2-Amino-4-ferrocenylthiazole

The crystal and molecular structure of 2-amino-4-ferrocenylthiazole has been determined. The crystal packing features intermolecular N—H⋯N and C—H⋯π interactions.

The title compound, [Fe(C 5 H 5 )(C 8 H 7 N 2 S)], was synthesized by the direct reaction of acetylferrocene, thiourea and resublimed iodine. The structure shows one molecule in the asymmetric unit. The aminothiazole ring makes an angle of 14.53 (13) with the ferrocenyl ring to which it is attached. In the crystal, pairs of complex molecules interact via intermolecular N-HÁ Á ÁN hydrogen bonds, forming a cyclic dimer which then interacts with other dimers through C-HÁ Á Á interactions.

Chemical context
Recently, the synthesis of new hybrid compounds based on a ferrocenyl group linked to a five-membered heterocyclic unit has drawn attention (Sá nchez- Rodríguez et al., 2017;Shao et al., 2006a). One important five-membered heterocycle is 2-aminothiazole, which is a versatile scaffold extensively used in various branches of chemistry including dyes and in the pharmaceutical industries. 2-Aminothiazole derivatives are widely used by medicinal chemists (Das et al., 2016) and have various applications in medicinal, agriculture and analytical chemistry. They are known to exhibit a wide variety of biological activities such as antiviral, antibacterial, antifungal, antitubercular, herbicidal and insecticidal (Mishra et al., 2017;Ji Ram et al., 2019;Dondoni, 2010). Thiazoles are also used as precursors or intermediates for the synthesis of a variety of heterocyclic compounds (Zeng et al., 2003). We report here the crystal and molecular structure of 2-amino-4-ferrocenylthiazole, which has not previously been reported.

Structural commentary
The title compound crystallizes in the monoclinic system, space group P2 1 /c. The asymmetric unit contains one molecular unit as shown in Fig. 1. The C15-S11-C12 bond angle of 88.6 (2) reflects the presence of a non-delocalized lone pair of electrons and is similar to that observed in other thiazoles. The length of the C12 N13 double bond is 1.306 (4) Å . The torsion angles in the amino substituted thiazole ring are: 1.1 (3) for N13-C12-S11-C15 and 1.7 (4) for N13-C14-C15-S11. All bond lengths and angles confirm the sp 2 hybridization for all C and N atoms.

Database survey
Cg1 is the centroid of the C1-C5 Cp ring.

Figure 2
The packing of the title compound. The dotted lines indicate intermolecular hydrogen bonds. All H atoms not involved in these interactions have been omitted for clarity.  Shao et al., 2006b;QAYSAL01, Shao et al., 2006a;RAPQAB, Shao et al., 2005;RAPQAB01, Shao et al., 2006a), the thiazole ring is substituted. In two cases there is no substitution in the thiazole ring (GUPKAG, Xu et al., 2020 andPAWWEQ, Plazuk et al., 2005) with PAWWEQ being a diferrocenyl compound. In all eight cases, the bond lengths and angles confirm the sp 2 hybridization for all C and N atoms.

Refinement details
Crystal data, data collection and structure refinement details are summarized in Table 2. N-bound H atoms were refined isotropically with U iso (H) = 1.2U eq (N). C-bound H atoms were positioned geometrically (C-H = 0.93-0.98 Å ) and refined with isotropically U iso (H) = 1.2U eq (C) using a riding model.

Funding information
We thank the DGAPA (project IN209020) for financial support.

Computing details
Data collection: APEX2 (Bruker, 2014); cell refinement: APEX2 (Bruker, 2014); data reduction: SAINT (Bruker, 2014); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL (Sheldrick, 2015b); molecular graphics: XP (Siemens, 1998); software used to prepare material for publication: CIFTAB (Sheldrick, 2013). 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.