2-Amino-2,3-dimethylbutanamide

The title compound, C6H14N2O, was synthesized by the reaction between 2-amino-2,3-dimethylbutanonitrile and oil of vitriol (sulfuric acid). A racemic mixture of L- and R-2-amino-2,3-dimethylbutanamide was characterized crystallographically. In the crystal structure, intermolecular N—H⋯O hydrogen bonds link the two enantiomers into a three-dimensional network.

The title compound, C 6 H 14 N 2 O, was synthesized by the reaction between 2-amino-2,3-dimethylbutanonitrile and oil of vitriol (sulfuric acid). A racemic mixture of L-and R-2amino-2,3-dimethylbutanamide was characterized crystallographically. In the crystal structure, intermolecular N-HÁ Á ÁO hydrogen bonds link the two enantiomers into a threedimensional network.

Structure Reports Online
Experimental 2-Amino-2,3-dimethylbutanenitrile liquid (46.7 g, 0.417 mol) was added to the oil of vitriol solution (104.2 ml) under N 2 protection in cold water bath. Next, the solution along with the white solid appeared was slowly poured into 150 grams of ice water after three days of stir at room temperature. Then, Na 2 CO 3 (221 g) and 50% NaOH (38 ml) were consumed to basify the solution to pH value 9.0, giving rise to plenty of white solid. The title compound (25.8 g) with a m.p of 76-80 degrees, yielding 47.6% was obtained after filtration and purification through extraction with dichloromethane. The suitable single crystals for X-ray diffraction was from slow evaporation of solvent from the title compound dichloromethane solution.

Refinement
H atoms bonded to O atom of free water molecule were located in a difference map. All the other H atoms were placed in calculated positions and refined as riding, with C-H = 0.96-0.98 Å, and O-H = 0.85 Å, and U iso (H) = 1.2 or 1.5U eq (C,O). Fig. 1. The molecular structure with atom labels and 30% probability displacement ellipsoids for non-H atoms.

Special details
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating Rfactors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.