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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.

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.


The mol­ecular structure of (III) showing 50% displacement ellipsoids. Only one orientation of the disordered O2—H2 group is shown.
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fig3: The mol­ecular structure of (III) showing 50% displacement ellipsoids. Only one orientation of the disordered O2—H2 group is shown.

Mentions: Compound (III), shown in Fig. 3 ▸, crystallizes in a centrosymmetric space group, indicating that racemization of C10 has occurred during the methyl­ation of N2: the C10 atom in the asymmetric unit was arbitrarily assigned an S configuration. The O2—H2 hy­droxy group is disordered over two orientations in a 0.802 (7):0.198 (7) ratio. The geometric parameters for (III) are largely consistent with those for (I) and (II): the C7/N1/N2/C9/O1 grouping (r.m.s. deviation = 0.014 Å) subtends a dihedral angle of 1.9 (4)° with the C1–C6 benzene ring and the C9—N2 and N1—N2 bond lengths are 1.358 (5) and 1.381 (4) Å, respectively. The C7—N1—N2—C8 torsion angle is 0.8 (5)° and the C9—C10—C11—O2A (major disorder component) torsion angle is −54.9 (4)°. The C9—C10—C11—O2B torsion angle for the minor disorder component is −156.7 (8)°, which has a significant role to play in the hydrogen-bonding pattern in the crystal of (III).


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)

The mol­ecular structure of (III) showing 50% displacement ellipsoids. Only one orientation of the disordered O2—H2 group is shown.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

fig3: The mol­ecular structure of (III) showing 50% displacement ellipsoids. Only one orientation of the disordered O2—H2 group is shown.
Mentions: Compound (III), shown in Fig. 3 ▸, crystallizes in a centrosymmetric space group, indicating that racemization of C10 has occurred during the methyl­ation of N2: the C10 atom in the asymmetric unit was arbitrarily assigned an S configuration. The O2—H2 hy­droxy group is disordered over two orientations in a 0.802 (7):0.198 (7) ratio. The geometric parameters for (III) are largely consistent with those for (I) and (II): the C7/N1/N2/C9/O1 grouping (r.m.s. deviation = 0.014 Å) subtends a dihedral angle of 1.9 (4)° with the C1–C6 benzene ring and the C9—N2 and N1—N2 bond lengths are 1.358 (5) and 1.381 (4) Å, respectively. The C7—N1—N2—C8 torsion angle is 0.8 (5)° and the C9—C10—C11—O2A (major disorder component) torsion angle is −54.9 (4)°. The C9—C10—C11—O2B torsion angle for the minor disorder component is −156.7 (8)°, which has a significant role to play in the hydrogen-bonding pattern in the crystal of (III).

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.