Synthesis and Crystal Structure of 1-(3-fluorophenyl)-3-(3,4,5- Trimethoxybenzoyl)thiourea

The title thiourea was synthesized by reaction of 3,4,5-trimethoxybenzoyl isothiocyante with 3-fluoroaniline. The 3,4,5-trimethoxybenzoyl isothiocyante was produced in situ by reaction of 3,4,5-trimethoxybenzoyl chloride with ammonium thiocyanate in dry acetonitrile. The structure was confirmed by the spectroscopic, elemental analysis and single crystal X-ray diffraction data. It crystallizes in the monoclinic space group P2 1 /c with unit cell dimensions a = 13.

Synthesis of title thiourea was carried out in continuation of our interest in the synthesis of thioureas as intermediates towards synthesis of novel heterocycles and for the systematic study of their bioactivity and complexation behavior.In the IR spectrum absorptions were observed at 3350 cm -1 , 3280 cm -1 for free and associated NH, at 1638 cm -1 for carbonyl and at 1240 cm -1 for thiocarbonyl, at 1586 cm -1 for C=C and 1150 cm -1 for C-N stretchings respectively.The characteristic broad singlets at δ 9.17 and 4.61 for HN (1) and HN(3), were observed in 1 HNMR.The carbonyl and thiocarbonyl peaks were observed at  176.3 and 178.2 respectively, in 13 CNMR.In the mass spectrum the molecular ion peaks and base peak derived from aroyl group were observed.

Crystal Structure Determination
Bond lengths and angles of the title compound are in the usual ranges.The dihedral angle between the two aromatic rings is 89.9°.Two of the three methoxy groups lie in the plane of the ring to which they are attached [torsion angles: C27-O2-C23-C22 0.12(19) o , C29-O4-C25-C26: 13.69(18)°], whereas the third one is twisted out of the ring plane [C28-O3-C24-C25 76.18( 15  The molecular structure of the title compound 1 along with the atom-numbering scheme is depicted in Figure 1.

Experimental Section
Melting points were recorded using a digital Gallenkamp (SANYO) model MPD BM 3.5 apparatus and are uncorrected. 1H NMR spectra were determined as CDCl 3 solutions at 300 MHz using a Bruker AM-300 spectrophotometer.FT IR spectra were recorded using an FTS 3000 MX spectrophotometer, Mass Spectra (EI, 70 eV) on a GC-MS instrument.All compounds were purified by thick layer chromatography using silica gel from Merck.

X-ray data collection and structure refinement
Crystallographic data were recorded on a STOE IPDS-II diffractometer [13] using Mo Kα radiation (λ = 0.71073 Å) at T = 173 K.An absorption correction was applied using the MULABS [14] option in PLATON [15].The structure was solved by direct methods [16] and refined by full-matrix least-squares using SHELXL-97 against F 2 using all data [16].All non-H atoms were refined anisotropically.H atoms were positioned geometrically at distances of 0.95 Å (aromatic CH) and 0.98 Å (methyl groups) from the parent C atoms; a riding model was used during the refinement process and the Uiso(H) values were constrained to be 1.2 Ueq(aromatic C) or 1.5 Ueq(methyl C).The H atoms bonded to N were freely refined.
Crystal data.

Conclusions
Synthesis, characterization and crystal structure of a novel thiourea derivative has been carried out which is an intermediate step towards a diversity of heterocyles.

Figure 1 .
Figure 1.Perspective view of the title compound.

Figure 2 .
Figure 2. A packing diagram of the title compound 1 with view onto the ab plane.H atoms bonded to C omitted for clarity.Hydrogen bonds drawn as dashed lines.