tert-Butyl N-(thio­phen-2-yl)carbamate

Hsu, G.C.; Singer, L.M.; Cordes, D.B.; Findlater, M.

doi:10.1107/S160053681302196X

organic compounds

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Volume 69| Part 9| September 2013| Page o1413

doi:10.1107/S160053681302196X

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tert-Butyl N-(thiophen-2-yl)carbamate

Gene C. Hsu,^a Laci M. Singer,^a David B. Cordes ^a and Michael Findlater ^a ^*

^aDepartment of Chemistry & Biochemistry, Texas Tech University, Memorial Circle & Boston, Lubbock, TX 79409, USA
^*Correspondence e-mail: michael.findlater@ttu.edu

(Received 26 July 2013; accepted 6 August 2013; online 14 August 2013)

In the title compound, C₉H₁₃NO₂S, the dihedral angle between the thiophene ring and the carbamate group is 15.79 (14)°. In the crystal structure, intramolecular C—H⋯O interactions in tandem with the tert-butyl groups render the packing of adjacent molecules in the [001] direction nearly perpendicular [the angle between adjacent thiophene rings is 74.83 (7)°]. An intermolecular N—H⋯O hydrogen bond gives rise to a chain extending along [001]. The crystal studied was found to be a racemic twin.

Related literature

For the synthesis of the title compound, see: Binder et al. (1977 ); Kruse et al. (1989 ). For related structures, see: Arsenyan et al. (2008 ); Elshaarawy & Janiak (2011 ); Low et al. (2009 ); Hsu et al. (2013 ).

Experimental

Crystal data

C₉H₁₃NO₂S
M_r = 199.26
Orthorhombic, P c a 2₁
a = 11.732 (2) Å
b = 8.6513 (17) Å
c = 9.879 (2) Å
V = 1002.7 (3) Å³
Z = 4
Mo Kα radiation
μ = 0.29 mm⁻¹
T = 153 K
0.20 × 0.10 × 0.08 mm

Data collection

Nonius KappaCCD diffractometer
Absorption correction: multi-scan (DENZO and SCALEPACK; Otwinowski & Minor, 1997 ) T_min = 0.944, T_max = 0.977
2112 measured reflections
2112 independent reflections
1816 reflections with I > 2σ(I)

Refinement

R[F² > 2σ(F²)] = 0.034
wR(F²) = 0.078
S = 1.04
2112 reflections
125 parameters
2 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.25 e Å⁻³
Δρ_min = −0.19 e Å⁻³
Absolute structure: Flack x determined using 703 quotients [(I⁺)−(I⁻)]/[(I⁺)+(I⁻)] (Parsons & Flack, 2004 )
Absolute structure parameter: 0.53 (4)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1N⋯O1ⁱ	0.90 (2)	2.04 (2)	2.920 (3)	165 (3)
C7—H7A⋯O1	0.98	2.33	2.938 (4)	119
C8—H8C⋯O1	0.98	2.55	3.109 (4)	116
Symmetry code: (i) $[-x+{\script{1\over 2}}, y, z+{\script{1\over 2}}]$ .

Data collection: COLLECT (Nonius, 1998 ); cell refinement: COLLECT; data reduction: DENZO and SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR97 (Altomare et al., 1999 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL, enCIFer (Allen et al., 2004 ) and publCIF (Westrip, 2010 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053681302196X/zs2273sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S160053681302196X/zs2273Isup2.hkl

Supporting information file. DOI: 10.1107/S160053681302196X/zs2273Isup3.cml

checkCIF report

Comment top

The title compound tert-butyl N-(thiophene-2-yl)carbamate, C₉H₁₃NO₂S, (Fig. 1) is a precursor in the synthesis of diimine ligands suitable for metal complex formation. This compound exhibits intramolecular methyl C7—H···O1 and C8—H···O1 interactions [2.938 (4) and 3.109 (4), respectively] in addition to bulky tert -butyl groups. These two features in tandem allow the packing in the crystal to be nearly perpendicular [the angle between adjacent thiophene rings = 74.83 (7)°]. An intermolecular N1—H···O1ⁱ hydrogen bond (Table 1) gives a one-dimensional chain which extends along [0 0 1]. The compound was synthesized via a typical Curtius Rearrangement from thiophene-2-carbonyl azide (Binder et al., 1977; Kruse et al., 1989).

Related literature top

For the synthesis of the title compound, see: Binder et al. (1977); Kruse et al. (1989). For related structures, see: Arsenyan et al. (2008); Elshaarawy & Janiak (2011); Low et al. (2009); Hsu et al. (2013).

Experimental top

The title compound was prepared by a typical Curtius Rearrangement. Thiophene-2-carbonyl azide (270 mg; 1.77 mmol) was reacted with 1.0 equivalent of tert-butyl alcohol (131 mg; 1.77 mmol) and dissolved in 15 ml of toluene. The solution was heated at 100 °C overnight. Excess solvent and tert-butyl alcohol was removed in vacuo. Crystals suitable for X-ray structure determination were obtained by cooling a toluene solution to -30 °C. ¹H NMR (400 MHz, chloroform-d): δ=6.9(br, 1H, –NH), 6.79(m, 2H, –CH), 6.5(dd, 1H, –CH), 1.5(s, 9H, tBu).

Computing details top

Data collection: COLLECT (Nonius, 1998); cell refinement: COLLECT (Nonius, 1998); data reduction: DENZO and SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR97 (Altomare et al., 1999); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008), enCIFer (Allen et al., 2004) and publCIF (Westrip, 2010).

Figures top

Fig. 1. The molecular structure of the title compound with displacement ellipsoids drawn at the 50% probability level.

tert-Butyl N-(thiophen-2-yl)carbamate top

Crystal data top

C₉H₁₃NO₂S	D_x = 1.320 Mg m⁻³
M_r = 199.26	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pca2₁	Cell parameters from 1327 reflections
a = 11.732 (2) Å	θ = 1.0–27.5°
b = 8.6513 (17) Å	µ = 0.29 mm⁻¹
c = 9.879 (2) Å	T = 153 K
V = 1002.7 (3) Å³	Rod, colorless
Z = 4	0.20 × 0.10 × 0.08 mm
F(000) = 424

Data collection top

Nonius KappaCCD diffractometer	2112 independent reflections
Radiation source: fine-focus sealed tube	1816 reflections with I > 2σ(I)
ϕ and ω scans	θ_max = 27.5°, θ_min = 2.4°
Absorption correction: multi-scan (DENZO and SCALEPACK; Otwinowski & Minor, 1997)	h = −15→15
T_min = 0.944, T_max = 0.977	k = −11→11
2112 measured reflections	l = −12→12

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: mixed
R[F² > 2σ(F²)] = 0.034	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.078	w = 1/[σ²(F_o²) + (0.0301P)² + 0.2397P] where P = (F_o² + 2F_c²)/3
S = 1.04	(Δ/σ)_max < 0.001
2112 reflections	Δρ_max = 0.25 e Å⁻³
125 parameters	Δρ_min = −0.19 e Å⁻³
2 restraints	Absolute structure: Flack x determined using 703 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons & Flack, 2004).
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.53 (4)

Crystal data top

C₉H₁₃NO₂S	V = 1002.7 (3) Å³
M_r = 199.26	Z = 4
Orthorhombic, Pca2₁	Mo Kα radiation
a = 11.732 (2) Å	µ = 0.29 mm⁻¹
b = 8.6513 (17) Å	T = 153 K
c = 9.879 (2) Å	0.20 × 0.10 × 0.08 mm

Data collection top

Nonius KappaCCD diffractometer	2112 measured reflections
Absorption correction: multi-scan (DENZO and SCALEPACK; Otwinowski & Minor, 1997)	2112 independent reflections
T_min = 0.944, T_max = 0.977	1816 reflections with I > 2σ(I)

Refinement top

R[F² > 2σ(F²)] = 0.034	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.078	Δρ_max = 0.25 e Å⁻³
S = 1.04	Δρ_min = −0.19 e Å⁻³
2112 reflections	Absolute structure: Flack x determined using 703 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons & Flack, 2004).
125 parameters	Absolute structure parameter: 0.53 (4)
2 restraints

Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
S1	0.13622 (6)	0.05380 (7)	0.63359 (7)	0.02745 (19)
O1	0.29399 (16)	0.2992 (2)	0.61913 (19)	0.0273 (4)
O2	0.32467 (18)	0.4564 (2)	0.80079 (18)	0.0289 (5)
N1	0.23352 (19)	0.2367 (2)	0.8305 (2)	0.0224 (5)
H1N	0.238 (3)	0.264 (4)	0.919 (2)	0.036 (9)*
C1	0.1713 (2)	0.1041 (3)	0.7987 (3)	0.0209 (5)
C2	0.1219 (3)	0.0067 (3)	0.8902 (3)	0.0241 (6)
H2	0.1317	0.0150	0.9854	0.029*
C3	0.0542 (2)	−0.1082 (3)	0.8269 (3)	0.0289 (6)
H3	0.0137	−0.1855	0.8754	0.035*
C4	0.0533 (3)	−0.0964 (3)	0.6907 (3)	0.0306 (7)
H4	0.0115	−0.1635	0.6329	0.037*
C5	0.2857 (2)	0.3295 (3)	0.7389 (3)	0.0220 (6)
C6	0.3798 (2)	0.5829 (3)	0.7233 (3)	0.0250 (6)
C7	0.3034 (3)	0.6385 (4)	0.6108 (4)	0.0438 (9)
H7A	0.2928	0.5554	0.5446	0.066*
H7B	0.3384	0.7280	0.5663	0.066*
H7C	0.2292	0.6684	0.6483	0.066*
C8	0.4940 (3)	0.5271 (4)	0.6722 (4)	0.0445 (9)
H8A	0.5384	0.4856	0.7480	0.067*
H8B	0.5354	0.6135	0.6310	0.067*
H8C	0.4823	0.4458	0.6045	0.067*
C9	0.3945 (3)	0.7083 (3)	0.8284 (4)	0.0459 (9)
H9A	0.3196	0.7408	0.8617	0.069*
H9B	0.4337	0.7970	0.7878	0.069*
H9C	0.4399	0.6685	0.9040	0.069*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
S1	0.0369 (4)	0.0261 (3)	0.0194 (3)	−0.0050 (3)	0.0003 (3)	−0.0034 (3)
O1	0.0377 (11)	0.0268 (9)	0.0173 (10)	−0.0043 (8)	0.0014 (9)	−0.0012 (8)
O2	0.0425 (12)	0.0258 (10)	0.0182 (9)	−0.0120 (8)	0.0029 (9)	0.0003 (8)
N1	0.0293 (13)	0.0232 (11)	0.0147 (9)	−0.0051 (9)	0.0006 (10)	−0.0009 (10)
C1	0.0234 (13)	0.0211 (12)	0.0183 (12)	0.0033 (11)	0.0000 (11)	−0.0012 (11)
C2	0.0277 (16)	0.0226 (13)	0.0221 (13)	0.0002 (11)	−0.0017 (11)	0.0006 (11)
C3	0.0300 (16)	0.0227 (14)	0.0340 (15)	−0.0037 (12)	−0.0002 (13)	0.0029 (13)
C4	0.0329 (18)	0.0259 (15)	0.0330 (15)	−0.0030 (12)	−0.0029 (14)	−0.0039 (13)
C5	0.0238 (15)	0.0227 (14)	0.0195 (15)	0.0016 (11)	−0.0023 (11)	−0.0005 (11)
C6	0.0288 (17)	0.0228 (14)	0.0234 (13)	−0.0047 (12)	0.0053 (11)	0.0019 (11)
C7	0.0453 (19)	0.0306 (15)	0.056 (2)	−0.0046 (14)	−0.0128 (18)	0.0135 (16)
C8	0.0299 (17)	0.0339 (16)	0.070 (2)	−0.0022 (13)	0.0128 (18)	0.0021 (16)
C9	0.070 (2)	0.0327 (17)	0.0347 (17)	−0.0212 (17)	0.0122 (17)	−0.0068 (15)

Geometric parameters (Å, º) top

S1—C4	1.718 (3)	C4—H4	0.9500
S1—C1	1.737 (3)	C6—C7	1.507 (4)
O1—C5	1.216 (3)	C6—C8	1.511 (4)
O2—C5	1.337 (3)	C6—C9	1.512 (4)
O2—C6	1.484 (3)	C7—H7A	0.9800
N1—C5	1.356 (3)	C7—H7B	0.9800
N1—C1	1.396 (3)	C7—H7C	0.9800
N1—H1N	0.90 (2)	C8—H8A	0.9800
C1—C2	1.365 (4)	C8—H8B	0.9800
C2—C3	1.418 (4)	C8—H8C	0.9800
C2—H2	0.9500	C9—H9A	0.9800
C3—C4	1.350 (4)	C9—H9B	0.9800
C3—H3	0.9500	C9—H9C	0.9800

C4—S1—C1	90.88 (14)	C7—C6—C8	112.6 (3)
C5—O2—C6	121.3 (2)	O2—C6—C9	103.0 (2)
C5—N1—C1	124.9 (2)	C7—C6—C9	110.2 (3)
C5—N1—H1N	117 (2)	C8—C6—C9	111.0 (3)
C1—N1—H1N	118 (2)	C6—C7—H7A	109.5
C2—C1—N1	125.4 (2)	C6—C7—H7B	109.5
C2—C1—S1	111.5 (2)	H7A—C7—H7B	109.5
N1—C1—S1	122.77 (19)	C6—C7—H7C	109.5
C1—C2—C3	112.2 (3)	H7A—C7—H7C	109.5
C1—C2—H2	123.9	H7B—C7—H7C	109.5
C3—C2—H2	123.9	C6—C8—H8A	109.5
C4—C3—C2	113.0 (3)	C6—C8—H8B	109.5
C4—C3—H3	123.5	H8A—C8—H8B	109.5
C2—C3—H3	123.5	C6—C8—H8C	109.5
C3—C4—S1	112.3 (2)	H8A—C8—H8C	109.5
C3—C4—H4	123.8	H8B—C8—H8C	109.5
S1—C4—H4	123.8	C6—C9—H9A	109.5
O1—C5—O2	126.4 (2)	C6—C9—H9B	109.5
O1—C5—N1	123.9 (2)	H9A—C9—H9B	109.5
O2—C5—N1	109.6 (2)	C6—C9—H9C	109.5
O2—C6—C7	110.9 (2)	H9A—C9—H9C	109.5
O2—C6—C8	108.8 (2)	H9B—C9—H9C	109.5

C5—N1—C1—C2	177.5 (3)	C1—S1—C4—C3	−0.9 (3)
C5—N1—C1—S1	−8.9 (4)	C6—O2—C5—O1	3.3 (4)
C4—S1—C1—C2	0.9 (2)	C6—O2—C5—N1	−176.4 (2)
C4—S1—C1—N1	−173.5 (2)	C1—N1—C5—O1	−7.8 (4)
N1—C1—C2—C3	173.6 (2)	C1—N1—C5—O2	171.9 (2)
S1—C1—C2—C3	−0.7 (3)	C5—O2—C6—C7	54.5 (3)
C1—C2—C3—C4	0.0 (4)	C5—O2—C6—C8	−69.8 (3)
C2—C3—C4—S1	0.7 (4)	C5—O2—C6—C9	172.4 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O1ⁱ	0.90 (2)	2.04 (2)	2.920 (3)	165 (3)
C7—H7A···O1	0.98	2.33	2.938 (4)	119
C8—H8C···O1	0.98	2.55	3.109 (4)	116

Symmetry code: (i) −x+1/2, y, z+1/2.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1N···O1ⁱ	0.90 (2)	2.04 (2)	2.920 (3)	165 (3)
C7—H7A···O1	0.98	2.33	2.938 (4)	119.0
C8—H8C···O1	0.98	2.55	3.109 (4)	116.0

Symmetry code: (i) −x+1/2, y, z+1/2.

Acknowledgements

The authors gratefully acknowledge the Robert A. Welch Foundation for their support of GCH via the Welch Summer Scholars Program, and Texas Tech University for start-up funds.

References

Allen, F. H., Johnson, O., Shields, G. P., Smith, B. R. & Towler, M. (2004). J. Appl. Cryst. 37, 335–338. Web of Science CrossRef CAS IUCr Journals Google Scholar
Altomare, A., Burla, M. C., Camalli, M., Cascarano, G. L., Giacovazzo, C., Guagliardi, A., Moliterni, A. G. G., Polidori, G. & Spagna, R. (1999). J. Appl. Cryst. 32, 115–119. Web of Science CrossRef CAS IUCr Journals Google Scholar
Arsenyan, P., Petrenko, A. & Belyakov, S. (2008). Tetrahedron Lett. 49, 5255–5257. Web of Science CSD CrossRef CAS Google Scholar
Binder, D., Habison, G. & Noe, C. R. (1977). Synthesis, pp. 255–256. CrossRef Google Scholar
Elshaarawy, R. F. & Janiak, C. (2011). Z. Naturforsch. Teil B, 66, 1201–1208. Google Scholar
Hsu, G. C., Singer, L. M., Cordes, D. B. & Findlater, M. (2013). Acta Cryst. E69, o1298. CSD CrossRef IUCr Journals Google Scholar
Kruse, L. I., Ladd, D. L., Harrsch, P. B., McCabe, F. L., Mong, S.-M., Faucette, L. & Johnson, R. (1989). J. Med. Chem. 32, 409–417. CrossRef CAS PubMed Web of Science Google Scholar
Low, J. N., Quesada, A., Santos, L. M. N. B. F., Schröder, B. & Gomes, L. R. (2009). J. Chem. Crystallogr. 39, 747–752. Web of Science CSD CrossRef CAS Google Scholar
Nonius (1998). COLLECT. Nonius BV, Delft, The Netherlands. Google Scholar
Otwinowski, Z. & Minor, W. (1997). Methods in Enzymology, Vol. 276, Macromolecular Crystallography, Part A, edited by C. W. Carter Jr & R. M. Sweet, pp. 307–326. New York: Academic Press. Google Scholar
Parsons, S. & Flack, H. (2004). Acta Cryst. A60, s61. CrossRef IUCr Journals Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920–925. Web of Science CrossRef CAS IUCr Journals Google Scholar