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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 (I). Symmetry code: (i) 1 + x, y, z. All C-bound H atoms are omitted for clarity.
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fig4: Fragment of a [100] hydrogen-bonded chain in the crystal of (I). Symmetry code: (i) 1 + x, y, z. All C-bound H atoms are omitted for clarity.

Mentions: In the extended structure of (I), the mol­ecules are linked by short O2—H2A⋯O4i (i = 1 + x, y, z) and much longer N3—H3A⋯O4i hydrogen bonds (Table 1 ▸, Fig. 4 ▸) to the same acceptor oxygen atom, generating [100] chains, with adjacent mol­ecules related by simple translation in the a-axis direction. An unusual (7) loop arises from these hydrogen bonds; alternately, this could be described as combined C(7) O—H⋯O and C(4) N—H⋯O chains. A pair of weak C—H⋯π inter­actions are also observed but there is no aromatic π–π stacking (shortest centroid–centroid separation > 4.7 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 (I). Symmetry code: (i) 1 + x, y, z. All C-bound H atoms are omitted for clarity.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig4: Fragment of a [100] hydrogen-bonded chain in the crystal of (I). Symmetry code: (i) 1 + x, y, z. All C-bound H atoms are omitted for clarity.
Mentions: In the extended structure of (I), the mol­ecules are linked by short O2—H2A⋯O4i (i = 1 + x, y, z) and much longer N3—H3A⋯O4i hydrogen bonds (Table 1 ▸, Fig. 4 ▸) to the same acceptor oxygen atom, generating [100] chains, with adjacent mol­ecules related by simple translation in the a-axis direction. An unusual (7) loop arises from these hydrogen bonds; alternately, this could be described as combined C(7) O—H⋯O and C(4) N—H⋯O chains. A pair of weak C—H⋯π inter­actions are also observed but there is no aromatic π–π stacking (shortest centroid–centroid separation > 4.7 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.