Deacetyl tenuazonic acid p-toluenesulfonylhydrazone

The title compound {systematic name: 4-methyl-N′-[(3E)-2-(1-methylpropyl)-5-oxopyrrolidin-3-ylidene]benzenesulfonohydrazide}, C15H21N3O3S, is the condensation product of deacetyl tenuazonic acid (DTA) and p-toluenesulfonohydrazide. The crystal structure consists of chains along [100] linked by N—H⋯O hydrogen bonds.

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: SJ2674).  (Stickings, 1959). As TA is frequently encountered in various food matrices (Weidenbörner, 2001), traces of DTA are expected to occur in these matrices as well. We have recently reported a derivatization procedure for TA quantification in food, which is based on hydrazone formation with 2,4-dinitrophenylhydrazine (Siegel, Rasenko et al., 2009) and are currently evaluating a similar procedure for DTA quantification using p-toluenesulfonyl hydrazide. The title compound is the product of the latter derivatization reaction. The stucture of the title compound, (I), is shown below. Each molecule ( Fig.1) is connected to three adjacent molecules via N-H···O hydrogen bonds. As a result isolated ribbons are formed along the a axis, as depicted in Fig. 2.

Experimental
DTA was supplied by the workgroup of Professor R. Faust (University of Kassel, Germany) by synthesis according to a literature procedure (Lebrun et al., 1988). Its identity was confirmed by x-ray crystallography (Siegel, Kochet al., 2009).
The title compound was synthesized by dissolving 20 mg (1 eq., 0.13 mmol) of DTA and a five fold molar excess of p-toluenesulfonyl hydrazide (5 eq., 0.65 mmol, 121 mg) in 50 ml 2 M HCl. After 30 minutes of shaking the precipitate was collected, washed with water, dissolved in ethyl acetate and dried with sodium sulfate. After evaporation of the solvent, a yellow powder was obtained, which was recrystallized from ethanol twice. For single-crystal x-ray crystallography, orange crystals of the title compound were grown by solvent evaporation (methanol:water 50:50 v:v) at ambient temperature over a period of three weeks.

Refinement
All non-hydrogen atoms were refined anisotropically. The hydrogen atoms were located in difference maps but positioned with idealized geometry and refined using the riding model,with C-H = 0.98-1 Å or N-H = 0.9 Å and U iso (H) = 1.2 U eq (C, N) or 1.5 U eq (C methyl ). Fig. 1. The structure of the title compound with labelling and displacement ellipsoids drawn at the 50% probability level.

Figures
supplementary materials sup-2  as those based on F, and R-factors based on ALL data will be even larger.