1-(2-Aminoethyl)-3-phenylthiourea

In the crystal structure of the title compound, C9H13N3S, molecules are linked through N—H⋯S and N—H⋯N hydrogen bonds, forming hydrogen-bonded tapes along the b axis. The dihedral angle between the phenyl ring and the thiourea group is 44.9 (2)°.

In the crystal structure of the title compound, C 9 H 13 N 3 S, molecules are linked through N-HÁ Á ÁS and N-HÁ Á ÁN hydrogen bonds, forming hydrogen-bonded tapes along the b axis. The dihedral angle between the phenyl ring and the thiourea group is 44.9 (2) .

Comment
Thioureas have been employed as ligands for metal complexes used in asymetric catalytic hydrogenation (Tommasino et al., 1999(Tommasino et al., , 2000 as well as synthetic anion hosts (Leung et al., 2008). A number of single-crystal X-ray structures have been reported demonstrating a range of inter-and intra molecular hydrogen bonding motifs (Guo, 2007) and (Okino et al., 2005).
The title compound is commercially available, but its structure determination ( Fig. 1) has not been reported previously.
In the crystal, molecules are linked through intermolecular N-H···S and N-H···N hydrogen bonds (Table 1), forming hydrogen-bonded tapes lying parallel to the b axis (Fig. 2). The closest structural analogues all demonstrate intramolecular hydrogen bonding. The hydrogen atoms of the primary amino group are not involved in any short intermolecular contact.

Experimental
The title compound was synthesized as reported by Lee et al. (1985). A solution of phenyl isothiocyanate (6.75 g, 50 mmole) in diethylether (15 ml) was added dropwise at 15°C to a vigorously stirred solution of anhydrous ethylenediamine (6.01 g, 100 mmole) in isopropyl alcohol (100 ml) over a period of 30 min. The reaction mixture was stirred for 2 hrs at room temperature and quenched with water (200 ml). The reaction mixture was maintained overnight at room temperature. Then the reaction mixture was acidified with conc. HCl up to a pH of 2.6. The solvents were evaporated under vacuum and the residue was suspended in hot water for 30 min and the resulting precipitate was filtered. The filtrate was basified by the addition of caustic lye, and a precipitate formed. This in turn was filtered, washed with ice cold water and dried. The yield was 5.06 g. (75%).
Crystals suitable for single-crystal X-ray diffraction were grown by slow evaporation from ethyl acetate at room temperature. M.p. = 408-409 K.

Refinement
With the exception of those involved in hydrogen bonding, all hydrogen atoms were first located in the difference map then positioned geometrically and allowed to ride on their respective parent atoms with C-H = 0.95 Å and U iso (H) = 1.2U eq (C) for aromatic and C-H = 0.99 Å and U iso (H) = 1.2U eq (C) for CH 2 hydrogen atoms. Hydrogen atoms involved in hydrogen bonding were located in the difference map and refined freely.
supplementary materials sup-2 Figures   Fig. 1. The molecular structure of the title compound. Displacement elipsoids are drawn at 40% probability. Hydrogen atoms are shown as spheres of arbitrary radii.  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.