( E )- N’ -(1-(Benzofuran-2-yl)ethylidene)-1-(4-Methoxyphenyl)-5- Methyl-1 H -1,2,3-Triazole-4-Carbohydrazide

: The reaction of equimolar equivalents of 1-(4-methoxyphenyl)-5-methyl-1 H -1,2,3-triazole-4-carbohydrazide ( 1 ) and 2-acetylbenzofuran ( 2 ) in anhydrous ethanol containing a catalytic amount of concentrated hydrochloric acid under reﬂux for 2 h gave ( E )- N ’-(1-(benzofuran-2-yl)ethylidene)-1- (4-methoxyphenyl)-5-methyl-1 H -1,2,3-triazole-4-carbohydrazide ( 3 ) in 86% yield. The structure of the title heterocycle 3 was conﬁrmed using nuclear magnetic resonance and X-ray diffraction.

Heterocycles play a central role in drug design with many medications containing heterocyclic fragments.Heterocycles can be used to manipulate drug properties, including polarity, lipophilicity, and hydrogen bonding capacity.Therefore, the pharmacological effectiveness of drugs can be optimized by modifying their heterocyclic moieties and substituents [7][8][9].Heterocycles containing the 1,2,3-triazole moiety act as active ingredients in a variety of medications, including antibiotics (e.g., cefatrizine and tazobactam) [10].In addition, benzofurans bearing various substituents at the C-2 position are commonly distributed in nature.They have a range of biological activities and can be used for the treatment of cardiac arrhythmias amongst other ailments [11][12][13].An example is ailanthoidol, a natural product containing benzofuran, which shows antiviral, antioxidant, and antifungal activities [14].
The current work reports the combination of benzofuran and 1,2,3-triazole moieties in a one-step reaction using a simple procedure to synthesize a novel hydrazone.Recently, the synthesis and structure elucidation of other new heterocycles have been reported [15,16].

Synthesis
The

IR and NMR Spectroscopy
The IR spectrum of 3 showed a strong absorption band at 1689 cm −1 due to the C=O group.The 1 H NMR spectrum of 3 showed the methoxy protons as a singlet signal at 3.82 ppm and two different methyl groups (2.42 and 2.51 ppm).In addition, the spectrum showed the presence of an exchangeable singlet signal that appeared at 10.71 ppm, due to the NH proton, along with nine aromatic protons.The 13 C NMR spectrum of 3 showed that the C4 of the 4-methoxylphenyl group was at a very low field (165.5 ppm).The C=O and C=N-NH carbons appeared at 162.4 and 160.0 ppm, respectively, whereas the carbon of the methoxy group appeared at a high field (60.9 ppm).See Supplementary Materials for details.

IR and NMR Spectroscopy
The IR spectrum of 3 showed a strong absorption band at 1689 cm −1 due to the C=O group.The 1 H NMR spectrum of 3 showed the methoxy protons as a singlet signal at 3.82 ppm and two different methyl groups (2.42 and 2.51 ppm).In addition, the spectrum showed the presence of an exchangeable singlet signal that appeared at 10.71 ppm, due to the NH proton, along with nine aromatic protons.The 13 C NMR spectrum of 3 showed that the C4 of the 4-methoxylphenyl group was at a very low field (165.5 ppm).The C=O and C=N-NH carbons appeared at 162.4 and 160.0 ppm, respectively, whereas the carbon of the methoxy group appeared at a high field (60.9 ppm).See Supplementary Materials for details.

IR and NMR Spectroscopy
The IR spectrum of 3 showed a strong absorption band at 1689 cm −1 due to the C=O group.The 1 H NMR spectrum of 3 showed the methoxy protons as a singlet signal at 3.8 ppm and two different methyl groups (2.42 and 2.51 ppm).In addition, the spectrum showed the presence of an exchangeable singlet signal that appeared at 10.71 ppm, due t the NH proton, along with nine aromatic protons.The 13 C NMR spectrum of 3 showed that the C4 of the 4-methoxylphenyl group was at a very low field (165.5 ppm).The C=O and C=N-NH carbons appeared at 162.4 and 160.0 ppm, respectively, whereas the carbon of the methoxy group appeared at a high field (60.9 ppm).See Supplementary Material for details.

Crystal Structure of 3
The molecule of 3 from the crystal structure is shown in Figure 1.The molecule com prises methoxybenzene (A: C1-C7, O1), methyltriazole (B: C8-C10, N1-N3), N-ethyli deneformohydrazide (C: C11-C13, O2, N4, N5), and benzofuran (D: C14-C21, O3) moie ties.In the crystal, the molecules are arranged in layers that are oriented parallel to the ab plane (Figure 2a).Within a layer, interactions of the π-π type occur between the benzofuran and triazole rings of neighboring pairs of molecules, with centroid-to-centroid distances of 3.679 Å between the two groups (Figure 2b).The B-D planes of molecules within one layer are parallel.In contrast, the planes in neighboring layers are roughly perpendicular to each other, being oriented parallel to either (110) and (−110). (7).
In the crystal, the molecules are arranged in layers that are oriented parallel to the ab plane (Figure 2a).Within a layer, interactions of the - type occur between the benzofuran and triazole rings of neighboring pairs of molecules, with centroid-to-centroid distances of 3.679 Å between the two groups (Figure 2b).The B-D planes of molecules within one layer are parallel.In contrast, the planes in neighboring layers are roughly perpendicular to each other, being oriented parallel to either (110) and (−110).

General
Chemicals and solvents were obtained from Merck.The IR spectrum of 3 was recorded on a Bruker Vertex 80 ATR-FTIR spectrometer (400-4000 cm −1 ).The NMR spectra (500 MHz for 1 H and 125 MHz for 13 C) of 3 were obtained using a JEOLNMR spectrometer.The chemical shift (δ) is reported in ppm and coupling constant (J) was measured in Hz.The NMR spectra were recorded in DMSO-d 6 .Procedures from the literature were used to prepare both 1 [17] and 2 [18].

Synthesis of 3
A mixture of 1 (0.49 g, 2.0 mmol) and 2 (0.32 g, 2.0 mmol) in dry EtOH (15 mL) containing concentrated HCl (0.1 mL) was refluxed for 2 h.The mixture was left to cool to

Crystal Structure Determination
An Agilent SuperNova Dual Atlas diffractometer using mirror monochromated MoKα radiation was used to collect single-crystal diffraction data.The structure was solved with direct methods using SHELXS [19] and refined using full-matrix least-squares methods on F 2 with SHELXL [20].

Conclusions
A new heterocycle containing 1,2,3-triazole and benzofuran moieties was synthesized with excellent yield using a simple procedure.The structure of the title heterocycle was established using X-ray diffraction and nuclear magnetic resonance spectroscopy.

Supplementary Materials:
The following are available online.IR, 1 H, and 13

Figure 1 .Scheme 1 .
Figure 1.An ortep representation of the molecule of 3 showing atomic displacement parameters with ellipsoids displayed at 50% probability.

Figure 1 .
Figure 1.An ortep representation of the molecule of 3 showing atomic displacement parameter with ellipsoids displayed at 50% probability.

Figure 1 .
Figure 1.An ortep representation of the molecule of 3 showing atomic displacement parameters with ellipsoids displayed at 50% probability.In the crystal structure, groups B-D of the molecule are essentially coplanar.The twist angles of the planes through groups B-D are 7.40 (12) • and 2.21 (10) • for B/C and C/D, respectively, illustrating the co-planarity.In contrast, the plane of the methoxybenzene group (A) deviates from the plane of B-D. as indicated by an A/B twist angle of 53.94 (7) • .In the crystal, the molecules are arranged in layers that are oriented parallel to the ab plane (Figure2a).Within a layer, interactions of the π-π type occur between the benzofuran and triazole rings of neighboring pairs of molecules, with centroid-to-centroid distances of 3.679 Å between the two groups (Figure2b).The B-D planes of molecules within one layer are parallel.In contrast, the planes in neighboring layers are roughly perpendicular to each other, being oriented parallel to either (110) and (−110).

Figure 2 .
Figure 2. (a) The crystal structure of 3 viewed down the a axis.(b) A segment of the crystal structure showing a layer with π-π interaction shown as green dashed lines.The atom colors are: grey = carbon, red = oxygen, blue = nitrogen, white = hydrogen.