Buy article online - an online subscription or single-article purchase is required to access this article.
Download citation
Download citation
link to html
The title compound, C7H11NO4, is a useful precursor in the synthesis of substituted pyrimidine bases. It is prepared from diketene and urethane and can be isolated from benzene as colorless, transparent, plate crystals. The H atom of the secondary amide forms centrosymmetric planar dimers with the carbonyl group of a second symmetry-related mol­ecule. The ketone carbonyl of the β-keto amide is present as the keto tautomer and not as the enol. The r.m.s. deviation of the atoms in the hydrogen-bonded dimer from the least-squares plane defined by those atoms is 0.014 Å.

Supporting information

cif

Crystallographic Information File (CIF) https://doi.org/10.1107/S1600536802006797/om6087sup1.cif
Contains datablocks global, I

hkl

Structure factor file (CIF format) https://doi.org/10.1107/S1600536802006797/om6087Isup2.hkl
Contains datablock I

CCDC reference: 185796

Key indicators

  • Single-crystal X-ray study
  • T = 300 K
  • Mean [sigma](C-C) = 0.003 Å
  • R factor = 0.054
  • wR factor = 0.139
  • Data-to-parameter ratio = 17.8

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry








Comment top

The preparation of N-acetoacetylurethane, (I), was first described by Ralph et al. (1959) in pursuit of orotic acids. Dewar & Shaw (1961) subsequently reacted this compound with triethyl orthoformate to give 2-acetyl-3-ethoxy-N-ethoxycarbonylacrylamide which was then treated with ammonia to finally give 5-acetyluracil. While the crystal structure of several carbamates has been reported, the structure of this 3-ketoacyl carbamate has not been described.

N-Acetoacetylurethane is easily prepared from diketene and urethane in refluxing acetic acid. Unlike Ralph et al. (1959), who stated that the compound could be isolated from benzene as fine crystals, we found that slow recrystallization of the compound from several solvents, including benzene, afforded large planar crystals in the P21/n space group. The molecule of (I) and the associated numbering scheme are shown in Fig. 1.

In the crystal, the molecules are arranged as hydrogen-bonded dimers through the amide moiety of the acyl carbamate (Fig. 2). It is interesting that the molecule evidently adopts exclusively the keto rather than the enol form in the crystal, despite the fact that the latter would permit a substantial hydrogen-bonding network. All bond lengths are consistent with anticipated values.

Experimental top

The title compound was synthesized as described by Ralph et al. (1959). Recrystallization from benzene yielded colorless rectangular planar crystals with a melting point of 348–350 K suitable for X-ray analysis. The crystal used for the structure determination was trimmed from a larger crystal using a sharp scalpel. No correction for crystal decay during the data collection (7 h) was made.

Refinement top

H atoms on C atoms were constrained to ride on the parent atom with usual bond lengths. The H atomn on the amide N atom was not constrained in the refinement and the final N—H bond length was 0.85 (2) Å.

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SAINT-Plus (Bruker, 2001); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXTL-NT (Bruker, 2001); program(s) used to refine structure: SHELXTL-NT; molecular graphics: SHELXTL-NT; software used to prepare material for publication: SHELXTL-NT.

Figures top
[Figure 1] Fig. 1. A view of (I), with displacement ellipsoids shown at the 50% probability level.
[Figure 2] Fig. 2. A view of the hydrogen-bonded dimer in (I). Displacement ellipsoids are shown at the 50% probability level.
Ethyl N-(3-Oxobutanoyl)carbamate top
Crystal data top
C7H11NO4F(000) = 368
Mr = 173.17Dx = 1.335 Mg m3
Dm = 1.33 Mg m3
Dm measured by Flotation
Monoclinic, P21/nMelting point: 350 K
Hall symbol: -P 2ynMo Kα radiation, λ = 0.71073 Å
a = 11.366 (2) ÅCell parameters from 300 reflections
b = 5.7345 (13) Åθ = 2.2–24.5°
c = 13.327 (3) ŵ = 0.11 mm1
β = 97.388 (5)°T = 300 K
V = 861.4 (3) Å3Plate, colorless
Z = 40.40 × 0.35 × 0.15 mm
Data collection top
Bruker CCD area-detector
diffractometer
2044 independent reflections
Radiation source: fine-focus sealed tube1489 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.022
ϕ and ω scansθmax = 28.3°, θmin = 2.2°
Absorption correction: multi-scan
(SADABS; Bruker, 2001)
h = 1411
Tmin = 0.87, Tmax = 0.98k = 77
5292 measured reflectionsl = 1317
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.054Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.139H atoms treated by a mixture of independent and constrained refinement
S = 1.04 w = 1/[σ2(Fo2) + (0.061P)2 + 0.2379P]
where P = (Fo2 + 2Fc2)/3
2044 reflections(Δ/σ)max = 0.001
115 parametersΔρmax = 0.21 e Å3
0 restraintsΔρmin = 0.15 e Å3
Crystal data top
C7H11NO4V = 861.4 (3) Å3
Mr = 173.17Z = 4
Monoclinic, P21/nMo Kα radiation
a = 11.366 (2) ŵ = 0.11 mm1
b = 5.7345 (13) ÅT = 300 K
c = 13.327 (3) Å0.40 × 0.35 × 0.15 mm
β = 97.388 (5)°
Data collection top
Bruker CCD area-detector
diffractometer
2044 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2001)
1489 reflections with I > 2σ(I)
Tmin = 0.87, Tmax = 0.98Rint = 0.022
5292 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0540 restraints
wR(F2) = 0.139H atoms treated by a mixture of independent and constrained refinement
S = 1.04Δρmax = 0.21 e Å3
2044 reflectionsΔρmin = 0.15 e Å3
115 parameters
Special details top

Geometry. All e.s.d.'s 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 (Å2) top
xyzUiso*/Ueq
O10.01782 (11)0.2523 (2)1.07166 (11)0.0488 (4)
O30.31358 (13)0.2499 (3)1.19422 (12)0.0578 (4)
O50.34333 (12)0.2470 (2)0.96508 (11)0.0537 (4)
O60.27470 (11)0.0992 (2)0.90452 (11)0.0533 (4)
N10.15821 (13)0.1108 (3)0.98660 (12)0.0403 (4)
H10.1097 (17)0.001 (4)0.9693 (14)0.040 (5)*
C10.11611 (15)0.2777 (3)1.04676 (13)0.0366 (4)
C20.19073 (15)0.4857 (3)1.07814 (14)0.0396 (4)
H2A0.14320.59671.11030.048*
H2B0.21350.55941.01800.048*
C30.30163 (15)0.4327 (3)1.14977 (14)0.0402 (4)
C40.39148 (17)0.6213 (4)1.16260 (17)0.0569 (6)
H4A0.44580.59311.22270.085*
H4B0.35260.76841.16850.085*
H4C0.43420.62451.10500.085*
C50.26749 (16)0.1014 (3)0.95289 (13)0.0395 (4)
C60.38486 (19)0.1467 (4)0.86308 (18)0.0602 (6)
H6A0.39930.31340.86390.072*
H6B0.45030.07260.90520.072*
C70.3797 (2)0.0600 (6)0.75944 (19)0.0775 (8)
H7A0.31130.12360.71890.116*
H7B0.45010.10650.73190.116*
H7C0.37440.10710.75950.116*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0351 (7)0.0546 (8)0.0588 (9)0.0060 (6)0.0140 (6)0.0116 (6)
O30.0575 (9)0.0560 (9)0.0576 (9)0.0001 (7)0.0013 (7)0.0109 (7)
O50.0416 (8)0.0606 (9)0.0615 (9)0.0149 (7)0.0164 (7)0.0108 (7)
O60.0466 (8)0.0519 (8)0.0655 (9)0.0038 (6)0.0224 (7)0.0126 (7)
N10.0333 (8)0.0410 (8)0.0480 (9)0.0083 (7)0.0104 (7)0.0063 (7)
C10.0334 (9)0.0382 (9)0.0379 (9)0.0000 (7)0.0038 (7)0.0029 (7)
C20.0360 (9)0.0355 (9)0.0474 (10)0.0003 (8)0.0059 (8)0.0016 (8)
C30.0385 (10)0.0437 (10)0.0391 (10)0.0011 (8)0.0084 (7)0.0062 (8)
C40.0439 (11)0.0606 (13)0.0657 (14)0.0126 (10)0.0055 (10)0.0130 (11)
C50.0367 (9)0.0445 (10)0.0382 (9)0.0027 (8)0.0079 (7)0.0004 (8)
C60.0472 (12)0.0670 (14)0.0700 (15)0.0080 (11)0.0216 (10)0.0084 (12)
C70.0589 (14)0.117 (2)0.0601 (14)0.0085 (15)0.0206 (11)0.0080 (15)
Geometric parameters (Å, º) top
O1—C11.214 (2)C2—H2B0.9700
O3—C31.203 (2)C3—C41.482 (3)
O5—C51.196 (2)C4—H4A0.9600
O6—C51.327 (2)C4—H4B0.9600
O6—C61.457 (2)C4—H4C0.9600
N1—C11.373 (2)C6—C71.462 (3)
N1—C51.375 (2)C6—H6A0.9700
N1—H10.85 (2)C6—H6B0.9700
C1—C21.492 (2)C7—H7A0.9600
C2—C31.511 (3)C7—H7B0.9600
C2—H2A0.9700C7—H7C0.9600
C5—O6—C6117.11 (16)C3—C4—H4C109.5
C1—N1—C5127.96 (16)H4A—C4—H4C109.5
C1—N1—H1114.4 (13)H4B—C4—H4C109.5
C5—N1—H1117.6 (13)O5—C5—O6125.66 (17)
O1—C1—N1118.55 (16)O5—C5—N1126.43 (18)
O1—C1—C2121.93 (16)O6—C5—N1107.91 (15)
N1—C1—C2119.50 (15)O6—C6—C7111.27 (19)
C1—C2—C3114.48 (15)O6—C6—H6A109.4
C1—C2—H2A108.6C7—C6—H6A109.4
C3—C2—H2A108.6O6—C6—H6B109.4
C1—C2—H2B108.6C7—C6—H6B109.4
C3—C2—H2B108.6H6A—C6—H6B108.0
H2A—C2—H2B107.6C6—C7—H7A109.5
O3—C3—C4123.12 (18)C6—C7—H7B109.5
O3—C3—C2121.22 (17)H7A—C7—H7B109.5
C4—C3—C2115.65 (17)C6—C7—H7C109.5
C3—C4—H4A109.5H7A—C7—H7C109.5
C3—C4—H4B109.5H7B—C7—H7C109.5
H4A—C4—H4B109.5
C5—N1—C1—O1177.59 (17)C6—O6—C5—O50.3 (3)
C5—N1—C1—C23.4 (3)C6—O6—C5—N1179.38 (16)
O1—C1—C2—C3113.35 (19)C1—N1—C5—O55.2 (3)
N1—C1—C2—C367.7 (2)C1—N1—C5—O6174.53 (17)
C1—C2—C3—O315.7 (3)C5—O6—C6—C790.1 (2)
C1—C2—C3—C4165.63 (16)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O1i0.85 (2)2.07 (2)2.923 (2)176 (1)
Symmetry code: (i) x, y, z+2.

Experimental details

Crystal data
Chemical formulaC7H11NO4
Mr173.17
Crystal system, space groupMonoclinic, P21/n
Temperature (K)300
a, b, c (Å)11.366 (2), 5.7345 (13), 13.327 (3)
β (°) 97.388 (5)
V3)861.4 (3)
Z4
Radiation typeMo Kα
µ (mm1)0.11
Crystal size (mm)0.40 × 0.35 × 0.15
Data collection
DiffractometerBruker CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2001)
Tmin, Tmax0.87, 0.98
No. of measured, independent and
observed [I > 2σ(I)] reflections
5292, 2044, 1489
Rint0.022
(sin θ/λ)max1)0.667
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.054, 0.139, 1.04
No. of reflections2044
No. of parameters115
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.21, 0.15

Computer programs: SMART (Bruker, 2001), SAINT-Plus (Bruker, 2001), SAINT-Plus, SHELXTL-NT (Bruker, 2001), SHELXTL-NT.

Selected geometric parameters (Å, º) top
O1—C11.214 (2)N1—C11.373 (2)
O3—C31.203 (2)N1—C51.375 (2)
O5—C51.196 (2)N1—H10.85 (2)
O6—C51.327 (2)C1—C21.492 (2)
O6—C61.457 (2)C2—C31.511 (3)
C5—O6—C6117.11 (16)O3—C3—C4123.12 (18)
C1—N1—C5127.96 (16)O3—C3—C2121.22 (17)
C1—N1—H1114.4 (13)C4—C3—C2115.65 (17)
C5—N1—H1117.6 (13)O5—C5—O6125.66 (17)
O1—C1—N1118.55 (16)O5—C5—N1126.43 (18)
O1—C1—C2121.93 (16)O6—C5—N1107.91 (15)
N1—C1—C2119.50 (15)O6—C6—C7111.27 (19)
C1—C2—C3114.48 (15)
C5—N1—C1—O1177.59 (17)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···O1i0.85 (2)2.07 (2)2.923 (2)176 (1)
Symmetry code: (i) x, y, z+2.
 

Subscribe to Acta Crystallographica Section E: Crystallographic Communications

The full text of this article is available to subscribers to the journal.

If you have already registered and are using a computer listed in your registration details, please email support@iucr.org for assistance.

Buy online

You may purchase this article in PDF and/or HTML formats. For purchasers in the European Community who do not have a VAT number, VAT will be added at the local rate. Payments to the IUCr are handled by WorldPay, who will accept payment by credit card in several currencies. To purchase the article, please complete the form below (fields marked * are required), and then click on `Continue'.
E-mail address* 
Repeat e-mail address* 
(for error checking) 

Format*   PDF (US $40)
   HTML (US $40)
   PDF+HTML (US $50)
In order for VAT to be shown for your country javascript needs to be enabled.

VAT number 
(non-UK EC countries only) 
Country* 
 

Terms and conditions of use
Contact us

Follow Acta Cryst. E
Sign up for e-alerts
Follow Acta Cryst. on Twitter
Follow us on facebook
Sign up for RSS feeds