O-Iso­propyl N-(2-furoyl)­thio­car­bam­ate

The title compound, C₉H₁₁NO₃S, has crystallographic mirror symmetry, occurs in the thio­carbamate form and is stabilized in an s-cisoid,s-transoid conformation with respect to the C-N-C group. There are two intramolecular hydrogen bonds, one between the H atom of the N-H group and the O atom of the furan ring, and the other between the H atom of the secondary carbon of the iso­propyl group and the S atom. The packing of the mol­ecules is assumed to be dictated by van der Waals interactions.

S1. Comment

The chemistry of organic sulfur compounds, such as thiocarbamates and their S-alkylated products, has been investigated with increasing interest due to the biological activity of these compounds (Schröpl & Pohloudek-Fabini, 1968). In recent years, O-alkyl N-acylthiocarbamates have been proposed as intermediates for regio- and chemoselective deoxygenation for primary and secondary aliphatic alcohols (Oba & Nishiyama, 1994). Structural studies of O-alkyl N-benzoylthiocarbamate showed the C—N bonds to have partial double-bond character, thus giving rise to hindered rotation (Schröder et al., 1995). The present paper reports the crystal structure of O-isopropyl N-(2-furoyl)thiocarbamate, (I), in order to provide a better understanding of the above-mentioned properties.

The title compound crystallizes in the thiocarbamate form. A view of the molecule with the atom-numbering scheme is shown in Fig. 1. The asymmetry of the C3—C4—C5 and O1—C4—C5 angles [131.8 (5) and 118.9 (4)°, respectively] is probably caused by repulsion in the C3—H3···O2 system [C3···O2 = 3.006 (6) and H3···O2 = 2.96 Å] and attraction in the N—H···O1 system (see Table 2). The molecule is stabilized in the s-cisoid,s-transoid conformation with respect to the C5—N1—C6 group. The bond distance C6—O3 indiactes double-bond character, while the C5—N1 and C6—N1 distances indicate C_sp2—N_sp2 single-bond character. This indicates that there is π–π conjugation along S1—C6—O3, but not along O2—C5—N1 and N1—C6—S1 as reported for O-alkyl N-benzoylthiocarbamate (Schröder et al., 1995).

There are two intramolecular hydrogen bonds, one between the N—H group and the O atom of the furan ring, and the other between the H atom of the secondary carbon of the isopropyl group and the S atom. The packing of the molecules is assumed to be dictated by short contacts and van der Waals interactions.

S2. Experimental

The title compound was synthesized by the reaction of furoyl isothiocyanate with isopropyl alcohol using acetone as solvent (Schröder et al., 1995). Recrystallization from methanol gave crystals suitable for X-ray analysis.

S3. Refinement

H atoms were calculated geometrically and included in the refinement, but were restrained to ride on their parent atoms. The isotropic displacement parameters of the H atoms were fixed to 1.3U_eq of their parent atoms.

Computing details

Data collection: DIF4 (Stoe & Cie, 1992); cell refinement: DIF4; data reduction: REDU4 (Stoe & Cie, 1992); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: DIAMOND (Bergerhoff, 1996); software used to prepare material for publication: SHELXL97 (Sheldrick 1997) and PARST (Nardelli, 1983, 1995).

Figures

Fig. 1. Plot of (I) showing the atomic numbering scheme. Displacement ellipsoids are drawn at 50% probability level for non-H atoms. [Symmetry code: (i) x, 1/2 − y, z.]

O-Isopropyl N-(2-furoyl)thiocarbamate

Crystal data

C9H11NO3S	F(000) = 224
Mr = 213.25	Dx = 1.331 Mg m^−3
Monoclinic, P21/m	Mo Kα radiation, λ = 0.71073 Å
a = 7.679 (4) Å	Cell parameters from 25 reflections
b = 7.004 (5) Å	θ = 10–15°
c = 10.372 (5) Å	µ = 0.29 mm^−1
β = 107.43 (4)°	T = 293 K
V = 532.2 (5) Å^3	Prism, colourless
Z = 2	0.6 × 0.2 × 0.1 mm

Data collection

Stoe Stadi-4 four-circle diffractometer	Rint = 0.058
Radiation source: fine-focus sealed tube	θmax = 25.0°, θmin = 2.1°
Graphite monochromator	h = −2→9
ω scans	k = −2→8
1980 measured reflections	l = −12→12
1019 independent reflections	2 standard reflections every 60 min
457 reflections with I > 2σ(I)	intensity decay: <2.0%

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.055	H-atom parameters constrained
wR(F^2) = 0.134	w = 1/[σ^2(Fo^2) + (0.0545P)^2 + 0.0084P] where P = (Fo^2 + 2Fc^2)/3
S = 0.98	(Δ/σ)max < 0.001
1019 reflections	Δρmax = 0.19 e Å^−3
84 parameters	Δρmin = −0.19 e Å^−3
0 restraints	Extinction correction: SHELXL97, Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.038 (7)

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	0.3128 (2)	0.2500	0.91368 (13)	0.0848 (8)
O1	−0.1571 (5)	0.2500	0.4904 (3)	0.0656 (13)
O2	0.2914 (5)	0.2500	0.4666 (3)	0.0947 (19)
O3	0.4864 (5)	0.2500	0.7292 (3)	0.0827 (17)
N1	0.1849 (5)	0.2500	0.6505 (4)	0.0590 (15)
H1	0.0830	0.2500	0.6690	0.071*
C1	−0.3197 (7)	0.2500	0.3881 (6)	0.076 (2)
H1A	−0.4345	0.2500	0.4011	0.091*
C2	−0.2903 (7)	0.2500	0.2686 (6)	0.070 (2)
H2	−0.3784	0.2500	0.1844	0.084*
C3	−0.1005 (7)	0.2500	0.2938 (5)	0.0659 (19)
H3	−0.0387	0.2500	0.2291	0.079*
C4	−0.0237 (7)	0.2500	0.4294 (5)	0.0551 (18)
C5	0.1670 (8)	0.2500	0.5134 (5)	0.0588 (18)
C6	0.3373 (7)	0.2500	0.7623 (5)	0.0537 (18)
C7	0.6648 (7)	0.2500	0.8351 (6)	0.096 (3)
H7	0.6499	0.2500	0.9257	0.116*
C8	0.7613 (6)	0.4272 (9)	0.8109 (5)	0.123 (3)
H8A	0.7647	0.4285	0.7192	0.185*
H8B	0.8837	0.4283	0.8712	0.185*
H8C	0.6972	0.5380	0.8271	0.185*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.0516 (10)	0.155 (2)	0.0464 (8)	0.000	0.0131 (7)	0.000
O1	0.035 (2)	0.107 (4)	0.053 (2)	0.000	0.0114 (19)	0.000
O2	0.036 (2)	0.199 (6)	0.050 (2)	0.000	0.0134 (19)	0.000
O3	0.033 (2)	0.167 (5)	0.0436 (19)	0.000	0.0048 (17)	0.000
N1	0.030 (2)	0.100 (5)	0.045 (2)	0.000	0.008 (2)	0.000
C1	0.032 (3)	0.113 (7)	0.075 (4)	0.000	0.006 (3)	0.000
C2	0.045 (4)	0.096 (7)	0.056 (3)	0.000	−0.005 (3)	0.000
C3	0.044 (4)	0.100 (6)	0.051 (3)	0.000	0.010 (3)	0.000
C4	0.034 (3)	0.087 (6)	0.044 (3)	0.000	0.010 (2)	0.000
C5	0.047 (4)	0.082 (6)	0.048 (3)	0.000	0.016 (3)	0.000
C6	0.035 (3)	0.071 (6)	0.054 (3)	0.000	0.012 (3)	0.000
C7	0.034 (4)	0.202 (11)	0.052 (3)	0.000	0.011 (3)	0.000
C8	0.055 (3)	0.152 (7)	0.140 (5)	0.004 (4)	−0.007 (3)	−0.056 (5)

Geometric parameters (Å, º)

S1—C6	1.636 (5)	C2—C3	1.402 (7)
O1—C4	1.356 (6)	C2—H2	0.93
O1—C1	1.375 (6)	C3—C4	1.352 (7)
O2—C5	1.194 (6)	C3—H3	0.93
O3—C6	1.290 (6)	C4—C5	1.463 (7)
O3—C7	1.477 (6)	C7—C8^i	1.505 (6)
N1—C6	1.379 (6)	C7—C8	1.505 (6)
N1—C5	1.387 (6)	C7—H7	0.9800
N1—H1	0.86	C8—H8A	0.96
C1—C2	1.326 (7)	C8—H8B	0.96
C1—H1A	0.93	C8—H8C	0.96
C4—O1—C1	106.2 (4)	O2—C5—C4	122.5 (5)
C6—O3—C7	120.1 (4)	N1—C5—C4	112.6 (5)
C6—N1—C5	131.4 (4)	O3—C6—N1	111.9 (4)
C6—N1—H1	114.3	O3—C6—S1	128.4 (4)
C5—N1—H1	114.3	N1—C6—S1	119.7 (4)
C2—C1—O1	110.6 (5)	O3—C7—C8^i	105.6 (3)
C2—C1—H1A	124.7	O3—C7—C8	105.6 (3)
O1—C1—H1A	124.7	C8^i—C7—C8	111.1 (6)
C1—C2—C3	106.5 (5)	O3—C7—H7	111.4
C1—C2—H2	126.7	C8^i—C7—H7	111.4
C3—C2—H2	126.7	C8—C7—H7	111.4
C4—C3—C2	107.4 (5)	C7—C8—H8A	109.5
C4—C3—H3	126.3	C7—C8—H8B	109.5
C2—C3—H3	126.3	H8A—C8—H8B	109.5
C3—C4—O1	109.3 (4)	C7—C8—H8C	109.5
C3—C4—C5	131.8 (5)	H8A—C8—H8C	109.5
O1—C4—C5	118.9 (4)	H8B—C8—H8C	109.5
O2—C5—N1	124.8 (5)
C4—O1—C1—C2	0	O1—C4—C5—O2	180
O1—C1—C2—C3	0	C3—C4—C5—N1	180
C1—C2—C3—C4	0	O1—C4—C5—N1	0
C2—C3—C4—O1	0	C7—O3—C6—N1	180
C2—C3—C4—C5	180	C7—O3—C6—S1	0
C1—O1—C4—C3	0	C5—N1—C6—O3	0
C1—O1—C4—C5	180	C5—N1—C6—S1	180
C6—N1—C5—O2	0	C6—O3—C7—C8^i	121.1 (3)
C6—N1—C5—C4	180	C6—O3—C7—C8	−121.1 (3)
C3—C4—C5—O2	0

Symmetry code: (i) x, −y+1/2, z.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1···O1	0.86	2.19	2.654 (6)	114
C1—H1A···O2^ii	0.93	2.40	3.322 (7)	172
C7—H7···S1	0.98	2.55	3.048 (7)	111

Symmetry code: (ii) x−1, y, z.