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access1-Methyl-4H-3,1-benzoxazine-2,4(1H)dione
aDepartment of Chemistry, The George Washington University, 725 21st Street, NW, Washington, DC 20052, USA, and bDepartment of Chemistry, The College of New Jersey, 2000 Pennington Rd, Ewing, NJ 08628, USA
*Correspondence e-mail: chan@tcnj.edu
In its the title compound, C9H7NO3, forms π-stacked dimers, with a centroid–centroid distance of 3.475 (5) Å between the benzenoid and the 2,4 dicarbonyl oxazine rings. These dimers then form staircase-like linear chains through further π-stacking between the benzenoid rings [centroid–centroid distance of 3.761 (2) Å]. The methyl-H atoms are disordered due to rotation about the C—N bond and were modeled with equal occupancy.
Related literature
The title compound is a key intermediate for the synthesis of a variety of compounds, see: Coppola (1980![[Coppola, G. M. (1980). Synthesis, pp. 505-536.]](../../../../../../logos/arrows/e_arr.gif "Coppola, G. M. (1980). Synthesis, pp. 505-536.")
); Kappe & Stadlbauer (1981); Shvekhgeimer (2001). Isatoaic are important for the synthesis of a variety of commercial compounds. The crystal structures of two other isotoic anydrides have been reported: for the brominated 6-bromo-2H-3,1-benzoxazine-2,4(1H)-dione, see: Lubini & Wouters (1996) and for the unfunctionalized 2H-3,1-benzoxazine-2,4(1H)-dione, see: Kashino et al. (1978).
![[Scheme 1]](fj2280scheme1.gif)
Experimental
Crystal data
|
Data collection: APEX2 (Bruker, 2008); cell SAINT-Plus (Bruker, 2008); data reduction: SAINT-Plus (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: CrystalMaker (CrystalMaker, 2009); software used to prepare material for publication: WinGX (Farrugia, 1999).
Supporting information
contains datablocks I, global. DOI: 10.1107/S1600536810006094/fj2280sup1.cif
Structure factors: contains datablock I. DOI: 10.1107/S1600536810006094/fj2280Isup2.hkl
During the course of the reaction of N-substituted isatoic and 2-chloroethylamine hydrochloride, unreacted 1 was isolated from products via silica gel in a 98:2 dichloromethane/methanol mobile phase. The 98:2 was slowly evaporated to produce colorless rods and blocks of 1. A block was chosen for X-ray analysis, the rods gave the same as the block.
The structure was solved using The hydrogen atoms were positioned geometrically. A small improvement in the occurred when the methyl hydrogens were modeled as 50% disordered due to about the C—N bond.
Data collection: APEX2 (Bruker, 2008); cell SAINT-Plus (Bruker, 2008); data reduction: SAINT-PlusS (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: CrystalMaker (CrystalMaker, 2009); software used to prepare material for publication: WinGX (Farrugia, 1999).
![[Figure 1]](./fj2280fig1thm.gif) | Fig. 1. Thermal ellipsoid plot at 50% probability, the disordered hydrogen atoms were removed for clarity. |
![[Figure 2]](./fj2280fig2thm.gif) | Fig. 2. The packing diagram viewed along the b axis shows π-stacked dimers that are separated by 3.475 (5) Å (centroid to centroid shown as a blue dashed line). A staircase-like linear chain forms from additional π-stacking through the bezenoid rings (3.761 (2) Å). Oxygen atoms are shown in red, nitrogen atoms in blue, carbon atoms in red and the hydrogen atoms in white. |
| C9H7NO3 | F(000) = 368 |
| Mr = 177.16 | Dx = 1.495 Mg m−3 |
| Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
| Hall symbol: -P 2yn | Cell parameters from 5577 reflections |
| a = 7.632 (2) Å | θ = 5.8–59.2° |
| b = 8.818 (2) Å | µ = 0.11 mm−1 |
| c = 11.719 (3) Å | T = 296 K |
| β = 93.599 (4)° | Block, colorless |
| V = 787.1 (4) Å3 | 0.5 × 0.5 × 0.4 mm |
| Z = 4 |
| Bruker APEXII CCD diffractometer | 2191 independent reflections |
| Radiation source: fine-focus sealed tube | 1532 reflections with I > 2σ(I) |
| Graphite monochromator | Rint = 0.029 |
| ω and ϕ scans | θmax = 30.1°, θmin = 2.9° |
| Absorption correction: multi-scan (SADABS; Bruker, 2008) | h = −10→10 |
| Tmin = 0.902, Tmax = 0.934 | k = −9→12 |
| 13548 measured reflections | l = −16→16 |
| Refinement on F2 | Primary atom site location: structure-invariant direct methods |
| Least-squares matrix: full | Secondary atom site location: difference Fourier map |
| R[F2 > 2σ(F2)] = 0.052 | Hydrogen site location: inferred from neighbouring sites |
| wR(F2) = 0.160 | H-atom parameters constrained |
| S = 1.07 | w = 1/[σ2(Fo2) + (0.0717P)2 + 0.1822P] where P = (Fo2 + 2Fc2)/3 |
| 2191 reflections | (Δ/σ)max < 0.001 |
| 118 parameters | Δρmax = 0.20 e Å−3 |
| 0 restraints | Δρmin = −0.21 e Å−3 |
| C9H7NO3 | V = 787.1 (4) Å3 |
| Mr = 177.16 | Z = 4 |
| Monoclinic, P21/n | Mo Kα radiation |
| a = 7.632 (2) Å | µ = 0.11 mm−1 |
| b = 8.818 (2) Å | T = 296 K |
| c = 11.719 (3) Å | 0.5 × 0.5 × 0.4 mm |
| β = 93.599 (4)° |
| Bruker APEXII CCD diffractometer | 2191 independent reflections |
| Absorption correction: multi-scan (SADABS; Bruker, 2008) | 1532 reflections with I > 2σ(I) |
| Tmin = 0.902, Tmax = 0.934 | Rint = 0.029 |
| 13548 measured reflections |
| R[F2 > 2σ(F2)] = 0.052 | 0 restraints |
| wR(F2) = 0.160 | H-atom parameters constrained |
| S = 1.07 | Δρmax = 0.20 e Å−3 |
| 2191 reflections | Δρmin = −0.21 e Å−3 |
| 118 parameters |
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 > 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. |
| x | y | z | Uiso*/Ueq | Occ. (<1) | |
| O3 | 0.9373 (2) | 0.59606 (17) | 0.17004 (14) | 0.0830 (5) | |
| O2 | 0.9649 (2) | 1.0762 (2) | 0.27147 (12) | 0.0906 (6) | |
| O1 | 0.93997 (16) | 0.83752 (18) | 0.21847 (10) | 0.0668 (4) | |
| N1 | 0.80524 (17) | 0.76241 (15) | 0.04367 (11) | 0.0494 (3) | |
| C1 | 0.8953 (2) | 0.7229 (2) | 0.14315 (15) | 0.0576 (4) | |
| C2 | 0.9119 (2) | 0.9903 (2) | 0.19846 (14) | 0.0596 (5) | |
| C3 | 0.7855 (2) | 1.1789 (2) | 0.06087 (16) | 0.0607 (5) | |
| H3 | 0.8214 | 1.2561 | 0.1112 | 0.073* | |
| C4 | 0.6984 (3) | 1.2139 (2) | −0.04182 (18) | 0.0662 (5) | |
| H4 | 0.6748 | 1.3144 | −0.0613 | 0.079* | |
| C5 | 0.6463 (2) | 1.0989 (2) | −0.11575 (15) | 0.0591 (4) | |
| H5 | 0.5872 | 1.1228 | −0.1853 | 0.071* | |
| C6 | 0.6794 (2) | 0.95018 (19) | −0.08922 (13) | 0.0488 (4) | |
| H6 | 0.6430 | 0.8742 | −0.1404 | 0.059* | |
| C7 | 0.76789 (17) | 0.91246 (16) | 0.01464 (11) | 0.0402 (3) | |
| C8 | 0.82028 (18) | 1.02777 (18) | 0.08998 (12) | 0.0462 (4) | |
| C9 | 0.7552 (3) | 0.6393 (2) | −0.0348 (2) | 0.0780 (6) | |
| H9A | 0.6927 | 0.6799 | −0.1016 | 0.117* | 0.50 |
| H9B | 0.6811 | 0.5691 | 0.0022 | 0.117* | 0.50 |
| H9C | 0.8587 | 0.5878 | −0.0567 | 0.117* | 0.50 |
| H9D | 0.7956 | 0.5446 | −0.0025 | 0.117* | 0.50 |
| H9E | 0.8072 | 0.6554 | −0.1063 | 0.117* | 0.50 |
| H9F | 0.6297 | 0.6367 | −0.0474 | 0.117* | 0.50 |
| U11 | U22 | U33 | U12 | U13 | U23 | |
| O3 | 0.0874 (10) | 0.0758 (10) | 0.0840 (10) | 0.0213 (8) | −0.0077 (8) | 0.0243 (8) |
| O2 | 0.0825 (10) | 0.1184 (14) | 0.0673 (9) | −0.0039 (9) | −0.0231 (7) | −0.0386 (9) |
| O1 | 0.0639 (7) | 0.0889 (10) | 0.0455 (6) | 0.0043 (7) | −0.0147 (5) | 0.0028 (6) |
| N1 | 0.0527 (7) | 0.0442 (7) | 0.0499 (7) | 0.0013 (5) | −0.0079 (5) | −0.0009 (5) |
| C1 | 0.0515 (9) | 0.0646 (11) | 0.0558 (9) | 0.0072 (7) | −0.0025 (7) | 0.0104 (8) |
| C2 | 0.0470 (8) | 0.0819 (13) | 0.0489 (8) | −0.0014 (8) | −0.0060 (6) | −0.0148 (8) |
| C3 | 0.0554 (9) | 0.0509 (10) | 0.0758 (11) | −0.0090 (7) | 0.0049 (8) | −0.0169 (8) |
| C4 | 0.0670 (11) | 0.0474 (10) | 0.0839 (13) | −0.0007 (8) | 0.0030 (9) | 0.0084 (8) |
| C5 | 0.0597 (10) | 0.0622 (11) | 0.0549 (9) | 0.0018 (8) | −0.0015 (7) | 0.0128 (8) |
| C6 | 0.0505 (8) | 0.0531 (9) | 0.0418 (7) | −0.0028 (7) | −0.0048 (6) | −0.0009 (6) |
| C7 | 0.0368 (6) | 0.0443 (8) | 0.0393 (6) | −0.0016 (5) | 0.0001 (5) | −0.0022 (5) |
| C8 | 0.0390 (7) | 0.0530 (9) | 0.0463 (7) | −0.0044 (6) | 0.0003 (5) | −0.0095 (6) |
| C9 | 0.0984 (15) | 0.0469 (10) | 0.0854 (14) | 0.0068 (10) | −0.0219 (11) | −0.0154 (9) |
| O3—C1 | 1.201 (2) | C4—H4 | 0.9300 |
| O2—C2 | 1.194 (2) | C5—C6 | 1.368 (2) |
| O1—C1 | 1.371 (2) | C5—H5 | 0.9300 |
| O1—C2 | 1.382 (3) | C6—C7 | 1.3944 (19) |
| N1—C1 | 1.361 (2) | C6—H6 | 0.9300 |
| N1—C7 | 1.3912 (19) | C7—C8 | 1.3888 (19) |
| N1—C9 | 1.459 (2) | C9—H9A | 0.9600 |
| C2—C8 | 1.450 (2) | C9—H9B | 0.9600 |
| C3—C4 | 1.373 (3) | C9—H9C | 0.9600 |
| C3—C8 | 1.397 (3) | C9—H9D | 0.9600 |
| C3—H3 | 0.9300 | C9—H9E | 0.9600 |
| C4—C5 | 1.376 (3) | C9—H9F | 0.9600 |
| C1—O1—C2 | 125.43 (13) | C7—C8—C3 | 120.04 (14) |
| C1—N1—C7 | 122.51 (14) | C7—C8—C2 | 119.62 (15) |
| C1—N1—C9 | 116.62 (15) | C3—C8—C2 | 120.34 (15) |
| C7—N1—C9 | 120.81 (13) | N1—C9—H9A | 109.5 |
| O3—C1—N1 | 125.14 (18) | N1—C9—H9B | 109.5 |
| O3—C1—O1 | 117.80 (16) | H9A—C9—H9B | 109.5 |
| N1—C1—O1 | 117.06 (15) | N1—C9—H9C | 109.5 |
| O2—C2—O1 | 117.05 (18) | H9A—C9—H9C | 109.5 |
| O2—C2—C8 | 127.4 (2) | H9B—C9—H9C | 109.5 |
| O1—C2—C8 | 115.59 (14) | N1—C9—H9D | 109.5 |
| C4—C3—C8 | 120.15 (16) | H9A—C9—H9D | 141.1 |
| C4—C3—H3 | 119.9 | H9B—C9—H9D | 56.3 |
| C8—C3—H3 | 119.9 | H9C—C9—H9D | 56.3 |
| C3—C4—C5 | 119.44 (17) | N1—C9—H9E | 109.5 |
| C3—C4—H4 | 120.3 | H9A—C9—H9E | 56.3 |
| C5—C4—H4 | 120.3 | H9B—C9—H9E | 141.1 |
| C6—C5—C4 | 121.41 (16) | H9C—C9—H9E | 56.3 |
| C6—C5—H5 | 119.3 | H9D—C9—H9E | 109.5 |
| C4—C5—H5 | 119.3 | N1—C9—H9F | 109.5 |
| C5—C6—C7 | 119.98 (15) | H9A—C9—H9F | 56.3 |
| C5—C6—H6 | 120.0 | H9B—C9—H9F | 56.3 |
| C7—C6—H6 | 120.0 | H9C—C9—H9F | 141.1 |
| C8—C7—N1 | 119.63 (13) | H9D—C9—H9F | 109.5 |
| C8—C7—C6 | 118.98 (14) | H9E—C9—H9F | 109.5 |
| N1—C7—C6 | 121.39 (13) |
Experimental details
| Crystal data | |
| Chemical formula | C9H7NO3 |
| Mr | 177.16 |
| Crystal system, space group | Monoclinic, P21/n |
| Temperature (K) | 296 |
| a, b, c (Å) | 7.632 (2), 8.818 (2), 11.719 (3) |
| β (°) | 93.599 (4) |
| V (Å3) | 787.1 (4) |
| Z | 4 |
| Radiation type | Mo Kα |
| µ (mm−1) | 0.11 |
| Crystal size (mm) | 0.5 × 0.5 × 0.4 |
| Data collection | |
| Diffractometer | Bruker APEXII CCD diffractometer |
| Absorption correction | Multi-scan (SADABS; Bruker, 2008) |
| Tmin, Tmax | 0.902, 0.934 |
| No. of measured, independent and observed [I > 2σ(I)] reflections | 13548, 2191, 1532 |
| Rint | 0.029 |
| (sin θ/λ)max (Å−1) | 0.706 |
| Refinement | |
| R[F2 > 2σ(F2)], wR(F2), S | 0.052, 0.160, 1.07 |
| No. of reflections | 2191 |
| No. of parameters | 118 |
| H-atom treatment | H-atom parameters constrained |
| Δρmax, Δρmin (e Å−3) | 0.20, −0.21 |
Computer programs: APEX2 (Bruker, 2008), SAINT-Plus (Bruker, 2008), SAINT-PlusS (Bruker, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), CrystalMaker (CrystalMaker, 2009), WinGX (Farrugia, 1999).
Acknowledgements
The authors thank Christopher Cahill for the use of his APEXII diffractometer and the Petroleum Research Fund (grant No. 48381-GB10) for travel funds.
References
Bruker (2008). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Coppola, G. M. (1980). Synthesis, pp. 505–536. CrossRef Google Scholar
CrystalMaker (2009). CrystalMaker. CrystalMaker Software, Bicester, England (www.CrystalMaker.com). Google Scholar
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. CrossRef CAS IUCr Journals Google Scholar
Kappe, T. & Stadlbauer, W. (1981). Advances in Heterocyclic Chemistry, Vol. 28, Isatoic Anhydrides and their Use in Heterocyclic Chemistry, pp. 231–361. London: Academic Press. Google Scholar
Kashino, S., Nakashima, S. & Haisa, M. (1978). Acta Cryst. B34, 2191–2195. CSD CrossRef CAS IUCr Journals Web of Science Google Scholar
Lubini, P. & Wouters, J. (1996). Acta Cryst. C52, 3108–3110. CSD CrossRef CAS Web of Science IUCr Journals Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Shvekhgeimer, M.-G. A. (2001). Chem. Heterocycl. Compd, 37, 285–443. Google Scholar
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| CRYSTALLOGRAPHIC COMMUNICATIONS |
1-Methyl-2H-3,1- benzoxazine-2,4(1H)-dione (N-methylisatoic anhydride, 1) is a key intermediate for the synthesis of a variety of compounds, such as agricultural chemicals, dyes/pigments flavors, fragrances, pharmaceuticals, ultraviolet absorbers, as well as esters, thioesters and amides of N-methylanthranilic acid (Kappe and Stadlbauer, 1981; Coppola, 1980; Shvekhgeimer, 2001). During the investigation of a novel o-aminoaryl oxazoline synthesis from the reaction of N-substituted isatoic anhydrides and 2-chloroethylamine hydrochloride in DMSO using an equimolar quantity of base, o-amino thiomethyl esters were observed as side products. In some cases, an o-amino thiomethyl ester was the major product (Hunt and Cherney, unpublished results).
The title compound is a planar molecule (Fig. 1). The bond distances are consistent with an aromatic system. The packing diagram, (Fig. 2) shows the aromatic rings form pi stacked dimers between the benzenoid ring and the 2,4 dicarbonyl oxazine ring, 3.475 (5) Å for both centroid to centroid distances (Crystalmaker ver. 2.1.2). The dimer forms a staircase-like linear chain through additional pi stacking between the benzenoid rings (3.761 (2) Å centroid to centroid).