(Z)-Ethyl 2-cyano-3-(1-phenyl­ethyl­amino)but-2-enedithio­ate

The title mol­ecule, C₁₅H₁₈N₂S₂, adopts the Z configuration. The dihedral angle between the planes of the phenyl ring and the CH—NH—C=C(C[triple bond]N)—C(=S)—S fragment is 76.10 (5) Å. The mol­ecular structure is stabilized by a weak intra­molecular N—H...S hydrogen bond [H...S = 2.29 (3) Å, N...S = 2.981 (2) Å and N—H...S = 145 (2)°].

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.043
• wR factor = 0.122
• Data-to-parameter ratio = 17.1

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PLAT153_ALERT_1_C The su's on the Cell Axes are Equal (x 100000) .        300 Ang.
PLAT371_ALERT_2_C Long   C(sp2)-C(sp1) Bond  C2     -   C5     ...       1.44 Ang.

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PUBL024_ALERT_1_A The number of authors is greater than 5.
              Please specify the role of each of the co-authors
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Author Response: - Ms Toumi is researcher who does with work. Prof. K. Boujlel and Prof. M. Bordeau are resectively the director and codirector of thesis from the Unversity of Tunis El-Manar and the Unversity of Bordeaux I. Dr. Raouafi is the direct supervisor of Ms Toumi. Prof. Driss and Ms Ben Amor are the crystallographist who solve the strucutre.

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S1. Comment

Dithiocarboxylic acid and its derivatives are good complexing agents for transition metal elements (Contreras et al., 2004; Jansons, 1976). They exhibit antitumoral actvities (Hou et al., 2006), and are useful in isotope labelling methods with radioactive nuclei (Belhadj-Tahar et al., 1996). More recently, these compounds gained attention in polymer chemistry for their ability to control radical polymerization, especially the RAFT radical polymerization (Laus et al., 2001).

The electolysis of acetonitrile under galvanostatic conditions in the presence of tetrabutylammonium perchlorate as a supporting electrolyte gives the cyanomethyl anion, a strong base, enough to deprotonate primary, secondary amines and amino alcohols to give the corresponding anions, useful intermediates for mild synthesis of alkyl carbamates, and oxazolinones by reaction with carbon dioxide (Feroci et al., 2000; 2003).

Under these conditions, the electrolysis of 1-phenylethylamine followed by the addition of carbon disulfide and ethyliodide yields the title compound, (I). The product formation is a result of autocondensation of acetonitrile followed by removal of ammonia by nucleophilic substitution with 1-phenylethlyamine, finally reaction with CS₂ and EtI gives the compound (I). The structure of the N-unsbustituted compound (II) and its carboxylic analogue (III) have been reported (Szulzewsky et al., 1984). Compound (II) was obtained as a by-product during the course of reaction.

The structure determination of (I) was undertaken as a part of our studies on the generation and use of electrogenerated base (EGB) in organic synthesis and their applications in order to access to dithiocarbamates, dithiocarboxylic, trithiocarbonate esters (Toumi et al., 2007).

The molecular structure and labelling scheme are illustrated in Fig. 1. Atoms N1, N2, S1, S2, C1, C2, C3, C5 and C6 are coplanar, with an r.m.s deviation of 0.032 Å. The dihedral angle between the C8—C13 phenyl ring and the N1/N2/S1/S2/C1/C2/C3/C5/C6 plane is 76.10 (5) Å. The molecule adopts the Z configuration. The molecular structure is stabilized by an N2–H2···S1 intramolecular hydrogen bond [H2···S2 2.29 (3) Å, N2···S1 2.981 (2) Å and N2—H2···S1 145 (2)°].

Related literature

For related literature, see: Belhadj-Tahar et al. (1996); Contreras et al. (2004); Feroci et al. (2000); Feroci et al. (2003); Hou et al. (2006); Jansons (1976); Laus et al. (2001); Szulzewsky et al. (1984); Toumi et al. (2007).

S2. Experimental

The title compound was obtained from the electrolysis of racemic 1-phenylethylamine (0.5 g, 4.1 mmol) under glavanostatic conditions (I = 80 mA, 6.0 h, Q = 2.0 F/mole) in anhydrous acetonitrile (80 ml) as solvent and reagent in the presence of tetrabutylammonium perchlorate (3.2 g, 8.0 mmol) as supporting electrolyte. At the end of electrolysis, carbon disulfide (0.38 g, 5.0 mmol) was added with stirring for 1 h and then ethyl iodide (0.78 g, 5.0 mmol) was added and the mixture was stirred overnight. After the removal of acetonitrile under reduced pressure, the residue was quenched with water and extracted with diethyl ether. The resulting product was chromatographed on silica gel (mesh 60, ethyl acetate/hexanes 30/70) to afford a pure product (yield: 73%, m.p. 354 K). Crystals suitable for X-ray analysis were grown by slow evaporation of a chloroform solution. The title compound was characterized by ¹H, ¹³C NMR and MS spectra anlysis. ¹H NMR (CDCl₃, 300 MHz): 1.30 (t, ³J = 7 Hz, 3H); 1.60 (d, ³J = 6 Hz, 3H); 2.36 (s, 3H); 3.20 (q, ³J = 7 Hz, 2H); 5.2 (quint, ³J = 6 Hz, 1H);7.20–7.50 (m, 5H, H_ar); 14.1 (br, d, ³J = 6 Hz, 1H, intramolecularly bonded NH).¹³C NMR (CDCl₃ + DMSO, 75 MHz): 12.9; 19.2; 23.3; 27.6; 54.6; 93.5; 118.1; 125.9; 127.8; 128.9; 141.3; 167.5; 206.6. MS (EI, 70 eV): m/z (%): 290 (10) (M⁺); 261 (6) (M - Et)⁺; 229 (18) (M - SEt)⁺; 196 (4); 185 (14) (M - CS₂Et)⁺; 125 (13); 105 (100) (PhCHCH₃)⁺; 77 (18) (Ph)⁺; 42 (4). CI-HRMS (CH₄): 291.099 (M+H)⁺. IR (NaCl): ν = 3150 (m, broad, intramolecularly bonded NH), 2195 (conjugated C≡N), 1600 (S, conjugated C=C, C_ar—C_ar), 1261 (S, conjugated C—N), 1240 (C—N), 1090 (C=S).

S3. Refinement

The N-bound H atom was located in a difference Fourier map and refined freely. C-bound H atoms were placed in calculated positions and constrained to ride on their carrier atoms, with C—H = 0.95–0.98 Å; the isotropic displacement parameters of the H atoms were refined freely.

Computing details

Data collection: CAD-4 EXPRESS (Duisenberg, 1992; Macíček & Yordanov, 1992); cell refinement: CAD-4 EXPRESS; data reduction: MolEN (Fair, 1990); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Brandenburg, 1998); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. The molecular structure of (I), showing the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. Compounds (I)–(III).

(Z)-Ethyl 2-cyano-3-(1-phenylethylamino)but-2-enedithioate

Crystal data

C15H18N2S2	F(000) = 616
Mr = 290.43	Dx = 1.243 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 25 reflections
a = 8.997 (3) Å	θ = 11.8–14.5°
b = 10.645 (3) Å	µ = 0.33 mm^−1
c = 16.293 (3) Å	T = 298 K
β = 95.97 (2)°	Prism, yellow
V = 1552.0 (7) Å^3	0.50 × 0.50 × 0.50 mm
Z = 4

Data collection

Enraf–Nonius CAD-4 diffractometer	2592 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.014
Graphite monochromator	θmax = 27.0°, θmin = 2.3°
ω/2θ scans	h = −11→1
Absorption correction: ψ scan (North et al., 1968)	k = −1→13
Tmin = 0.816, Tmax = 0.847	l = −20→20
4376 measured reflections	2 standard reflections every 120 min
3386 independent reflections	intensity decay: 4%

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)] = 0.043	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.122	H atoms treated by a mixture of independent and constrained refinement
S = 1.02	w = 1/[σ^2(Fo^2) + (0.0545P)^2 + 0.7692P] where P = (Fo^2 + 2Fc^2)/3
3386 reflections	(Δ/σ)max = 0.001
198 parameters	Δρmax = 0.71 e Å^−3
0 restraints	Δρmin = −0.47 e Å^−3

Special details

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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 > σ(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
S1	0.15033 (7)	0.11219 (5)	0.04503 (4)	0.0524 (2)
S2	0.22913 (9)	0.36720 (5)	−0.01435 (4)	0.0638 (2)
N1	0.4329 (3)	0.3250 (2)	−0.1745 (1)	0.0734 (6)
N2	0.2968 (2)	−0.0649 (2)	−0.0632 (1)	0.0423 (4)
C1	0.2388 (2)	0.2010 (2)	−0.0191 (1)	0.0393 (4)
C2	0.3250 (2)	0.1568 (2)	−0.0825 (1)	0.0378 (4)
C3	0.3574 (2)	0.0289 (2)	−0.1003 (1)	0.0387 (4)
C4	0.4662 (3)	−0.0013 (2)	−0.1614 (1)	0.0529 (5)
H14	0.5581	−0.0355	−0.1323	0.11 (1)*
H24	0.4894	0.0753	−0.1909	0.09 (1)*
H34	0.4219	−0.0635	−0.2011	0.080 (9)*
C5	0.3862 (3)	0.2501 (2)	−0.1332 (1)	0.0483 (5)
C6	0.3188 (2)	−0.2004 (2)	−0.0763 (1)	0.0445 (5)
H6	0.4278	−0.2162	−0.0785	0.059 (7)*
C7	0.2692 (3)	−0.2692 (2)	−0.0012 (1)	0.0608 (7)
H17	0.3252	−0.2368	0.0492	0.067 (7)*
H27	0.2887	−0.3594	−0.0062	0.09 (1)*
H37	0.1621	−0.2556	0.0014	0.09 (1)*
C8	0.2339 (2)	−0.2475 (2)	−0.1568 (1)	0.0407 (4)
C9	0.2656 (3)	−0.3681 (2)	−0.1843 (1)	0.0502 (5)
H9	0.3402	−0.4173	−0.1538	0.067 (8)*
C10	0.1892 (3)	−0.4165 (2)	−0.2558 (2)	0.0584 (6)
H10	0.2110	−0.4989	−0.2735	0.066 (7)*
C11	0.0822 (3)	−0.3459 (3)	−0.3009 (1)	0.0610 (6)
H11	0.0315	−0.3787	−0.3504	0.084 (9)*
C12	0.0484 (3)	−0.2269 (3)	−0.2742 (1)	0.0613 (6)
H12	−0.0262	−0.1782	−0.3052	0.085 (9)*
C13	0.1233 (2)	−0.1782 (2)	−0.2020 (1)	0.0498 (5)
H13	0.0984	−0.0969	−0.1836	0.053 (6)*
C14	0.1419 (3)	0.4006 (2)	0.0788 (2)	0.0622 (6)
H114	0.0915	0.4833	0.0729	0.09 (1)*
H214	0.0645	0.3363	0.0855	0.073 (8)*
C15	0.2510 (4)	0.4020 (4)	0.1541 (2)	0.087 (1)
H15	0.2927	0.3176	0.1638	0.10 (1)*
H25	0.2002	0.4281	0.2017	0.12 (1)*
H35	0.3317	0.4612	0.1463	0.12 (1)*
H2	0.241 (3)	−0.047 (2)	−0.030 (2)	0.060 (8)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0661 (4)	0.0413 (3)	0.0534 (3)	−0.0013 (3)	0.0239 (3)	0.0014 (2)
S2	0.1007 (5)	0.0330 (3)	0.0607 (4)	−0.0001 (3)	0.0222 (3)	−0.0020 (2)
N1	0.095 (2)	0.056 (1)	0.074 (1)	−0.008 (1)	0.030 (1)	0.016 (1)
N2	0.048 (1)	0.0332 (9)	0.047 (1)	−0.0002 (7)	0.0095 (8)	−0.0036 (7)
C1	0.046 (1)	0.0322 (9)	0.038 (1)	−0.0009 (8)	−0.0010 (8)	−0.0012 (8)
C2	0.041 (1)	0.0347 (9)	0.0369 (9)	−0.0035 (8)	0.0023 (8)	0.0010 (8)
C3	0.038 (1)	0.041 (1)	0.0362 (9)	−0.0017 (8)	−0.0003 (8)	−0.0007 (8)
C4	0.051 (1)	0.054 (1)	0.055 (1)	0.003 (1)	0.016 (1)	−0.003 (1)
C5	0.056 (1)	0.042 (1)	0.047 (1)	−0.001 (1)	0.008 (1)	0.0033 (9)
C6	0.047 (1)	0.032 (1)	0.053 (1)	0.0032 (8)	−0.0013 (9)	−0.0027 (9)
C7	0.086 (2)	0.042 (1)	0.051 (1)	−0.004 (1)	−0.009 (1)	0.005 (1)
C8	0.042 (1)	0.035 (1)	0.046 (1)	−0.0002 (8)	0.0080 (8)	−0.0019 (8)
C9	0.048 (1)	0.041 (1)	0.062 (1)	0.004 (1)	0.009 (1)	−0.007 (1)
C10	0.063 (1)	0.049 (1)	0.066 (1)	−0.006 (1)	0.018 (1)	−0.021 (1)
C11	0.064 (1)	0.069 (2)	0.050 (1)	−0.013 (1)	0.008 (1)	−0.015 (1)
C12	0.060 (1)	0.065 (2)	0.056 (1)	0.003 (1)	−0.006 (1)	0.001 (1)
C13	0.054 (1)	0.042 (1)	0.053 (1)	0.005 (1)	0.002 (1)	−0.003 (1)
C14	0.069 (2)	0.048 (1)	0.070 (2)	0.001 (1)	0.013 (1)	−0.015 (1)
C15	0.090 (2)	0.102 (3)	0.071 (2)	−0.012 (2)	0.008 (2)	−0.026 (2)

Geometric parameters (Å, º)

S1—C1	1.671 (2)	C7—H37	0.98
S2—C1	1.773 (2)	C8—C13	1.388 (3)
S2—C14	1.815 (3)	C8—C9	1.398 (3)
N1—C5	1.151 (3)	C9—C10	1.388 (3)
N2—C3	1.315 (3)	C9—H9	0.95
N2—C6	1.474 (3)	C10—C11	1.373 (4)
N2—H2	0.80 (3)	C10—H10	0.95
C1—C2	1.434 (3)	C11—C12	1.384 (4)
C2—C3	1.428 (3)	C11—H11	0.95
C2—C5	1.437 (3)	C12—C13	1.394 (3)
C3—C4	1.502 (3)	C12—H12	0.95
C4—H14	0.98	C13—H13	0.95
C4—H24	0.98	C14—C15	1.489 (4)
C4—H34	0.98	C14—H114	0.99
C6—C7	1.531 (3)	C14—H214	0.99
C6—C8	1.532 (3)	C15—H15	0.98
C6—H6	1.00	C15—H25	0.98
C7—H17	0.98	C15—H35	0.98
C7—H27	0.98
C1—S2—C14	105.0 (1)	H27—C7—H37	109.5
C3—N2—C6	127.5 (2)	C13—C8—C9	118.5 (2)
C3—N2—H2	117 (2)	C13—C8—C6	123.11 (18)
C6—N2—H2	115 (2)	C9—C8—C6	118.38 (19)
C2—C1—S1	126.4 (1)	C10—C9—C8	120.7 (2)
C2—C1—S2	113.0 (1)	C10—C9—H9	119.6
S1—C1—S2	120.6 (1)	C8—C9—H9	119.6
C3—C2—C1	126.61 (17)	C11—C10—C9	120.3 (2)
C3—C2—C5	116.29 (18)	C11—C10—H10	119.9
C1—C2—C5	117.10 (18)	C9—C10—H10	119.9
N2—C3—C2	121.83 (18)	C10—C11—C12	119.8 (2)
N2—C3—C4	118.16 (19)	C10—C11—H11	120.1
C2—C3—C4	119.99 (18)	C12—C11—H11	120.1
C3—C4—H14	109.5	C11—C12—C13	120.2 (2)
C3—C4—H24	109.5	C11—C12—H12	119.9
H14—C4—H24	109.5	C13—C12—H12	119.9
C3—C4—H34	109.5	C8—C13—C12	120.5 (2)
H14—C4—H34	109.5	C8—C13—H13	119.8
H24—C4—H34	109.5	C12—C13—H13	119.8
N1—C5—C2	178.9 (3)	C15—C14—S2	112.7 (2)
N2—C6—C7	107.36 (18)	C15—C14—H114	109.1
N2—C6—C8	112.45 (17)	S2—C14—H114	109.1
C7—C6—C8	111.51 (18)	C15—C14—H214	109.1
N2—C6—H6	108.5	S2—C14—H214	109.1
C7—C6—H6	108.5	H114—C14—H214	107.8
C8—C6—H6	108.5	C14—C15—H15	109.5
C6—C7—H17	109.5	C14—C15—H25	109.5
C6—C7—H27	109.5	H15—C15—H25	109.5
H17—C7—H27	109.5	C14—C15—H35	109.5
C6—C7—H37	109.5	H15—C15—H35	109.5
H17—C7—H37	109.5	H25—C15—H35	109.5