, y, z) hydrogen bonds (Table 2 ▸) with almost the same local geometry as seen in (I). The N3—H3 grouping in (II) is twisted far enough away from O4i to not form an inter­molecular hydrogen bond (H3⋯O4i = 3.2 Å), but instead forms an intra­molecular link to O1. A very long inter­molecular C—H⋯N inter­action is observed but there is no π–π stacking in (II), as the shortest centroid–centroid separation is greater than 5.3 Å.

Bottom Line: The crystal structures of three methyl-ated hydrazine carbamate derivatives prepared by multi-step syntheses from l-serine are presented, namely benzyl N-{(E)-1-[2-(4-cyanobenzylidene)-1-methylhydrazinyl]-3-hydroxy-1-oxopro-pan-2-yl}carbamate, C20H20N4O4, tert-butyl N-{(E)-1-[2-(4-cyanobenzylidene)-1-methylhydrazinyl]-3-hydroxy-1-oxopropan-2-yl}carbamate, C17H22N4O4, and tert-butyl N-[(E)-1-(2-benzylidene-1-methylhydrazinyl)-3-hydroxy-1-oxopro-pan-2-yl]carbamate, C16H23N3O4.One of them shows that an unexpected racemization has occurred during the mild-condition methyl-ation reaction.In each crystal structure, the mol-ecules are linked into chains by O-H⋯O hydrogen bonds, but with significant differences between them.

View Article: PubMed Central - HTML - PubMed

Affiliation: Fundação Oswaldo Cruz, Instituto de Tecnologia em Fármacos-FarManguinhos, Rua Sizenando Nabuco, 100, Manguinhos, 21041-250 Rio de Janeiro, RJ, Brazil.

ABSTRACT
The crystal structures of three methyl-ated hydrazine carbamate derivatives prepared by multi-step syntheses from l-serine are presented, namely benzyl N-{(E)-1-[2-(4-cyanobenzylidene)-1-methylhydrazinyl]-3-hydroxy-1-oxopro-pan-2-yl}carbamate, C20H20N4O4, tert-butyl N-{(E)-1-[2-(4-cyanobenzylidene)-1-methylhydrazinyl]-3-hydroxy-1-oxopropan-2-yl}carbamate, C17H22N4O4, and tert-butyl N-[(E)-1-(2-benzylidene-1-methylhydrazinyl)-3-hydroxy-1-oxopro-pan-2-yl]carbamate, C16H23N3O4. One of them shows that an unexpected racemization has occurred during the mild-condition methyl-ation reaction. In each crystal structure, the mol-ecules are linked into chains by O-H⋯O hydrogen bonds, but with significant differences between them.

No MeSH data available.