(E)-1-[1-(6-Bromo-2-oxo-2H-chromen-3-yl)ethyl­idene]thio­semicarbazide

The title compound, C₁₂H₁₀BrN₃O₂S, exists in an E configuration with respect to the C=N bond. The approximately planar 2H-chromene ring system [maximum deviation = 0.059 (1) Å] is inclined at a dihedral angle of 17.50 (5)° with respect to the mean plane through the thio­semicarbazide unit and an intra­molecular N—H...N hydrogen bond generates an S(5) ring. In the crystal structure, adjacent mol­ecules are linked by N—H...S hydrogen bonds, forming [010] chains built up from R₂²(8) loops, such that each S atom accepts two such bonds. These chains are further inter­connected into sheets parallel to the ab plane via short Br...O inter­actions [3.0732 (13) Å] and a π–π aromatic stacking inter­action [3.7870 (8) Å] is also observed.

Key indicators

• Single-crystal X-ray study
• T = 100 K
• Mean [sigma](C-C) = 0.002 Å
• R factor = 0.021
• wR factor = 0.084
• Data-to-parameter ratio = 27.2

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT250_ALERT_2_C Large U3/U1 Ratio for Average U(i,j) Tensor ....       2.38
PLAT352_ALERT_3_C Short   N-H Bond (0.87A)   N2     -   H1N2   ...       0.73 Ang.
PLAT431_ALERT_2_C Short Inter HL..A Contact  Br1    ..  O2      ..       3.07 Ang.
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.600         36
PLAT913_ALERT_3_C Missing # of Very Strong Reflections in FCF ....          1
PLAT912_ALERT_4_C Missing # of FCF Reflections Above STh/L=  0.600         22

Alert level G
PLAT960_ALERT_3_G Number of Intensities with I .LT. - 2*sig(I) ..           2
PLAT063_ALERT_4_G Crystal Size Likely too Large for Beam Size ....       0.73 mm
PLAT154_ALERT_1_G The su's on the Cell Angles are Equal  (x 10000)        200 Deg.
PLAT720_ALERT_4_G Number of Unusual/Non-Standard Labels ..........          3

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   6 ALERT level C = Check and explain
   4 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   2 ALERT type 2 Indicator that the structure model may be wrong or deficient
   4 ALERT type 3 Indicator that the structure quality may be low
   3 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

Thiosemicarbazide compounds exhibit various biological activities such as anti-bacterial, anti-fungal and especially anti-tuberculosis (Shukla et al., 1984, Desai et al., 1984). Apart from this, coumarins constitute an important class of compounds found throughout the plant kingdom and are known to have diverse activities such as anti-coagulants (Anderson et al., 2002, Tassies et al., 2002), anti-bacterial (Mitscher, 2002, Laffitte et al., 2002), anti-fungal (Moffett, 1964) and cytotoxicity (Weber et al., 1998) properties. The coumarin moiety and related derivatives are also reported to have importance as vasodilators (Hoult & Payá, 1996), anti-mutagenic agents (Pillai et al., 1999), scavengers of reactive oxygen species (Finn et al., 2004), as well as lipoxygenese and cyclooxygenese inhibitors (Kimura et al., 1985, Hofmanová et al., 1998). The title compound exhibits very good anti-bacterial activity against Escherichia coli and Bacillus. subtilus (Chulian et al., 2009). The objective of this study is to synthesize new derivatives of coumarin-thiosemicarbazide compounds. We present in this paper the crystal structure of this title compound.

The title thiosemicarbazide compound (Fig. 1) exists in a cis configuration with respect to the Schiff base C10═N1 bond [N1═C10 = 1.2890 (15) Å; torsion angle C9–C10–N1–N2 = 178.83 (10)°]. The 2H-chromene ring system (C1-C9/O1) is approximately planar, with a maximum deviation of 0.059 (1) Å at atom C9. The mean plane through the thiosemicarbazide moiety (N1/N2/C11/N3/S1) forms dihedral angle of 17.50 (5)° with the 2H-chromene ring system. Bond lengths and angles are consistent to a closely related structure (Arshad et al., 2010).

In the crystal structure, pairs of intermolecular N2—H1N2···S1 and N3—H1N3···S1 hydrogen bonds (Table 1) form bifurcated acceptor hydrogen bonds which generate two different R²₂(8) hydrogen bond ring motifs with zig-zag formation (Fig. 2, Bernstein et al., 1995). These hydrogen bonds link adjacent molecules into two-molecule wide chains along the b axis. Intermolecular short Br···O interactions [Br1···O2ⁱⁱⁱ = 3.0732 (13) Å; (iii) x+1, y-1, z] interconnect these chains into two-dimensional planes parallel to the ab plane (Fig. 3). The crystal structure is further stabilized by weak Cg1···Cg1 interactions involving the centroid of the C2-C7 benzene ring [Cg1···Cg1^iv = 3.7870 (8) Å; (iv) -x+1, -y, -z].

Related literature

For general background to and applications of the title thiosemicarbazide compound, see: Anderson et al. (2002); Chulian et al. (2009); Desai et al. (1984); Finn et al. (2004); Hofmanová et al. (1998); Hoult et al. (1996); Kimura et al. (1985); Laffitte et al. (2002); Mitscher (2002); Moffett (1964); Pillai et al. (1999); Shukla et al. (1984); Tassies et al. (2002); Weber et al. (1998). For the preparation, see: Moamen et al. (2009). For graph-set descriptions of hydrogen-bond ring motifs, see: Bernstein et al. (1995). For a related structure, see: Arshad et al. (2010). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986).

S2. Experimental

Coumarin thiosemicarbazone was prepared by cyclocondensation of 5-bromosalicylaldehyde with ethylacetoacetate and the resulting acetyl coumarin intermediate was then treated with thiosemicarbazide to get the title compound as reported in the literature with some modifications (Moamen et al., 2009). The methanol solution of thiosemicarbazide (5.00 mmol) was added to a solution of 6-bromo-(3-acethylcoumarin) (5.00 mmol) in hot methanol (10 ml) while stirring. The resulting solution was refluxed for 1 h and then pH of the solution was adjusted to 4–5 by adding glacial acetic acid. The solution was again refluxed for 4 h. The title compound was recrystallized from ethyl acetate:ethanol (2:1) to give yellow needles of (I).

S3. Refinement

H atoms bound to N atoms were located from difference Fourier map and allowed to refine freely [range of N—H = 0.73 (3)–0.82 (3) Å]. All other H atoms were placed in their calculated positions, with C—H = 0.93 or 0.96 Å, and refined using a riding model, with U_iso = 1.2 or 1.5 U_eq(C). A rotating group model was used for the C12 methyl group.

Computing details

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Figures

	Fig. 1. The molecular structure of (I), showing 50 % probability displacement ellipsoids for non-H atoms.
	Fig. 2. Part of the crystal structure of (I), showing molecules being linked into an infinite chain incorporating zig-zag shaped R^22(8) ring motifs along the b axis.
	Fig. 3. The crystal structure of (I), viewed along the b axis, showing a two-molecule-wide plane parallel to the ab plane. Hydrogen atoms not involved in intermolecular interactions (dashed lines) have been omitted for clarity.

(E)-1-[1-(6-Bromo-2-oxo-2H-chromen-3- yl)ethylidene]thiosemicarbazide

Crystal data

C12H10BrN3O2S	Z = 2
Mr = 340.20	F(000) = 340
Triclinic, P1	Dx = 1.739 Mg m^−3
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.3796 (6) Å	Cell parameters from 9969 reflections
b = 8.1260 (7) Å	θ = 2.7–35.1°
c = 13.3756 (12) Å	µ = 3.33 mm^−1
α = 106.697 (2)°	T = 100 K
β = 95.095 (2)°	Needle, yellow
γ = 98.925 (2)°	0.73 × 0.20 × 0.15 mm
V = 649.57 (10) Å^3

Data collection

Bruker APEXII DUO CCD diffractometer	5036 independent reflections
Radiation source: fine-focus sealed tube	4733 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.020
φ and ω scans	θmax = 33.5°, θmin = 1.6°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −9→9
Tmin = 0.196, Tmax = 0.637	k = −12→12
19355 measured reflections	l = −20→20

Refinement

Refinement on F^2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F^2 > 2σ(F^2)] = 0.021	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.084	H atoms treated by a mixture of independent and constrained refinement
S = 1.17	w = 1/[σ^2(Fo^2) + (0.0569P)^2 + 0.0443P] where P = (Fo^2 + 2Fc^2)/3
5036 reflections	(Δ/σ)max = 0.001
185 parameters	Δρmax = 0.73 e Å^−3
0 restraints	Δρmin = −0.56 e Å^−3

Special details

Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1)K.

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.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > 2sigma(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
Br1	0.831903 (19)	−0.130575 (15)	0.134917 (9)	0.01986 (5)
S1	−0.52737 (6)	0.26734 (4)	0.52668 (3)	0.02208 (7)
O1	0.39540 (15)	0.46915 (12)	0.12143 (7)	0.01830 (16)
O2	0.14155 (19)	0.62282 (15)	0.15561 (9)	0.0270 (2)
N1	−0.08889 (17)	0.33908 (13)	0.34997 (8)	0.01559 (17)
N2	−0.24110 (18)	0.37175 (14)	0.41584 (8)	0.01611 (17)
N3	−0.2610 (2)	0.08895 (15)	0.41915 (9)	0.0204 (2)
C1	0.2259 (2)	0.50976 (16)	0.17462 (10)	0.0177 (2)
C2	0.48940 (19)	0.32942 (15)	0.12434 (9)	0.01509 (18)
C3	0.6564 (2)	0.29964 (17)	0.06532 (10)	0.0179 (2)
H3A	0.7011	0.3720	0.0255	0.022*
C4	0.75479 (19)	0.15951 (17)	0.06722 (9)	0.0178 (2)
H4A	0.8675	0.1375	0.0288	0.021*
C5	0.68424 (19)	0.05161 (16)	0.12688 (9)	0.01630 (19)
C6	0.51529 (19)	0.07869 (15)	0.18374 (9)	0.01632 (19)
H6A	0.4670	0.0031	0.2210	0.020*
C7	0.41777 (18)	0.22285 (15)	0.18420 (9)	0.01446 (18)
C8	0.25545 (18)	0.27089 (15)	0.24813 (9)	0.01512 (18)
H8A	0.2113	0.2048	0.2915	0.018*
C9	0.16407 (18)	0.41112 (15)	0.24698 (9)	0.01454 (18)
C10	−0.00056 (18)	0.46198 (15)	0.31560 (9)	0.01494 (18)
C11	−0.33190 (19)	0.23856 (15)	0.44883 (9)	0.01633 (19)
C12	−0.0508 (2)	0.64307 (16)	0.34349 (10)	0.0196 (2)
H12A	−0.0674	0.6814	0.4167	0.029*
H12B	−0.1814	0.6417	0.3013	0.029*
H12C	0.0641	0.7218	0.3302	0.029*
H1N2	−0.308 (5)	0.438 (4)	0.420 (3)	0.060 (9)*
H1N3	−0.317 (3)	0.005 (3)	0.4346 (16)	0.019 (4)*
H2N3	−0.164 (5)	0.094 (4)	0.383 (3)	0.057 (9)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.02111 (7)	0.01997 (7)	0.02278 (7)	0.01169 (5)	0.00823 (5)	0.00757 (5)
S1	0.02734 (16)	0.01628 (13)	0.03123 (16)	0.01088 (11)	0.02016 (13)	0.01232 (11)
O1	0.0205 (4)	0.0197 (4)	0.0223 (4)	0.0104 (3)	0.0121 (3)	0.0121 (3)
O2	0.0334 (5)	0.0302 (5)	0.0330 (5)	0.0205 (4)	0.0192 (4)	0.0220 (4)
N1	0.0174 (4)	0.0165 (4)	0.0162 (4)	0.0071 (3)	0.0086 (3)	0.0062 (3)
N2	0.0191 (4)	0.0145 (4)	0.0197 (4)	0.0078 (3)	0.0116 (3)	0.0078 (3)
N3	0.0264 (5)	0.0157 (4)	0.0259 (5)	0.0104 (4)	0.0158 (4)	0.0099 (4)
C1	0.0197 (5)	0.0189 (5)	0.0199 (5)	0.0086 (4)	0.0097 (4)	0.0096 (4)
C2	0.0157 (4)	0.0162 (4)	0.0162 (4)	0.0063 (4)	0.0057 (3)	0.0066 (4)
C3	0.0181 (5)	0.0216 (5)	0.0186 (5)	0.0077 (4)	0.0089 (4)	0.0092 (4)
C4	0.0166 (5)	0.0219 (5)	0.0176 (5)	0.0078 (4)	0.0075 (4)	0.0063 (4)
C5	0.0164 (4)	0.0176 (5)	0.0172 (4)	0.0084 (4)	0.0054 (4)	0.0053 (4)
C6	0.0173 (5)	0.0163 (4)	0.0186 (5)	0.0071 (4)	0.0068 (4)	0.0069 (4)
C7	0.0154 (4)	0.0149 (4)	0.0154 (4)	0.0055 (3)	0.0058 (3)	0.0058 (3)
C8	0.0158 (4)	0.0155 (4)	0.0171 (4)	0.0060 (4)	0.0068 (4)	0.0069 (4)
C9	0.0158 (4)	0.0152 (4)	0.0156 (4)	0.0059 (3)	0.0068 (3)	0.0064 (3)
C10	0.0155 (4)	0.0155 (4)	0.0167 (4)	0.0061 (4)	0.0065 (4)	0.0065 (3)
C11	0.0198 (5)	0.0146 (4)	0.0184 (5)	0.0068 (4)	0.0090 (4)	0.0072 (4)
C12	0.0234 (5)	0.0159 (5)	0.0248 (5)	0.0092 (4)	0.0121 (4)	0.0090 (4)

Geometric parameters (Å, º)

Br1—C5	1.8965 (11)	C3—C4	1.3879 (17)
S1—C11	1.6957 (12)	C3—H3A	0.9300
O1—C2	1.3722 (14)	C4—C5	1.3969 (17)
O1—C1	1.3770 (14)	C4—H4A	0.9300
O2—C1	1.2091 (15)	C5—C6	1.3827 (16)
N1—C10	1.2890 (15)	C6—C7	1.4079 (15)
N1—N2	1.3738 (14)	C6—H6A	0.9300
N2—C11	1.3516 (15)	C7—C8	1.4307 (16)
N2—H1N2	0.73 (3)	C8—C9	1.3613 (15)
N3—C11	1.3288 (15)	C8—H8A	0.9300
N3—H1N3	0.81 (2)	C9—C10	1.4846 (16)
N3—H2N3	0.82 (3)	C10—C12	1.5033 (16)
C1—C9	1.4665 (16)	C12—H12A	0.9600
C2—C3	1.3917 (16)	C12—H12B	0.9600
C2—C7	1.3930 (15)	C12—H12C	0.9600
C2—O1—C1	122.75 (9)	C5—C6—H6A	120.6
C10—N1—N2	119.10 (10)	C7—C6—H6A	120.6
C11—N2—N1	117.19 (10)	C2—C7—C6	118.95 (10)
C11—N2—H1N2	111 (3)	C2—C7—C8	118.13 (10)
N1—N2—H1N2	128 (3)	C6—C7—C8	122.83 (10)
C11—N3—H1N3	119.9 (15)	C9—C8—C7	121.52 (10)
C11—N3—H2N3	112 (2)	C9—C8—H8A	119.2
H1N3—N3—H2N3	128 (3)	C7—C8—H8A	119.2
O2—C1—O1	116.08 (11)	C8—C9—C1	119.13 (10)
O2—C1—C9	126.61 (11)	C8—C9—C10	120.96 (10)
O1—C1—C9	117.31 (10)	C1—C9—C10	119.90 (10)
O1—C2—C3	117.34 (10)	N1—C10—C9	113.79 (10)
O1—C2—C7	120.50 (10)	N1—C10—C12	124.38 (10)
C3—C2—C7	122.16 (10)	C9—C10—C12	121.81 (10)
C4—C3—C2	118.48 (11)	N3—C11—N2	117.80 (11)
C4—C3—H3A	120.8	N3—C11—S1	122.45 (9)
C2—C3—H3A	120.8	N2—C11—S1	119.74 (9)
C3—C4—C5	119.89 (10)	C10—C12—H12A	109.5
C3—C4—H4A	120.1	C10—C12—H12B	109.5
C5—C4—H4A	120.1	H12A—C12—H12B	109.5
C6—C5—C4	121.73 (10)	C10—C12—H12C	109.5
C6—C5—Br1	119.11 (9)	H12A—C12—H12C	109.5
C4—C5—Br1	119.11 (9)	H12B—C12—H12C	109.5
C5—C6—C7	118.75 (10)
C10—N1—N2—C11	179.07 (11)	C5—C6—C7—C8	−174.14 (11)
C2—O1—C1—O2	−171.47 (12)	C2—C7—C8—C9	3.45 (17)
C2—O1—C1—C9	7.73 (18)	C6—C7—C8—C9	179.96 (12)
C1—O1—C2—C3	178.59 (11)	C7—C8—C9—C1	3.09 (18)
C1—O1—C2—C7	−1.23 (18)	C7—C8—C9—C10	−178.55 (11)
O1—C2—C3—C4	179.76 (11)	O2—C1—C9—C8	170.56 (14)
C7—C2—C3—C4	−0.43 (19)	O1—C1—C9—C8	−8.54 (18)
C2—C3—C4—C5	0.48 (19)	O2—C1—C9—C10	−7.8 (2)
C3—C4—C5—C6	0.93 (19)	O1—C1—C9—C10	173.08 (11)
C3—C4—C5—Br1	−176.32 (9)	N2—N1—C10—C9	178.83 (10)
C4—C5—C6—C7	−2.35 (18)	N2—N1—C10—C12	0.63 (18)
Br1—C5—C6—C7	174.90 (9)	C8—C9—C10—N1	−18.82 (16)
O1—C2—C7—C6	178.81 (11)	C1—C9—C10—N1	159.52 (11)
C3—C2—C7—C6	−0.99 (18)	C8—C9—C10—C12	159.43 (12)
O1—C2—C7—C8	−4.54 (17)	C1—C9—C10—C12	−22.22 (17)
C3—C2—C7—C8	175.65 (11)	N1—N2—C11—N3	2.93 (17)
C5—C6—C7—C2	2.34 (18)	N1—N2—C11—S1	−177.80 (9)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N3—H2N3···N1	0.82 (3)	2.15 (3)	2.6004 (17)	114 (3)
N2—H1N2···S1^i	0.73 (3)	2.70 (3)	3.4094 (13)	165 (3)
N3—H1N3···S1^ii	0.81 (2)	2.49 (2)	3.3010 (13)	175.6 (19)

Symmetry codes: (i) −x−1, −y+1, −z+1; (ii) −x−1, −y, −z+1.