Methyl (E)-3-acet­amido-2-butenoate

The crystal structure determination of the title compound, C₇H₁₁NO₃, shows that it is the E isomer. An N—H...O intermolecular hydrogen bond is observed. The mol­ecules are linked along [101] through this intermolecular hydrogen bond.

Key indicators

• Single-crystal X-ray study
• T = 294 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.051
• wR factor = 0.148
• Data-to-parameter ratio = 18.9

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry

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S1. Comment

The title compound, (I), is one of the isomers of methyl 3-acetamido-2-butenoate, a prochiral olefinic substrate for producing β-amino acids and derivatives by asymmetric hydrogenation (Hackler et al., 1985; Lubell et al., 1991). The E isomer gives a much higher enantiomeric excess than the Z isomer in the asymmetric hydrogenation reaction (Burk et al., 1996). The structure determination of (I) was conducted in order to obtain more knowledge about β-amino acids and their derivatives.

Fig. 1 shows a perspective view of the molecule. The deviations of the angles C4—C3—C7 [126.40 (17)°], C3—C4—C5 [124.88 (17)°] and N1—C3—C7 [110.64 (15)°] from the value of 120° results in a close approach between the methyl group on C3 and the carbonyl group on C4 (Table 1). The molecules are connected through an intermolecular hydrogen bond (Table 2). In the packing, the molecules are connected by an N—H···O hydrogen bond and linking along [101] (Fig. 2).

S2. Experimental

The title compound was synthesized according to the literature (Zhu et al., 1999). A crystal suitable for X-ray analysis was slowly grown in a mixed solvent of ethyl acetate and hexane (EA/nexane 1:6) at room temperature. ¹H NMR (400 MHz, acetone-d₆, p.p.m.): δ 2.03 (s, 3H), 2.29 (s, 3H), 3.58 (s, 3H), 6.85 (d, J = 1 Hz, 1H), 8.79 (br, 1H).

S3. Refinement

H atoms were included in the riding-model approximation with U_iso values equal to U_eq of the atom to which they were bound.

Computing details

Data collection: SMART (Siemens, 1995); cell refinement: SMART; data reduction: SHELXTL-NT (Siemens, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL-NT; software used to prepare material for publication: SHELXTL-NT.

Figures

	Fig. 1. The molecular structure of (I), showing ellipsoids at the 30% probability level (Siemens, 1995).
	Fig. 2. Packing diagram for the title compound. Hydrogen bonds are shown as dotted lines.

(E)-Methyl 3-acetamido-2-butenoate

Crystal data

C7H11NO3	F(000) = 336
Mr = 157.17	Dx = 1.231 Mg m^−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
a = 8.099 (2) Å	Cell parameters from 1994 reflections
b = 12.761 (2) Å	θ = 1–27.5°
c = 8.750 (2) Å	µ = 0.10 mm^−1
β = 110.268 (4)°	T = 294 K
V = 848.4 (2) Å^3	Prism, colorless
Z = 4	0.36 × 0.32 × 0.30 mm

Data collection

Siemens SMART CCD area-detector diffractometer	1945 independent reflections
Radiation source: fine-focus sealed tube	994 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.038
ϕ and ω scans	θmax = 27.5°, θmin = 3.0°
Absorption correction: empirical (using intensity measurements) (SADABS; Sheldrick, 1996)	h = −10→9
Tmin = 0.966, Tmax = 0.972	k = −14→16
5609 measured reflections	l = −7→11

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)] = 0.051	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.148	H-atom parameters constrained
S = 1.01	w = 1/[σ^2(Fo^2) + (0.07P)^2] where P = (Fo^2 + 2Fc^2)/3
1945 reflections	(Δ/σ)max < 0.001
103 parameters	Δρmax = 0.17 e Å^−3
0 restraints	Δρmin = −0.15 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
O1	−0.09296 (17)	0.26580 (10)	0.29159 (17)	0.0679 (5)
O3	−0.05051 (19)	0.59645 (11)	0.12587 (18)	0.0733 (5)
O2	0.2126 (3)	0.62923 (12)	0.3063 (2)	0.1145 (8)
N1	0.14590 (18)	0.32240 (11)	0.49975 (18)	0.0516 (5)
H1A	0.2193	0.3032	0.5926	0.062*
C4	0.0713 (2)	0.46541 (13)	0.3085 (2)	0.0533 (5)
H4	−0.0168	0.4234	0.2391	0.064*
C3	0.1702 (2)	0.42467 (14)	0.4509 (2)	0.0474 (5)
C5	0.0906 (3)	0.57061 (15)	0.2534 (3)	0.0599 (6)
C2	0.0234 (2)	0.24983 (14)	0.4215 (2)	0.0547 (5)
C7	0.3149 (3)	0.47864 (16)	0.5809 (3)	0.0700 (7)
H7A	0.3282	0.5486	0.5463	0.105*
H7B	0.4228	0.4407	0.6013	0.105*
H7C	0.2871	0.4815	0.6789	0.105*
C1	0.0434 (3)	0.14619 (15)	0.5063 (3)	0.0801 (8)
H1B	−0.0708	0.1168	0.4889	0.120*
H1C	0.1043	0.1558	0.6209	0.120*
H1D	0.1095	0.0995	0.4634	0.120*
C6	−0.0507 (4)	0.69941 (18)	0.0564 (3)	0.0899 (8)
H6A	−0.0571	0.7519	0.1328	0.135*
H6B	−0.1506	0.7059	−0.0421	0.135*
H6C	0.0555	0.7087	0.0325	0.135*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
O1	0.0695 (9)	0.0526 (8)	0.0540 (9)	−0.0127 (6)	−0.0139 (7)	0.0065 (6)
O3	0.0782 (10)	0.0568 (9)	0.0756 (10)	0.0102 (7)	0.0151 (8)	0.0231 (7)
O2	0.1207 (14)	0.0722 (11)	0.1106 (16)	−0.0385 (11)	−0.0109 (12)	0.0223 (10)
N1	0.0541 (9)	0.0419 (9)	0.0424 (9)	−0.0005 (7)	−0.0043 (7)	0.0000 (7)
C4	0.0584 (11)	0.0400 (10)	0.0519 (12)	−0.0035 (9)	0.0070 (9)	−0.0023 (9)
C3	0.0464 (10)	0.0415 (10)	0.0486 (11)	0.0006 (8)	0.0093 (9)	−0.0035 (8)
C5	0.0692 (13)	0.0455 (11)	0.0579 (13)	0.0008 (10)	0.0131 (11)	0.0001 (10)
C2	0.0570 (12)	0.0461 (11)	0.0483 (12)	−0.0005 (9)	0.0022 (10)	0.0020 (9)
C7	0.0639 (13)	0.0614 (13)	0.0670 (15)	−0.0114 (10)	0.0001 (11)	−0.0047 (11)
C1	0.0893 (16)	0.0497 (13)	0.0733 (16)	−0.0098 (11)	−0.0076 (13)	0.0115 (11)
C6	0.121 (2)	0.0606 (14)	0.0913 (19)	0.0254 (14)	0.0415 (17)	0.0321 (13)

Geometric parameters (Å, º)

O1—C2	1.216 (2)	C2—C1	1.498 (3)
O3—C5	1.333 (2)	C7—H7A	0.9600
O3—C6	1.447 (3)	C7—H7B	0.9600
O2—C5	1.197 (2)	C7—H7C	0.9600
N1—C2	1.357 (2)	C1—H1B	0.9600
N1—C3	1.408 (2)	C1—H1C	0.9600
N1—H1A	0.8600	C1—H1D	0.9600
C4—C3	1.332 (2)	C6—H6A	0.9600
C4—C5	1.453 (3)	C6—H6B	0.9600
C4—H4	0.9300	C6—H6C	0.9600
C3—C7	1.489 (2)
C5—O3—C6	116.86 (17)	C3—C7—H7B	109.5
C2—N1—C3	129.36 (15)	H7A—C7—H7B	109.5
C2—N1—H1A	115.3	C3—C7—H7C	109.5
C3—N1—H1A	115.3	H7A—C7—H7C	109.5
C3—C4—C5	124.88 (17)	H7B—C7—H7C	109.5
C3—C4—H4	117.6	C2—C1—H1B	109.5
C5—C4—H4	117.6	C2—C1—H1C	109.5
C4—C3—N1	122.94 (15)	H1B—C1—H1C	109.5
C4—C3—C7	126.40 (17)	C2—C1—H1D	109.5
N1—C3—C7	110.64 (15)	H1B—C1—H1D	109.5
O2—C5—O3	121.52 (19)	H1C—C1—H1D	109.5
O2—C5—C4	128.2 (2)	O3—C6—H6A	109.5
O3—C5—C4	110.27 (17)	O3—C6—H6B	109.5
O1—C2—N1	123.49 (17)	H6A—C6—H6B	109.5
O1—C2—C1	121.80 (17)	O3—C6—H6C	109.5
N1—C2—C1	114.70 (16)	H6A—C6—H6C	109.5
C3—C7—H7A	109.5	H6B—C6—H6C	109.5
C5—C4—C3—N1	179.54 (18)	C6—O3—C5—C4	−179.80 (19)
C5—C4—C3—C7	1.4 (3)	C3—C4—C5—O2	15.9 (4)
C2—N1—C3—C4	−2.1 (3)	C3—C4—C5—O3	−165.59 (19)
C2—N1—C3—C7	176.35 (19)	C3—N1—C2—O1	−2.3 (3)
C6—O3—C5—O2	−1.2 (3)	C3—N1—C2—C1	176.73 (18)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N1—H1A···O1^i	0.86	2.07	2.9188 (19)	169

Symmetry code: (i) x+1/2, −y+1/2, z+1/2.