Synthesis and structure of 1-{(E)-[(6-meth­oxy­pyridin-2-yl)methyl­idene]amino}-3-phenyl­thio­urea

Muthirakalayil Abraham, L.; Arunkumar, A.; Velusamy, M.; Chinnathangavel, T.; Rajendiran, V.

doi:10.1107/S2056989026004111

research communications

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ISSN: 2056-9890

Volume 82| Part 6| June 2026| Pages 674-677

https://doi.org/10.1107/S2056989026004111

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Synthesis and structure of 1-{(E)-[(6-methoxypyridin-2-yl)methylidene]amino}-3-phenylthiourea

Liji Muthirakalayil Abraham,^a Amirthalingam Arunkumar,^a Marappan Velusamy,^b Thangaraja Chinnathangavel ^c and Venugopal Rajendiran ^a ^*

^aDepartment of Chemistry, School of Basic and Applied Sciences, Central University of Tamil Nadu, Thiruvarur 610 005, India, ^bDepartment of Chemistry, North Eastern Hill University, Shillong 793022, India, and ^cDepartment of Chemistry, Anna University Regional Campus, Madurai 625019, India
^*Correspondence e-mail: [email protected]

Edited by W. T. A. Harrison, University of Aberdeen, United Kingdom (Received 31 March 2026; accepted 19 April 2026; online 15 May 2026)

The title compound, C₁₄H₁₄N₄OS, was crystallized at −20 °C by ether diffusion into an ethanol solution. The dihedral angle between the planes of the aromatic rings is 38.19 (19)° and the molecular conformation is supported by two intramolecular N—H⋯N hydrogen bonds. In the extended structure, N—H⋯O hydrogen bonds link the molecules into [011] chains. Hirshfeld surface analysis shows that H⋯H (44%), C⋯H/H⋯C (25%) and S⋯H/H⋯S (11.4%) contacts contibute the largest amounts.

Keywords: Schiff base; thiosemicarbazone; crystal structure; Hirshfeld surface analysis.

CCDC reference: 2535197

1. Chemical context

Thiosemicarbazones, containing an –NH–(C=S)–NH=N– unit, are widely studied members of the Schiff base family: numerous articles discuss various synthetic strategies to prepare them and their applications, including optical devices, dyes, pharmaceuticals, biological activity, nanotechnology and catalytic activity (e.g. Nidhi et al., 2025 ; Kumar et al., 2022 ; Shahzad Munawar et al., 2018 ). The addition of a pyridin-2-yl moiety to these thiosemicarbazide frameworks can make them more effective in biological applications, such as anticancer, antimicrobial, antifungal, antiviral and antibacterial activities (Zaware et al., 2025 ).

Triapine (3-aminopyridine-2-carboxaldehyde thiosemicarbazone; C₇H₉N₅S), an α-N-pyridylthiosemicarbazone, is a potent ribonucleotide reductase (RR) inhibitor currently undergoing clinical trials (Finch et al., 1999 ), which is believed to function by chelating iron ions. COTI-2 is a third-generation thiosemicarbazone that has received FDA (US Food and Drug Administration) orphan drug designation for ovarian cancer. It is undergoing phase 1 clinical trials (Lindemann et al., 2019 ). Several metal–Schiff base complexes are being studied for their various biological activities (Bajaj et al., 2021 ; Pervaiz et al., 2024 ; Jiang et al., 2024 ; Karpagam et al., 2022 ).

As part of our work in this area, we now describe the synthesis, structure and Hirshfeld surface of the title thiosemicarbazone, 1-{(E)-[(6-methoxypyridin-2-yl)methylidene]amino}-3-phenylthiourea (I), formed from the condensation reaction of 6-methoxypyridine-2-carboxaldehyde and 4-phenyl thiosemicarbazide.

2. Structural commentary

Compound (I) consists of an o-substituted pyridyl–Schiff base moiety connected to the phenyl-substituted thiosemicarbazide unit through an azomethine bond. It crystallizes in the orthorhombic space group Pna2₁, with one molecule in the asymmetric unit, as illustrated in Fig. 1. The compound contains three main structural fragments, a methoxy-substituted pyridine ring, an imine linkage and a phenylthiosemicarbazide group. The imine bond, with a C7=N2 bond length of 1.287 (5) Å, adopts the expected E configuration for the carbon–nitrogen bond, where the pyridyl ring is placed trans to the thiosemicarbazide N atom. The central chain adopts an extended conformation that allows partial electronic delocalization across the pyridine—C=N—N—C(=S)—NH—phenyl framework, as discussed previously for aryl-containing thiosemicarbazones (Palenik et al., 1974 ). The N3—N2 bond length in the thiosemicarbazide part is 1.360 (4) Å, which is shorter than the expected N—N single bond length (1.45 Å). Also, the C6—C7 bond length is 1.461 (5) Å, which is shorter than the usual C—C single bond length (1.54 Å), which suggests a partial double-bond character due to the conjugation with the imine group (Bhatia et al., 1977 ). Conversely, the thiocarbonyl bond, represented by C8—S1, shows a bond length of 1.658 (4) Å, which is longer than a typical C=S double bond length (1.56 Å), but much shorter than a typical C—S single bond length of 1.82 Å: this also confirms the extensive conjugation within the system.

Figure 1
The molecular structure of (I), with displacement ellipsoids drawn at the 50% probability level. Intramolecular N—H⋯N hydrogen bonds are shown as red dashed lines.

The dihedral angle between the C2–C6/N1 and C9–C14 aromatic rings is 38.19 (19)°. The C atom of the methoxy group attached to the ortho position of the pyridine ring is approximately coplanar with the aromatic ring [displacement = 0.080 (6) Å] and the N1—C2—O1 and C3—C2—O1 bond angles are 118.5 (3) and 117.1 (3)°, respectively. The C2(aryl)—O1 bond length is 1.353 (4) Å, whereas the O1—C1(methyl) bond length is 1.429 (5) Å: this difference is typical for methoxy-substituted aromatic systems (Jones & Shaw, 1992 ). Two intramolecular N—H⋯N hydrogen bonds (Table 1) help to consolidate the molecular conformation: the N3—H3⋯N1 hydrogen bond closes an S(6) ring and the N4—H4⋯N2 hydrogen bond an S(5) ring. A short C—H⋯S contact is also present.

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N3—H3⋯N1	0.89 (3)	1.99 (4)	2.662 (4)	131 (3)
N4—H4⋯N2	0.91 (4)	2.07 (5)	2.576 (5)	114 (4)
N4—H4⋯O1ⁱ	0.91 (4)	2.38 (5)	3.230 (4)	155 (3)
C14—H14⋯S1	0.97 (3)	2.78 (3)	3.249 (5)	110 (2)
Symmetry code: (i) $[-x+{\script{1\over 2}}, y+{\script{1\over 2}}, z-{\script{1\over 2}}]$ .

3. Supramolecular features

In the extended structure, N4—H4⋯O1 hydrogen bonds link the molecules into C(10) [01 $[\overline{1}]$ ] chains (Fig. 2). This N—H group also forms an intramolecular hydrogen bond (see above) and the bond-angle sum at the H atom is 357°.

Figure 2
The packing diagram of (I), with intramolecular N—H⋯N hydrogen bonds shown as red dashed lines and intermolecular N—H⋯O hydrogen bonds shown as blue dashed lines.

4. Hirshfeld surface analysis

The Hirshfeld surface analysis of (I) was performed using CrystalExplorer (Version 21.5; Spackman et al., 2021 ) and the d_norm map is illustrated in Fig. 3, with the intense red spots corresponding to the donor and acceptor groups for the N—H⋯O hydrogen bond. Two-dimensional fingerprint plots are shown in Fig. 4. Interactions between the H atoms (H⋯H) show the largest contribution (∼44%) to the Hirshfeld surface, with a distance range of d_e + d_i ≃ 2.5 Å. Nearly 25% is contributed by C⋯H/H⋯C interactions. Similarly, 11.4, 6.2, 5.4, 4.7 and 1.4% of the interactions are contributed by S⋯H/H⋯S, N⋯H/H⋯N, O⋯H/H⋯O, C⋯N/N⋯C and S⋯C/C⋯S interactions, respectively. Finally, C⋯C, N⋯O/O⋯N and S⋯N/N⋯S interactions each contribute less than 1% to the contact surface.

Figure 3
Hirshfeld surfaces of (I) mapped over (A) d_norm, (B) d_i and (C) d_norm (transparent Hirshfeld surface).

Figure 4
Two-dimensional fingerprint plots for (I): (a) all interactions; (b) H⋯H; (c) C⋯H/H⋯C; (d) S⋯H/H⋯S; (e) N⋯H/H⋯N; (f) O⋯H/H⋯O.

5. Database survey

Several thiosemicarbazones have been reported in the literature, but only two structures have a 6-substituted pyridine moiety, viz. 6-methylpyridine-2-carbaldehyde-N(4)-phenylthiosemicarbazone and 6-bromo-2-formylpyridine-N(4)-phenylthiosemicarbazone (CSD refcodes BAFGAS and BAFGEW, respectively; Chumakov et al., 2011 ).

6. Synthesis and crystallization

To 15 ml of a hot ethanolic solution of 6-methoxypyridine-2-carboxaldehyde (0.137 g, 1.00 mmol) with two added drops of glacial acetic acid, 4-phenylthiosemicarbazide (0.167 g, 1.00 mmol) dissolved in ethanol was added dropwise, and the mixture was refluxed for 2 h, which, on cooling to room temperature, gave a yellow precipitate. The obtained product was then recrystallised from ethanol solution by ether diffusion at −20 °C to give yellow needles of the title compound (yield 72%).

7. Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2.

Table 2
Experimental details

Crystal data
Chemical formula	C₁₄H₁₄N₄OS
M_r	286.35
Crystal system, space group	Orthorhombic, Pna2₁
Temperature (K)	296
a, b, c (Å)	17.811 (4), 5.2400 (14), 15.340 (4)
V (Å³)	1431.7 (6)
Z	4
Radiation type	Mo Kα
μ (mm⁻¹)	0.23
Crystal size (mm)	0.42 × 0.37 × 0.26

Data collection
Diffractometer	Bruker
No. of measured, independent and observed [I > 2σ(I)] reflections	23242, 3409, 2258
R_int	0.078
(sin θ/λ)_max (Å⁻¹)	0.660

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.040, 0.096, 1.02
No. of reflections	3409
No. of parameters	238
No. of restraints	1
H-atom treatment	All H-atom parameters refined
Δρ_max, Δρ_min (e Å⁻³)	0.17, −0.16
Absolute structure	Flack x determined using 859 quotients [(I⁺−(I⁻)]/[(I⁺)+(I⁻)] (Parsons et al., 2013 )
Absolute structure parameter	−0.04 (6)
Computer programs: APEX3 and SAINT (Bruker, 2018 ), SHELXT2014 (Sheldrick, 2015a ), SHELXL2018 (Sheldrick, 2015b ), Mercury (Macrae et al., 2020 ) and publCIF (Westrip, 2010 ).

Supporting information

CCDC reference: 2535197

Crystal structure: contains datablock I. DOI: https://doi.org/10.1107/S2056989026004111/hb8209sup1.cif

Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989026004111/hb8209Isup2.hkl

Supporting information file. DOI: https://doi.org/10.1107/S2056989026004111/hb8209Isup3.cml

checkCIF report

Computing details top

1-{(E)-[(6-Methoxypyridin-2-yl)methylidene]amino}-3-phenylthiourea top

Crystal data top

C₁₄H₁₄N₄OS	D_x = 1.328 Mg m⁻³
M_r = 286.35	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pna2₁	Cell parameters from 3409 reflections
a = 17.811 (4) Å	θ = 2.3–28.0°
b = 5.2400 (14) Å	µ = 0.23 mm⁻¹
c = 15.340 (4) Å	T = 296 K
V = 1431.7 (6) Å³	Needle, yellow
Z = 4	0.42 × 0.37 × 0.26 mm
F(000) = 600

Data collection top

Bruker diffractometer	R_int = 0.078
ω and phi scans	θ_max = 28.0°, θ_min = 2.3°
23242 measured reflections	h = −23→23
3409 independent reflections	k = −6→6
2258 reflections with I > 2σ(I)	l = −20→20

Refinement top

Refinement on F²	All H-atom parameters refined
Least-squares matrix: full	w = 1/[σ²(F_o²) + (0.0348P)² + 0.1169P] where P = (F_o² + 2F_c²)/3
R[F² > 2σ(F²)] = 0.040	(Δ/σ)_max < 0.001
wR(F²) = 0.096	Δρ_max = 0.17 e Å⁻³
S = 1.02	Δρ_min = −0.16 e Å⁻³
3409 reflections	Extinction correction: SHELXL2018 (Sheldrick, 2015b), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
238 parameters	Extinction coefficient: 0.030 (3)
1 restraint	Absolute structure: Flack x determined using 859 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons et al., 2013)
Primary atom site location: dual	Absolute structure parameter: −0.04 (6)
Hydrogen site location: difference Fourier map

Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
S1	0.40063 (6)	0.6279 (2)	0.58169 (8)	0.0694 (4)
N1	0.21315 (14)	0.0452 (5)	0.58787 (19)	0.0431 (6)
N3	0.29424 (17)	0.3856 (6)	0.4999 (2)	0.0479 (7)
O1	0.22148 (15)	−0.0365 (6)	0.73431 (15)	0.0662 (9)
N2	0.25657 (17)	0.3109 (7)	0.4272 (2)	0.0538 (8)
N4	0.36505 (17)	0.6321 (6)	0.4102 (2)	0.0483 (7)
C2	0.1914 (2)	−0.0897 (7)	0.6554 (2)	0.0486 (9)
C9	0.4233 (2)	0.7937 (7)	0.3791 (2)	0.0454 (8)
C8	0.3525 (2)	0.5529 (6)	0.4928 (2)	0.0463 (8)
C6	0.1817 (2)	−0.0119 (7)	0.5095 (2)	0.0439 (8)
C10	0.4548 (2)	0.7346 (8)	0.2986 (3)	0.0512 (9)
C11	0.5105 (2)	0.8881 (9)	0.2637 (3)	0.0585 (11)
C7	0.2064 (2)	0.1351 (8)	0.4338 (2)	0.0534 (9)
C3	0.1383 (2)	−0.2814 (9)	0.6519 (3)	0.0628 (11)
C14	0.4467 (2)	1.0090 (8)	0.4234 (3)	0.0547 (9)
C5	0.1280 (2)	−0.2000 (7)	0.5005 (3)	0.0531 (9)
C13	0.5027 (2)	1.1614 (8)	0.3869 (3)	0.0607 (11)
C12	0.5341 (3)	1.0994 (9)	0.3078 (3)	0.0654 (12)
C4	0.1065 (2)	−0.3363 (7)	0.5728 (4)	0.0621 (11)
C1	0.2800 (3)	0.1498 (13)	0.7369 (3)	0.0737 (14)
H10	0.441 (2)	0.584 (8)	0.269 (3)	0.067 (12)*
H4A	0.070 (2)	−0.481 (9)	0.568 (3)	0.085 (14)*
H13	0.515 (2)	1.312 (8)	0.418 (3)	0.066 (12)*
H14	0.423 (2)	1.057 (6)	0.478 (2)	0.047 (10)*
H3A	0.127 (2)	−0.373 (7)	0.698 (3)	0.059 (12)*
H5	0.105 (2)	−0.236 (8)	0.438 (3)	0.068 (12)*
H7	0.183 (2)	0.093 (7)	0.378 (3)	0.061 (11)*
H3	0.285 (2)	0.316 (7)	0.552 (2)	0.057 (11)*
H12	0.572 (3)	1.212 (8)	0.284 (3)	0.080 (13)*
H11	0.531 (3)	0.848 (8)	0.209 (4)	0.095 (17)*
H4	0.338 (3)	0.540 (7)	0.371 (3)	0.071 (13)*
H1A	0.321 (3)	0.107 (8)	0.687 (4)	0.096 (15)*
H1B	0.293 (3)	0.145 (8)	0.792 (3)	0.081 (15)*
H1C	0.258 (3)	0.319 (11)	0.722 (4)	0.096 (19)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
S1	0.0726 (7)	0.0868 (7)	0.0489 (5)	−0.0254 (6)	−0.0119 (6)	0.0070 (6)
N1	0.0374 (14)	0.0560 (16)	0.0357 (13)	−0.0022 (12)	−0.0006 (14)	0.0066 (15)
N3	0.0458 (19)	0.0634 (18)	0.0344 (15)	−0.0129 (14)	−0.0020 (13)	0.0081 (15)
O1	0.0607 (19)	0.097 (2)	0.0404 (14)	−0.0231 (16)	−0.0035 (13)	0.0160 (15)
N2	0.0535 (19)	0.073 (2)	0.0353 (16)	−0.0123 (17)	−0.0057 (14)	0.0069 (15)
N4	0.0474 (18)	0.0577 (19)	0.0397 (16)	−0.0103 (15)	−0.0020 (13)	0.0102 (15)
C2	0.042 (2)	0.061 (2)	0.042 (2)	−0.0033 (17)	0.0007 (17)	0.0089 (18)
C9	0.0398 (17)	0.045 (2)	0.051 (2)	0.0035 (16)	−0.0027 (16)	0.0145 (16)
C8	0.045 (2)	0.0474 (19)	0.0462 (19)	−0.0006 (17)	−0.0011 (16)	0.0043 (17)
C6	0.0400 (18)	0.049 (2)	0.0422 (18)	0.0011 (16)	−0.0021 (16)	−0.0016 (15)
C10	0.047 (2)	0.055 (2)	0.052 (2)	0.0010 (19)	0.0019 (18)	0.0135 (19)
C11	0.049 (2)	0.069 (3)	0.058 (2)	0.005 (2)	0.005 (2)	0.019 (2)
C7	0.056 (2)	0.067 (2)	0.0366 (18)	−0.010 (2)	−0.0080 (17)	0.0019 (18)
C3	0.056 (2)	0.070 (3)	0.062 (3)	−0.013 (2)	0.007 (2)	0.018 (2)
C14	0.054 (2)	0.046 (2)	0.064 (3)	0.0043 (18)	0.006 (2)	0.0062 (19)
C5	0.049 (2)	0.056 (2)	0.054 (2)	−0.0049 (19)	−0.0026 (18)	−0.003 (2)
C13	0.054 (2)	0.046 (2)	0.083 (3)	−0.0013 (19)	−0.009 (2)	0.012 (2)
C12	0.051 (3)	0.064 (3)	0.082 (3)	0.002 (2)	0.001 (2)	0.026 (3)
C4	0.053 (2)	0.060 (2)	0.073 (3)	−0.0134 (19)	−0.001 (2)	0.005 (2)
C1	0.068 (3)	0.108 (4)	0.045 (2)	−0.025 (3)	−0.015 (2)	0.013 (3)

Geometric parameters (Å, º) top

S1—C8	1.658 (4)	C10—H10	0.94 (4)
N1—C2	1.312 (4)	C11—C12	1.364 (6)
N1—C6	1.360 (4)	C11—H11	0.93 (5)
N3—N2	1.360 (4)	C7—H7	0.97 (4)
N3—C8	1.363 (4)	C3—C4	1.369 (7)
N3—H3	0.89 (4)	C3—H3A	0.88 (4)
O1—C2	1.354 (4)	C14—C13	1.396 (6)
O1—C1	1.429 (5)	C14—H14	0.98 (4)
N2—C7	1.287 (5)	C5—C4	1.374 (7)
N4—C8	1.352 (4)	C5—H5	1.07 (4)
N4—C9	1.422 (5)	C13—C12	1.374 (6)
N4—H4	0.91 (5)	C13—H13	0.95 (4)
C2—C3	1.381 (5)	C12—H12	0.97 (5)
C9—C14	1.382 (6)	C4—H4A	1.00 (5)
C9—C10	1.390 (5)	C1—H1A	1.09 (5)
C6—C5	1.381 (5)	C1—H1B	0.88 (5)
C6—C7	1.461 (5)	C1—H1C	1.00 (6)
C10—C11	1.386 (6)

C2—N1—C6	117.2 (3)	N2—C7—C6	130.5 (3)
N2—N3—C8	119.7 (3)	N2—C7—H7	113 (2)
N2—N3—H3	122 (2)	C6—C7—H7	116 (2)
C8—N3—H3	118 (2)	C4—C3—C2	118.0 (4)
C2—O1—C1	117.1 (3)	C4—C3—H3A	120 (3)
C7—N2—N3	118.9 (3)	C2—C3—H3A	121 (3)
C8—N4—C9	128.1 (3)	C9—C14—C13	119.0 (4)
C8—N4—H4	112 (3)	C9—C14—H14	120 (2)
C9—N4—H4	119 (3)	C13—C14—H14	121 (2)
N1—C2—O1	118.5 (3)	C4—C5—C6	118.9 (4)
N1—C2—C3	124.4 (4)	C4—C5—H5	122 (2)
O1—C2—C3	117.1 (3)	C6—C5—H5	119 (2)
C14—C9—C10	119.8 (4)	C12—C13—C14	120.7 (4)
C14—C9—N4	122.7 (4)	C12—C13—H13	124 (3)
C10—C9—N4	117.3 (3)	C14—C13—H13	116 (3)
N4—C8—N3	113.5 (3)	C11—C12—C13	120.3 (4)
N4—C8—S1	127.8 (3)	C11—C12—H12	121 (3)
N3—C8—S1	118.7 (3)	C13—C12—H12	118 (3)
N1—C6—C5	122.1 (3)	C3—C4—C5	119.4 (4)
N1—C6—C7	117.5 (3)	C3—C4—H4A	120 (3)
C5—C6—C7	120.4 (4)	C5—C4—H4A	121 (3)
C11—C10—C9	120.2 (4)	O1—C1—H1A	109 (3)
C11—C10—H10	119 (3)	O1—C1—H1B	102 (3)
C9—C10—H10	121 (3)	H1A—C1—H1B	119 (4)
C12—C11—C10	120.0 (4)	O1—C1—H1C	108 (3)
C12—C11—H11	120 (3)	H1A—C1—H1C	107 (4)
C10—C11—H11	120 (3)	H1B—C1—H1C	111 (5)

C8—N3—N2—C7	173.5 (4)	C9—C10—C11—C12	−0.7 (6)
C6—N1—C2—O1	−179.8 (3)	N3—N2—C7—C6	−1.3 (7)
C6—N1—C2—C3	−1.1 (5)	N1—C6—C7—N2	2.7 (7)
C1—O1—C2—N1	−5.3 (6)	C5—C6—C7—N2	−177.7 (4)
C1—O1—C2—C3	175.9 (4)	N1—C2—C3—C4	0.6 (6)
C8—N4—C9—C14	−41.6 (6)	O1—C2—C3—C4	179.3 (4)
C8—N4—C9—C10	141.5 (4)	C10—C9—C14—C13	−1.1 (5)
C9—N4—C8—N3	−176.2 (3)	N4—C9—C14—C13	−178.0 (3)
C9—N4—C8—S1	1.6 (6)	N1—C6—C5—C4	−1.0 (6)
N2—N3—C8—N4	1.5 (5)	C7—C6—C5—C4	179.4 (3)
N2—N3—C8—S1	−176.5 (3)	C9—C14—C13—C12	0.3 (6)
C2—N1—C6—C5	1.3 (5)	C10—C11—C12—C13	−0.2 (6)
C2—N1—C6—C7	−179.2 (3)	C14—C13—C12—C11	0.4 (6)
C14—C9—C10—C11	1.3 (5)	C2—C3—C4—C5	−0.3 (6)
N4—C9—C10—C11	178.4 (3)	C6—C5—C4—C3	0.5 (6)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N3—H3···N1	0.89 (3)	1.99 (4)	2.662 (4)	131 (3)
N4—H4···N2	0.91 (4)	2.07 (5)	2.576 (5)	114 (4)
N4—H4···O1ⁱ	0.91 (4)	2.38 (5)	3.230 (4)	155 (3)
C14—H14···S1	0.97 (3)	2.78 (3)	3.249 (5)	110 (2)

Symmetry code: (i) −x+1/2, y+1/2, z−1/2.

Acknowledgements

We thank Dr Marrappan Velusamy at the Department of Chemistry, North Eastern Hill University, Shillong 793022, India, for collecting the crystal data.

Funding information

Funding for this research was provided by: Department of Biotechnology, Ministry of Science and Technology, India (grant No. BT/PR36476/NNT/28/1723/2020 to Venugopal Rajendiran); Department of Science and Technology, Ministry of Science and Technology, India (grant No. SR/FST/CS-1/2021/215).

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