O-Ethyl S-[1-(3,4-dimethoxy­phen­yl)-2-(hydroxyimino)­prop­yl] dithio­carbonate

The stereogenic centre in the title compound, C₁₄H₁₉NO₄S₂, is substituted with a dithio­carbonate, an ethyl­oximino and a 3,4-dimethoxy­phenyl group, as well as an H atom. Tandem hydrogen-bonding occurs between enantiomers to produce dimers, in which the oxime H atom serves as donor toward the oxime N atom of an adjacent mol­ecule.

Key indicators

• Single-crystal X-ray study
• T = 299 K
• Mean [sigma](C-C) = 0.006 Å
• R factor = 0.071
• wR factor = 0.220
• Data-to-parameter ratio = 16.4

checkCIF/PLATON results

No syntax errors found



Alert level A
PLAT029_ALERT_3_A _diffrn_measured_fraction_theta_full Low .......       0.92

Author Response: I wish to point out that the data set only has a completeness of 95% up to theta=22.5\%. Up to theta =26.4\%, the completeness reaches a value of 91.5%, which still is considered to be sufficient in order to unambigiously solve the structure and refine the structure model reliably.

Alert level B
PLAT417_ALERT_2_B Short Inter D-H..H-D       H1     ..  H1      ..       2.00 Ang.

Alert level C
ABSTM02_ALERT_3_C  The ratio of Tmax/Tmin expected RT(exp) is > 1.10
            Absorption corrections should be applied.
            Tmin and Tmax expected:      0.809     0.924
            RT(exp) =      1.142
REFLT03_ALERT_3_C  Reflection count < 95% complete
           From the CIF: _diffrn_reflns_theta_max           26.37
           From the CIF: _diffrn_reflns_theta_full          26.37
           From the CIF: _reflns_number_total               3161
           TEST2: Reflns within _diffrn_reflns_theta_max
           Count of symmetry unique reflns         3452
           Completeness (_total/calc)             91.57%
PLAT022_ALERT_3_C Ratio Unique / Expected Reflections too Low ....       0.92
PLAT057_ALERT_3_C Correction for Absorption Required   RT(exp) ...       1.15
PLAT063_ALERT_3_C Crystal Probably too Large for Beam Size .......       0.66 mm
PLAT125_ALERT_4_C No _symmetry_space_group_name_Hall Given .......          ?
PLAT340_ALERT_3_C Low Bond Precision on C-C bonds (x 1000) Ang ...          6
PLAT380_ALERT_4_C Check Incorrectly? Oriented X(sp2)-Methyl Moiety         C2
PLAT790_ALERT_4_C Centre of Gravity not Within Unit Cell: Resd.  #          1
              C14 H19 N O4 S2

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

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

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S1. Comment

The title compound, (I), is the starting material for the synthesis of N-hydroxy-5-(3,4-dimethoxyphenyl)-4-methylthiazole-2(3H)-thione, a molecule of notable interest for investigating substituent effects on the location of absorption bands caused by visible to near-UV light excitations in heterocyclic alkoxyl radical precursors (Hartung, Špehar et al., 2005). Compound (I) has been crystallized and studied by X-ray diffraction in order to gain an understanding of its structural details in the solid state.

The stereogenic centre, atom C4, is substituted by three virtually planar groups, viz a 3,4-dimethoxyphenyl, an O-ethyl dithiocarbonate and an ethyloximino group, and by one H atom (Fig. 1). The heteroatoms and the central C atom of the dithiocarbonate group are located in a plane [deviation of O2 = 0.012 (1) Å]. The stereogenic bonds associated with the latter entity adopt an (E) arrangement for C1—S2 and (Z) geometry for C1—O2. The C1—S1 distance [1.639 (4) Å] is smaller than the mean value for the C═S double bond in O,S-dialkyldithiocarbonates [1.67 (2) Å; Abrahamson & Innes, 1974; Allen et al., 1987; Duarte et al., 1989]. The connectivities S2—C1 and S2—C4 differ in length due to different hybridization of the associated C atoms (Zhang et al., 2003, Hartung, Schmidt et al., 2005). The oxime group adopts an (E) configuration. The distances N1—O1 and N1═C3 distances agree with mean values for both types of connectivities (Allen et al., 1987; Hartung et al., 2004).

The unit cell (Z = 4) comprises a 1:1 mixture of (S) and (R) enantiomers. A view along 001 indicates that these enantiomers are linked via a tandem hydrogen bond to provide dimers. The oxime H atom serves as the donor toward the oxime N atom of an adjacent molecule (Fig. 2, Table 2).

S2. Experimental

Crystals of (I) suitable for X-ray diffraction were obtained by slowly concentrating a saturated solution of (I) in CH₂Cl₂ at 298 K. (m.p. 375–377 K). R_f = 0.35 [SiO₂, petroleum ether/Et₂O = 2/1 (v/v)]. Analysis, calculated for C₁₄H₁₉NO₄S₂: C 51.04, H 5.81, N 4.25, S 19.47%; found: C 51.21, H 5.63, N 4.33, S 19.31%. MS (70 eV, EI): m/z (%) 329 (1), 300 (3), 208 (100), 191 (33), 182 (30). ¹H NMR (CDCl₃, 400 MHz, δ, p.p.m.): 1.38 (t, 3H, J = 7.2 Hz), 1.91 (s, 3H), 3.86 (s, 3H), 3.87 (s, 3H), 4.61 (q, 2H, J = 7.1 Hz), 5.50 (s, 1H), 6.81 (d, 1H, J = 8.2 Hz), 6.88 (d, 1H, J = 1.9 Hz), 6.93 (dd, 1H, J = 1.9, 8.2 Hz). ¹³C NMR (CDCl₃, 100 MHz, δ, p.p.m.): 13.9, 14.1, 56.3, 56.4, 58.6, 70.6, 111.6, 112.0, 121.5, 128.8, 149.4, 156.4, 213.6 (C═S).

S3. Refinement

Atom H1 was located in a difference Fourier map and its atomic coordinates were refined, with U_iso(H1) = 1.2U_eq(O1). All other H atoms were positioned geometrically and treated as riding atoms, with C—H distances in the range 0.93–0.96 Å and with U_iso(H) = 1.2U_eq(C).

Computing details

Data collection: CrysAlis CCD (Oxford Diffraction, 2002); cell refinement: CrysAlis RED (Oxford Diffraction, 2002); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: PLATON2002 (Spek, 1990, 2003) and ORTEP-3 (Farrugia, 1997, 2005); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. The molecular structure of (I). Displacement ellipsoids are drawn at the 50% probability level.
	Fig. 2. Visualization of the hydrogen bonding (dashed lines) between molecules of (I), viewed along (001). O atoms are depicted in red, N atoms in blue and S atoms in yellow.

O-Ethyl-S-[1-(3,4-dimethoxyphenyl)-2-oximinopropyl]dithiocarbonate

Crystal data

C14H19NO4S2	Dx = 1.297 Mg m^−3
Mr = 329.42	Melting point: 375 K
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 9.114 (2) Å	Cell parameters from 1190 reflections
b = 7.319 (2) Å	θ = 2.6–22.0°
c = 25.575 (6) Å	µ = 0.33 mm^−1
β = 98.66 (2)°	T = 299 K
V = 1686.5 (7) Å^3	Prism, light brown
Z = 4	0.66 × 0.60 × 0.24 mm
F(000) = 696

Data collection

Oxford Diffraction Xcalibur CCD diffractometer	1809 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	Rint = 0.047
Graphite monochromator	θmax = 26.4°, θmin = 4.1°
Detector resolution: Sapphire CCD detector pixels mm^-1	h = −11→11
Rotation method data acquisition using phi scans	k = −9→8
4733 measured reflections	l = −31→31
3161 independent reflections

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)] = 0.071	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.220	H atoms treated by a mixture of independent and constrained refinement
S = 0.93	w = 1/[σ^2(Fo^2) + (0.124P)^2 + 1.166P] where P = (Fo^2 + 2Fc^2)/3
3161 reflections	(Δ/σ)max = 0.002
193 parameters	Δρmax = 0.40 e Å^−3
0 restraints	Δρmin = −0.42 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
C1	−0.0010 (4)	0.8794 (6)	0.07504 (14)	0.0523 (9)
C2	0.3430 (5)	1.4444 (5)	0.04715 (18)	0.0647 (11)
H2A	0.4235	1.4745	0.0285	0.078*
H2B	0.3648	1.4879	0.0829	0.078*
H2C	0.2535	1.5009	0.0299	0.078*
C3	0.3229 (4)	1.2427 (5)	0.04738 (14)	0.0484 (9)
C4	0.2029 (4)	1.1649 (5)	0.07455 (14)	0.0468 (9)
H4	0.1122	1.2357	0.0635	0.056*
C5	0.2445 (4)	1.1841 (5)	0.13463 (14)	0.0455 (8)
C6	0.1792 (4)	1.3210 (5)	0.16146 (14)	0.0494 (9)
H6	0.1089	1.3986	0.1430	0.059*
C7	0.2189 (4)	1.3412 (5)	0.21547 (15)	0.0509 (9)
C8	0.3220 (4)	1.2242 (6)	0.24348 (14)	0.0524 (9)
C9	0.3886 (5)	1.0923 (6)	0.21735 (16)	0.0643 (11)
H9	0.4591	1.0148	0.2358	0.077*
C10	0.3494 (5)	1.0753 (6)	0.16247 (17)	0.0619 (11)
H10	0.3963	0.9873	0.1446	0.074*
C11	0.0659 (8)	1.6037 (9)	0.2184 (2)	0.113 (2)
H11A	0.0337	1.6854	0.2438	0.135*
H11B	−0.0188	1.5445	0.1986	0.135*
H11C	0.1177	1.6715	0.1947	0.135*
C12	0.4408 (7)	1.1231 (8)	0.32818 (19)	0.0921 (17)
H12C	0.5407	1.1325	0.3207	0.110*
H12B	0.4039	1.0021	0.3198	0.110*
H12A	0.4397	1.1471	0.3650	0.110*
C13	−0.2032 (5)	0.9993 (7)	0.1135 (2)	0.0775 (14)
H13A	−0.1927	0.9192	0.1441	0.093*
H13B	−0.2758	0.9466	0.0860	0.093*
C14	−0.2513 (6)	1.1834 (9)	0.1279 (3)	0.107 (2)
H14A	−0.2610	1.2613	0.0974	0.128*
H14B	−0.1789	1.2337	0.1552	0.128*
H14C	−0.3452	1.1745	0.1404	0.128*
N1	0.4023 (4)	1.1293 (5)	0.02587 (13)	0.0568 (9)
O1	0.5120 (4)	1.2189 (4)	0.00144 (14)	0.0753 (10)
H1	0.558 (6)	1.113 (8)	−0.0050 (19)	0.090*
O2	−0.0617 (3)	1.0207 (4)	0.09477 (11)	0.0606 (8)
O3	0.1610 (4)	1.4719 (5)	0.24482 (11)	0.0753 (9)
O4	0.3500 (3)	1.2518 (4)	0.29732 (11)	0.0696 (8)
S1	−0.06609 (14)	0.67062 (17)	0.06848 (5)	0.0759 (4)
S2	0.16706 (11)	0.92796 (14)	0.05342 (4)	0.0576 (4)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
C1	0.057 (2)	0.055 (2)	0.045 (2)	−0.0034 (19)	0.0096 (16)	0.0060 (18)
C2	0.082 (3)	0.049 (2)	0.069 (3)	−0.001 (2)	0.032 (2)	−0.006 (2)
C3	0.055 (2)	0.046 (2)	0.0460 (19)	−0.0016 (18)	0.0154 (16)	−0.0014 (16)
C4	0.056 (2)	0.042 (2)	0.0464 (19)	−0.0010 (17)	0.0197 (16)	−0.0024 (16)
C5	0.0499 (18)	0.040 (2)	0.051 (2)	0.0018 (17)	0.0212 (15)	−0.0030 (16)
C6	0.0524 (19)	0.047 (2)	0.052 (2)	0.0091 (17)	0.0173 (16)	0.0034 (17)
C7	0.057 (2)	0.047 (2)	0.053 (2)	0.0045 (18)	0.0215 (17)	−0.0044 (17)
C8	0.060 (2)	0.053 (2)	0.046 (2)	0.0010 (19)	0.0160 (17)	0.0059 (17)
C9	0.068 (2)	0.067 (3)	0.060 (3)	0.017 (2)	0.013 (2)	0.011 (2)
C10	0.070 (2)	0.054 (3)	0.065 (3)	0.020 (2)	0.023 (2)	0.001 (2)
C11	0.141 (5)	0.115 (5)	0.079 (4)	0.078 (4)	0.009 (3)	−0.026 (3)
C12	0.128 (5)	0.079 (4)	0.064 (3)	0.020 (4)	−0.002 (3)	0.013 (3)
C13	0.064 (3)	0.097 (4)	0.079 (3)	−0.013 (3)	0.035 (2)	−0.008 (3)
C14	0.077 (3)	0.121 (5)	0.130 (5)	0.005 (4)	0.042 (3)	−0.023 (4)
N1	0.0624 (19)	0.050 (2)	0.066 (2)	0.0010 (16)	0.0365 (16)	0.0082 (16)
O1	0.085 (2)	0.0531 (18)	0.102 (2)	−0.0042 (16)	0.0606 (18)	0.0027 (17)
O2	0.0580 (15)	0.0671 (19)	0.0624 (17)	−0.0074 (14)	0.0272 (13)	−0.0030 (14)
O3	0.097 (2)	0.079 (2)	0.0514 (16)	0.0354 (18)	0.0134 (15)	−0.0110 (15)
O4	0.086 (2)	0.073 (2)	0.0508 (16)	0.0123 (17)	0.0118 (14)	0.0061 (14)
S1	0.0790 (8)	0.0609 (8)	0.0857 (9)	−0.0157 (6)	0.0057 (6)	0.0069 (6)
S2	0.0633 (6)	0.0487 (6)	0.0655 (7)	−0.0025 (5)	0.0253 (5)	−0.0077 (5)

Geometric parameters (Å, º)

C1—O2	1.309 (5)	C9—C10	1.401 (6)
C1—S1	1.639 (4)	C9—H9	0.9300
C1—S2	1.741 (4)	C10—H10	0.9300
C2—C3	1.488 (5)	C11—O3	1.400 (6)
C2—H2A	0.9600	C11—H11A	0.9600
C2—H2B	0.9600	C11—H11B	0.9600
C2—H2C	0.9600	C11—H11C	0.9600
C3—N1	1.278 (5)	C12—O4	1.414 (6)
C3—C4	1.494 (5)	C12—H12C	0.9600
C4—C5	1.533 (5)	C12—H12B	0.9600
C4—S2	1.831 (4)	C12—H12A	0.9600
C4—H4	0.9800	C13—O2	1.451 (5)
C5—C10	1.360 (5)	C13—C14	1.480 (7)
C5—C6	1.397 (5)	C13—H13A	0.9700
C6—C7	1.382 (5)	C13—H13B	0.9700
C6—H6	0.9300	C14—H14A	0.9600
C7—C8	1.388 (5)	C14—H14B	0.9600
C7—O3	1.370 (4)	C14—H14C	0.9600
C8—C9	1.368 (6)	N1—O1	1.417 (4)
C8—O4	1.377 (5)	O1—H1	0.91 (6)
O2—C1—S1	127.5 (3)	C5—C10—C9	121.7 (4)
O2—C1—S2	113.9 (3)	C5—C10—H10	119.1
S1—C1—S2	118.7 (2)	C9—C10—H10	119.1
C3—C2—H2A	109.5	O3—C11—H11A	109.5
C3—C2—H2B	109.5	O3—C11—H11B	109.5
H2A—C2—H2B	109.5	H11A—C11—H11B	109.5
C3—C2—H2C	109.5	O3—C11—H11C	109.5
H2A—C2—H2C	109.5	H11A—C11—H11C	109.5
H2B—C2—H2C	109.5	H11B—C11—H11C	109.5
N1—C3—C2	124.4 (3)	O4—C12—H12C	109.5
N1—C3—C4	117.0 (3)	O4—C12—H12B	109.5
C2—C3—C4	118.6 (3)	H12C—C12—H12B	109.5
C3—C4—C5	110.1 (3)	O4—C12—H12A	109.5
C3—C4—S2	109.5 (2)	H12C—C12—H12A	109.5
C5—C4—S2	112.9 (3)	H12B—C12—H12A	109.5
C3—C4—H4	108.1	O2—C13—C14	107.2 (4)
C5—C4—H4	108.1	O2—C13—H13A	110.3
S2—C4—H4	108.1	C14—C13—H13A	110.3
C10—C5—C6	118.7 (3)	O2—C13—H13B	110.3
C10—C5—C4	121.3 (3)	C14—C13—H13B	110.3
C6—C5—C4	119.9 (3)	H13A—C13—H13B	108.5
C5—C6—C7	120.0 (3)	C13—C14—H14A	109.5
C5—C6—H6	120.0	C13—C14—H14B	109.5
C7—C6—H6	120.0	H14A—C14—H14B	109.5
C8—C7—O3	115.8 (3)	C13—C14—H14C	109.5
C8—C7—C6	120.3 (3)	H14A—C14—H14C	109.5
O3—C7—C6	123.9 (3)	H14B—C14—H14C	109.5
C9—C8—C7	120.0 (4)	C3—N1—O1	111.8 (3)
C9—C8—O4	124.3 (4)	N1—O1—H1	93 (3)
C7—C8—O4	115.8 (3)	C1—O2—C13	119.4 (3)
C8—C9—C10	119.1 (4)	C7—O3—C11	118.6 (3)
C8—C9—H9	120.4	C8—O4—C12	117.7 (3)
C10—C9—H9	120.4	C1—S2—C4	103.05 (18)
N1—C3—C4—C5	108.4 (4)	O4—C8—C9—C10	179.0 (4)
C2—C3—C4—C5	−71.4 (5)	C6—C5—C10—C9	2.6 (6)
N1—C3—C4—S2	−16.3 (4)	C4—C5—C10—C9	179.7 (4)
C2—C3—C4—S2	164.0 (3)	C8—C9—C10—C5	−1.4 (7)
C3—C4—C5—C10	−74.3 (4)	C2—C3—N1—O1	−0.2 (6)
S2—C4—C5—C10	48.4 (4)	C4—C3—N1—O1	−180.0 (3)
C3—C4—C5—C6	102.8 (4)	S1—C1—O2—C13	−0.3 (5)
S2—C4—C5—C6	−134.5 (3)	S2—C1—O2—C13	179.1 (3)
C10—C5—C6—C7	−1.5 (6)	C14—C13—O2—C1	−174.0 (4)
C4—C5—C6—C7	−178.6 (3)	C8—C7—O3—C11	174.7 (5)
C5—C6—C7—C8	−1.0 (6)	C6—C7—O3—C11	−6.0 (7)
C5—C6—C7—O3	179.7 (4)	C9—C8—O4—C12	−7.4 (6)
O3—C7—C8—C9	−178.3 (4)	C7—C8—O4—C12	172.8 (4)
C6—C7—C8—C9	2.3 (6)	O2—C1—S2—C4	6.1 (3)
O3—C7—C8—O4	1.5 (5)	S1—C1—S2—C4	−174.5 (2)
C6—C7—C8—O4	−177.8 (3)	C3—C4—S2—C1	−165.9 (3)
C7—C8—C9—C10	−1.1 (6)	C5—C4—S2—C1	71.1 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···N1^i	0.91 (6)	1.90 (6)	2.786 (5)	164 (5)

Symmetry code: (i) −x+1, −y+2, −z.