meso-N,N′-Oxalyldivaline

Abstract

The title compound, 2,2'-(oxalyldiimino)bis(3-methylbutanoic acid), C12H20N2O6, possesses a centre of symmetry. In the crystal, molecules are connected by hydrogen bonds between oxamide and carboxyl groups, similar to the pattern of the monoclinic forms of HO-Gly-CO-CO-Gly-OH and HO-Aib-CO-CO-Aib-OH (Gly is glycine and Aib is 2-aminoisobutyric acid). The characteristic torsion angles in the title compound are close to those in peptide alpha-helices.

N,N′-Bis[2-(dimethylammonio)ethyl]oxamide dinitrate

“…1). The six non-H atoms of the oxamide group are almost coplanar, which is similar to other oxamide compounds (Su et al, 1999;Perić et al, 2001). The C5-C5 i distance [symmetry code: (i) 1 À x, 1 À y, 2 À z] of 1.541 (3) Å is somewhat longer than the analogous bond in the copper complex of the deprotonated parent oxamide [1.518 (5) Å ; Real et al, 1993].…”

2-{N′-[3-(Dimethylammonio)propyl]oxamido}benzoate

“…There is an intramolecular hydrogen bond between amido nitrogen atom (N1) and carboxyl oxygen atom (O2). The zwitterion has a transoid conformation, and six atoms of oxamido group are almost coplanar, which is similar to other oxamido compounds (Perić et al, 2001;Su et al, 1999;Sun et al, 2006). The dihedral angle between the oxamide and the benzene ring is 27.05 (12)°, and that between the benzene ring and carboxyl group is 23.9 (4)°.…”

“…For general background, see: Ojima & Nonoyama (1988); Matović et al (2005); Pei et al (1991); Zang et al (2003). For related structures, see: Perić et al (2001); Su et al (1999); Sun et al (2006). For synthesis, see: Matović et al (2005).…”

The twinned crystal structure of rac-(R,R)-N,N′-oxalyldivalinol

“…The present structure determination forms part of a systematic study related to hydrogen bonding and gelation properties of bis(amino acid) Peric  et al, 2001) and bis(amino alcohol) oxamide derivatives (Makarevic  et al, 2003). Fig.…”