Ethyl 2-[(2-hy-droxy-benzyl-idene)amino]-6-methyl-4,5,6,7-tetra-hydro-thieno[2,3-c]pyridine-3-carboxyl-ate.

The title compound, C18H20N2O3S, exists as the phenol-imine form in the crystal and there are bifurcated intra-molecular O-H⋯(N/O) hydrogen bonds present. The conformation about the C=N bond is anti (1E); the C=N imine bond length is 1.287 (4) Å and the C=N-C angle is 122.5 (3)°. In the tetrahydrothienopyridine moiety, the six-membered ring has a flattened-boat conformation. In the crystal, mol-ecules are stacked nearly parallel to (110) and a weak C-H⋯π inter-action is observed. The carbonyl O atom is disordered over two positions and was refined with a fixed occupancy ratio of 0.7:0.3.

Related literature

For investigations of tautomerism and intra­molecular hydrogen bonds in 2-hy­droxy Schiff bases in both solution and the solid state, see: Hayvalı et al. (2003 ▶); Pizzala et al. (2000 ▶); Kaitner & Pavlovic (1996 ▶). For the role of tautomerism in Schiff bases in distinguishing their photochromic and thermochromic characteristics, see: Hadjoudis (1981 ▶); Dürr (1989 ▶); Moustakali-Mavridis et al. (1980 ▶). For keto-amine and phenol-imine forms observed in naphthaldimine and salicylaldimine Schiff bases, see: Gavranic et al. (1996 ▶); Kaitner & Pavlovic (1996 ▶); Pizzala et al. (2000 ▶); Hökelek et al. (2004 ▶). For related structures, see: Hökelek et al. (2000 ▶, 2004 ▶);Yıldız et al. (1998 ▶). For puckering parameters, see: Cremer & Pople (1975 ▶).

Experimental

Crystal data

C18H20N2O3S

M = 344.42

Orthorhombic,

a = 22.0243 (5) Å

b = 16.1559 (4) Å

c = 4.8055 (1) Å

V = 1709.90 (7) Å3

Z = 4

Mo Kα radiation

μ = 0.21 mm−1

T = 296 K

0.35 × 0.15 × 0.10 mm

Data collection

Bruker Kappa APEXII CCD area-detector diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T min = 0.912, T max = 0.980

11744 measured reflections

2778 independent reflections

2120 reflections with I > 2σ(I)

R int = 0.062

Refinement

R[F 2 > 2σ(F 2)] = 0.043

wR(F 2) = 0.104

S = 1.02

2778 reflections

236 parameters

1 restraint

H atoms treated by a mixture of independent and constrained refinement

Δρmax = 0.16 e Å−3

Δρmin = −0.16 e Å−3

Absolute structure: Flack (1983 ▶), 691 Friedel pairs

Flack parameter: 0.08 (11)

Data collection: APEX2 (Bruker, 2007 ▶); cell refinement: SAINT (Bruker, 2007 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▶); software used to prepare material for publication: WinGX (Farrugia, 2012 ▶) and PLATON (Spek, 2009 ▶).

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536813016474/su2610sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813016474/su2610Isup2.hkl

Click here for additional data file.

Supplementary material file. DOI: 10.1107/S1600536813016474/su2610Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C18H20N2O3S	F(000) = 728
Mr = 344.42	Dx = 1.338 Mg m−3
Orthorhombic, Pna21	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2c -2n	Cell parameters from 2064 reflections
a = 22.0243 (5) Å	θ = 3.1–23.9°
b = 16.1559 (4) Å	µ = 0.21 mm−1
c = 4.8055 (1) Å	T = 296 K
V = 1709.90 (7) Å3	Block, orange
Z = 4	0.35 × 0.15 × 0.10 mm

Bruker Kappa APEXII CCD area-detector diffractometer	2778 independent reflections
Radiation source: fine-focus sealed tube	2120 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.062
φ and ω scans	θmax = 27.0°, θmin = 1.6°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −28→28
Tmin = 0.912, Tmax = 0.980	k = −20→20
11744 measured reflections	l = −5→6

Refinement on F2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.043	H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.104	w = 1/[σ2(Fo2) + (0.0469P)2 + 0.1687P] where P = (Fo2 + 2Fc2)/3
S = 1.02	(Δ/σ)max = 0.001
2778 reflections	Δρmax = 0.16 e Å−3
236 parameters	Δρmin = −0.16 e Å−3
1 restraint	Absolute structure: Flack (1983), 691 Friedel pairs
Primary atom site location: structure-invariant direct methods	Flack parameter: 0.08 (11)

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.

	x	y	z	Uiso*/Ueq	Occ. (<1)
S1	0.29327 (3)	0.31834 (4)	−0.0279 (2)	0.0491 (2)
O1	0.10485 (13)	0.45699 (12)	0.4998 (7)	0.0729 (8)
H1	0.139 (2)	0.454 (3)	0.396 (12)	0.13 (2)*
O2A	0.2600 (4)	0.6160 (5)	−0.080 (3)	0.086 (2)	0.70
O2B	0.2404 (9)	0.6148 (14)	−0.184 (7)	0.113 (9)	0.30
O3	0.17722 (11)	0.54989 (12)	0.0569 (8)	0.0883 (10)
N1	0.19752 (11)	0.39116 (14)	0.2458 (6)	0.0487 (6)
N2	0.43249 (11)	0.42497 (15)	−0.4324 (6)	0.0524 (7)
C1	0.10020 (15)	0.38418 (19)	0.6356 (8)	0.0537 (8)
C2	0.05554 (16)	0.3758 (2)	0.8360 (8)	0.0656 (10)
H2	0.0303	0.4203	0.8765	0.079*
C3	0.04824 (15)	0.3022 (2)	0.9757 (10)	0.0681 (9)
H3	0.0176	0.2972	1.1080	0.082*
C4	0.08544 (16)	0.2361 (2)	0.9225 (8)	0.0649 (9)
H4	0.0803	0.1867	1.0189	0.078*
C5	0.13008 (15)	0.2433 (2)	0.7273 (8)	0.0568 (8)
H5	0.1553	0.1984	0.6919	0.068*
C6	0.13862 (13)	0.31758 (16)	0.5781 (7)	0.0459 (7)
C7	0.18721 (14)	0.32333 (19)	0.3779 (7)	0.0496 (8)
H7	0.2133 (13)	0.2791 (19)	0.362 (7)	0.058 (10)*
C8	0.24460 (12)	0.39946 (16)	0.0600 (7)	0.0449 (7)
C9	0.26209 (12)	0.47141 (15)	−0.0714 (8)	0.0453 (7)
C10	0.31599 (13)	0.46149 (16)	−0.2347 (7)	0.0458 (7)
C11	0.34991 (14)	0.52626 (18)	−0.3940 (8)	0.0577 (9)
H11A	0.3687	0.5645	−0.2645	0.069*
H11B	0.3216	0.5573	−0.5081	0.069*
C12	0.39840 (14)	0.48860 (19)	−0.5785 (7)	0.0569 (8)
H12A	0.3795	0.4647	−0.7420	0.068*
H12B	0.4260	0.5317	−0.6400	0.068*
C13	0.39395 (13)	0.35399 (18)	−0.3697 (7)	0.0517 (8)
H13A	0.4153	0.3161	−0.2474	0.062*
H13B	0.3841	0.3248	−0.5402	0.062*
C14	0.33712 (13)	0.38294 (17)	−0.2328 (7)	0.0468 (7)
C15	0.48474 (16)	0.3986 (2)	−0.5965 (8)	0.0727 (11)
H15A	0.5112	0.4449	−0.6272	0.109*
H15B	0.4711	0.3773	−0.7722	0.109*
H15C	0.5063	0.3561	−0.4979	0.109*
C16	0.23215 (14)	0.55284 (17)	−0.0432 (10)	0.0571 (8)
C17	0.1444 (2)	0.6277 (2)	0.0843 (15)	0.1079 (19)
H17A	0.1400	0.6413	0.2799	0.129*
H17B	0.1674	0.6716	−0.0041	0.129*
C18	0.0884 (2)	0.6222 (3)	−0.036 (2)	0.166 (4)
H18A	0.0663	0.6724	−0.0026	0.249*
H18B	0.0666	0.5764	0.0434	0.249*
H18C	0.0928	0.6139	−0.2325	0.249*

	U11	U22	U33	U12	U13	U23
S1	0.0510 (4)	0.0387 (3)	0.0577 (5)	−0.0018 (3)	−0.0006 (4)	0.0037 (4)
O1	0.0915 (18)	0.0470 (12)	0.080 (2)	0.0143 (11)	0.0188 (17)	0.0050 (14)
O2B	0.071 (12)	0.067 (9)	0.20 (3)	0.008 (8)	0.023 (12)	0.057 (13)
O2A	0.074 (5)	0.034 (2)	0.150 (8)	−0.008 (3)	0.006 (5)	0.000 (4)
O3	0.0702 (15)	0.0412 (11)	0.153 (3)	0.0134 (10)	0.0125 (18)	0.0042 (17)
N1	0.0494 (13)	0.0428 (13)	0.0538 (17)	−0.0065 (10)	−0.0035 (13)	−0.0020 (12)
N2	0.0510 (14)	0.0611 (15)	0.0451 (16)	−0.0100 (12)	−0.0020 (12)	−0.0006 (13)
C1	0.0553 (18)	0.0520 (17)	0.054 (2)	−0.0013 (14)	−0.0023 (16)	−0.0028 (16)
C2	0.068 (2)	0.059 (2)	0.070 (3)	0.0040 (16)	0.0080 (19)	−0.0106 (19)
C3	0.0651 (18)	0.078 (2)	0.061 (2)	−0.0085 (17)	0.014 (2)	−0.001 (2)
C4	0.072 (2)	0.0601 (18)	0.062 (3)	−0.0068 (16)	0.006 (2)	0.0011 (19)
C5	0.0626 (19)	0.0486 (17)	0.059 (2)	−0.0020 (15)	0.0021 (18)	−0.0007 (16)
C6	0.0500 (16)	0.0436 (15)	0.0440 (17)	−0.0025 (12)	−0.0052 (14)	−0.0033 (14)
C7	0.0480 (16)	0.0423 (16)	0.059 (2)	−0.0010 (13)	−0.0046 (14)	−0.0015 (15)
C8	0.0411 (14)	0.0402 (14)	0.053 (2)	−0.0044 (11)	−0.0078 (13)	−0.0001 (14)
C9	0.0470 (14)	0.0384 (13)	0.050 (2)	−0.0062 (11)	−0.0098 (16)	−0.0007 (15)
C10	0.0487 (15)	0.0394 (15)	0.0494 (19)	−0.0056 (12)	−0.0098 (16)	−0.0005 (14)
C11	0.0621 (19)	0.0505 (17)	0.061 (2)	−0.0111 (15)	−0.0065 (18)	0.0088 (17)
C12	0.0663 (19)	0.0605 (17)	0.044 (2)	−0.0129 (15)	−0.0008 (17)	0.0017 (17)
C13	0.0527 (17)	0.0532 (16)	0.049 (2)	−0.0044 (14)	−0.0063 (15)	0.0006 (16)
C14	0.0450 (15)	0.0449 (16)	0.051 (2)	−0.0069 (12)	−0.0093 (15)	0.0025 (15)
C15	0.065 (2)	0.092 (3)	0.061 (3)	−0.0069 (18)	0.0067 (19)	−0.001 (2)
C16	0.0576 (17)	0.0414 (15)	0.072 (2)	−0.0035 (13)	−0.005 (2)	0.001 (2)
C17	0.095 (3)	0.0472 (19)	0.182 (6)	0.025 (2)	0.000 (4)	−0.009 (3)
C18	0.108 (4)	0.109 (4)	0.280 (10)	0.057 (3)	−0.054 (6)	−0.071 (6)

S1—C8	1.745 (3)	C9—C16	1.478 (4)
S1—C14	1.730 (3)	C10—C11	1.497 (4)
O1—H1	0.91 (5)	C11—C12	1.515 (5)
O2A—O2B	0.66 (3)	C11—H11A	0.9700
O3—C17	1.455 (4)	C11—H11B	0.9700
N1—C8	1.375 (4)	C12—H12A	0.9700
N2—C12	1.454 (4)	C12—H12B	0.9700
N2—C15	1.459 (4)	C13—N2	1.458 (4)
C1—O1	1.349 (4)	C13—C14	1.489 (4)
C2—C1	1.383 (5)	C13—H13A	0.9700
C2—H2	0.9300	C13—H13B	0.9700
C3—C2	1.375 (5)	C14—C10	1.352 (4)
C3—C4	1.370 (4)	C15—H15A	0.9600
C3—H3	0.9300	C15—H15B	0.9600
C4—C5	1.364 (5)	C15—H15C	0.9600
C4—H4	0.9300	C16—O2A	1.203 (10)
C5—C6	1.411 (4)	C16—O2B	1.22 (3)
C5—H5	0.9300	C16—O3	1.303 (4)
C6—C1	1.396 (4)	C17—C18	1.366 (7)
C7—N1	1.287 (4)	C17—H17A	0.9700
C7—C6	1.442 (4)	C17—H17B	0.9700
C7—H7	0.92 (3)	C18—H18A	0.9600
C8—C9	1.378 (4)	C18—H18B	0.9600
C9—C10	1.432 (4)	C18—H18C	0.9600
C14—S1—C8	91.59 (14)	C12—C11—H11B	109.3
C1—O1—H1	106 (3)	H11A—C11—H11B	107.9
C16—O3—C17	117.6 (3)	N2—C12—C11	111.4 (3)
C7—N1—C8	122.5 (3)	N2—C12—H12A	109.3
C12—N2—C13	110.8 (2)	N2—C12—H12B	109.3
C12—N2—C15	110.7 (3)	C11—C12—H12A	109.3
C15—N2—C13	109.9 (3)	C11—C12—H12B	109.3
O1—C1—C2	118.4 (3)	H12A—C12—H12B	108.0
O1—C1—C6	122.0 (3)	N2—C13—C14	109.5 (2)
C2—C1—C6	119.6 (3)	N2—C13—H13A	109.8
C1—C2—H2	119.7	N2—C13—H13B	109.8
C3—C2—C1	120.5 (3)	C14—C13—H13A	109.8
C3—C2—H2	119.7	C14—C13—H13B	109.8
C2—C3—H3	119.6	H13A—C13—H13B	108.2
C4—C3—C2	120.9 (4)	C10—C14—S1	112.2 (2)
C4—C3—H3	119.6	C10—C14—C13	125.5 (3)
C3—C4—H4	120.2	C13—C14—S1	122.1 (2)
C5—C4—C3	119.6 (3)	N2—C15—H15A	109.5
C5—C4—H4	120.2	N2—C15—H15B	109.5
C4—C5—C6	121.2 (3)	N2—C15—H15C	109.5
C4—C5—H5	119.4	H15A—C15—H15B	109.5
C6—C5—H5	119.4	H15A—C15—H15C	109.5
C1—C6—C5	118.3 (3)	H15B—C15—H15C	109.5
C1—C6—C7	122.1 (3)	O2A—C16—O3	123.9 (5)
C5—C6—C7	119.5 (3)	O2A—C16—C9	120.9 (5)
N1—C7—C6	121.0 (3)	O2B—C16—O3	111.8 (11)
N1—C7—H7	121 (2)	O2B—C16—C9	127.8 (14)
C6—C7—H7	118 (2)	O3—C16—C9	114.6 (3)
N1—C8—S1	123.2 (2)	C18—C17—O3	110.8 (4)
N1—C8—C9	126.2 (3)	C18—C17—H17A	109.5
C9—C8—S1	110.5 (2)	C18—C17—H17B	109.5
C8—C9—C10	112.9 (2)	O3—C17—H17A	109.5
C8—C9—C16	125.8 (3)	O3—C17—H17B	109.5
C10—C9—C16	121.3 (3)	H17A—C17—H17B	108.1
C9—C10—C11	128.0 (3)	C17—C18—H18A	109.5
C14—C10—C9	112.8 (3)	C17—C18—H18B	109.5
C14—C10—C11	119.2 (3)	C17—C18—H18C	109.5
C10—C11—C12	111.7 (2)	H18A—C18—H18B	109.5
C10—C11—H11A	109.3	H18A—C18—H18C	109.5
C10—C11—H11B	109.3	H18B—C18—H18C	109.5
C12—C11—H11A	109.3
C14—S1—C8—N1	−175.9 (3)	C8—C9—C10—C14	2.1 (4)
C14—S1—C8—C9	1.3 (3)	C16—C9—C10—C11	0.3 (5)
C8—S1—C14—C10	−0.1 (3)	C16—C9—C10—C14	179.2 (3)
C8—S1—C14—C13	175.6 (3)	C8—C9—C16—O2A	153.8 (7)
C16—O3—C17—C18	129.0 (6)	C8—C9—C16—O2B	−168.6 (14)
C7—N1—C8—S1	2.8 (4)	C8—C9—C16—O3	−17.9 (5)
C7—N1—C8—C9	−173.9 (3)	C10—C9—C16—O2A	−22.9 (8)
C13—N2—C12—C11	66.6 (3)	C10—C9—C16—O2B	14.7 (14)
C15—N2—C12—C11	−171.1 (3)	C10—C9—C16—O3	165.4 (3)
C3—C2—C1—O1	178.6 (4)	C9—C10—C11—C12	−170.4 (3)
C3—C2—C1—C6	−0.9 (5)	C14—C10—C11—C12	10.8 (4)
C4—C3—C2—C1	0.9 (6)	C10—C11—C12—N2	−44.3 (3)
C2—C3—C4—C5	−0.4 (6)	C14—C13—N2—C12	−50.4 (4)
C3—C4—C5—C6	−0.2 (5)	C14—C13—N2—C15	−173.1 (3)
C4—C5—C6—C1	0.2 (5)	N2—C13—C14—S1	−157.9 (2)
C4—C5—C6—C7	178.6 (3)	N2—C13—C14—C10	17.1 (4)
C5—C6—C1—O1	−179.1 (3)	S1—C14—C10—C9	−1.1 (4)
C5—C6—C1—C2	0.4 (5)	S1—C14—C10—C11	177.9 (2)
C7—C6—C1—O1	2.5 (5)	C13—C14—C10—C9	−176.5 (3)
C7—C6—C1—C2	−178.0 (3)	C13—C14—C10—C11	2.4 (5)
C6—C7—N1—C8	178.0 (3)	O3—C16—O2A—O2B	−76 (4)
N1—C7—C6—C1	0.9 (5)	C9—C16—O2A—O2B	113 (3)
N1—C7—C6—C5	−177.5 (3)	O3—C16—O2B—O2A	120 (3)
S1—C8—C9—C10	−2.1 (3)	C9—C16—O2B—O2A	−89 (4)
S1—C8—C9—C16	−179.1 (3)	O2A—C16—O3—C17	10.0 (9)
N1—C8—C9—C10	175.0 (3)	O2B—C16—O3—C17	−23.2 (16)
N1—C8—C9—C16	−2.0 (5)	C9—C16—O3—C17	−178.6 (4)
C8—C9—C10—C11	−176.8 (3)

D—H···A	D—H	H···A	D···A	D—H···A
O1—H1···O3	0.90 (5)	2.40 (5)	3.053 (4)	129 (4)
O1—H1···N1	0.90 (5)	1.79 (5)	2.605 (4)	148 (4)
C12—H12A···Cg1i	0.97	2.77	3.701 (3)	161

Table 1

Hydrogen-bond geometry (Å, °)

Cg1 is the centroid of ring B (S1/C8–C10/C14).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯O3	0.90 (5)	2.40 (5)	3.053 (4)	129 (4)
O1—H1⋯N1	0.90 (5)	1.79 (5)	2.605 (4)	148 (4)
C12—H12A⋯Cg1i	0.97	2.77	3.701 (3)	161

Symmetry code: (i) .