research communications
H-benzo[c][1,2]thiazine-3-carboxylate 2,2-dioxide
of methyl 1-allyl-4-methyl-1aNational Polytechnic Institute, CIITEC, Cerrada Cecati S/N, Colonia Santa Catarina de Azcapotzalco, CP 02250, Mexico, DF, Mexico, bSSI `Institute for Single Crystals', National Academy of Sciences of Ukraine, 60 Lenina Avenue, Kharkiv 61001, Ukraine, cNational University of Pharmacy, 4 Blyukhera St., Kharkiv 61168, Ukraine, and dMexican Institute of Petroleum, Eje Central Lazaro Cardenas Norte 152, Col. San Bartolo Atepehuacan, 07730 Mexico, DF, Mexico
*Correspondence e-mail: sveta@xray.isc.kharkov.com
In the title compound, C14H15NO4S, the dihydrothiazine ring adopts a distorted sofa conformation with the S atom displaced from the mean plane through the N and C ring atoms by 0.767 (1) Å. The allyl substituent (C—C=C) is inclined to this mean plane by 78.5 (7)° and the acetate group [C(=O)—O—C] by 66.5 (3)°. In the crystal, molecules are linked by C—H⋯π interactions forming chains propagating along the a-axis direction.
Keywords: crystal structure; benzothiazine; allyl; C—H⋯π interactions.
CCDC reference: 1508990
1. Chemical context
Alkylation of nitrogen heterocycles, particularly those containing reactive exocyclic groups, always attracts attention with its ambiguity and dependence on a variety of factors. For example, et al., 1996). However, methyl 4-hydroxy-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylates that are structurally close to them easily form mixtures of isomeric 3-C- and 4-O-alkylation products under the same conditions (Ukrainets et al., 2015). Consequently, it is quite difficult to predict their behaviour in the alkylation reactions of the of 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylic acids, and the determination of the true structure is essential. It has been found that methyl 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylate 1 in the K2CO3/DMSO system is rapidly alkylated with allyl bromide 2 by the cyclic nitrogen atom, with formation of the main product of the reaction studied viz. compound 3 (see Fig. 1).
of 4-hydroxy-2-oxo-1,2-dihydroquinoline-3-carboxylic acids are primarily alkylated exclusively at the 4-OH group (Ukrainets2. Structural commentary
The molecular structure of the title compound, 3, is illustrated in Fig. 2. The dihydrothiazine ring adopts a distorted sofa conformation: the puckering parameters (Zefirov et al., 1990) are: S = 0.67, Θ = 57.1°, Ψ = 19.0°. Atom S1 deviates from the mean plane of the remaining atoms (N1/C1/C6–C8) by 0.767 (1) Å. The allyl substituent (C—C=C) is inclined to this mean plane by 78.5 (7)° and the acetate group (O=C—O—C) by 66.5 (3)°. Atom N1 has a planar configuration, the sum of the bond angles being 359.1°.
The strong steric repulsion between methyl group at the C7 atom and the aromatic ring {there are short intramolecular contacts H5⋯C11 = 2.63 and H11A⋯C5 = 2.47 Å in this fragment [the sum of the van der Waals radii (Zefirov, 1997) is 2.87 Å]} causes a disturbance of the conjugation between the π-systems of the aromatic ring and the C7=C8 double bond; the C5—C6—C7—C8 torsion angle is −164.7 (4)°. The ester substituent is twisted relatively to the C7=C8 endocyclic double bond [the C7—C8—C9—O1 torsion angle is 46.0 (7)°], leading to its elongation: the C7=C8 bond length is 1.348 (6) Å as compared to the mean value of 1.326 Å (Bürgi & Dunitz, 1994). The methyl group of the ester substituent is located in the ap-position to the C8—C9 bond [C8—C9—O2—C10 = −171.5 (5)°]. The allyl group is orthogonal to the benzothiazine fragment plane while the terminal double bond is to the N1—C12 bond [torsion angles C1—N1—C12—C13 and N1—C12—C13—C14 are 97.2 (5) and 3.5 (8)°, respectively]. The steric repulsion between the allyl substituent and the aromatic cycle (short intramolecular contacts H2⋯C12 = 2.77 Å and H12A⋯C2 = 2.83 Å) results in the elongation of the C1—N1 bond [1.411 (5) Å], compared with the mean value of 1.371 Å (Bürgi & Dunitz, 1994).
3. Supramolecular features
In the crystal, molecules are linked by C—H⋯π interactions, forming chains propagating along the a-axis direction. (Table 1 and Fig. 3). There are no other significant intermolecular interactions in the despite the presence of a number of potential donor and acceptor atoms.
4. Database survey
A search of the Cambridge Structural Database (Version 5.37, update May 2016; Groom et al., 2016) for 1H-benzo[c][1,2]thiazine 2,2-dioxide yielded 15 hits. These include the 4-hydroxy analogue of the title compound, viz. methyl 1-allyl-4-hydroxy-1H-benzo[c][1,2]thiazine-3-carboxylate 2,2-dioxide (MINJAW; Shishkina et al., 2013). This compound crystallized with two molecules in the The conformation of the dihydrothiazine ring in both molecules resembles that in the title compound, which has a distorted sofa conformation. A view of the structural overlap of the three molecules is shown in Fig. 4.
5. Synthesis and crystallization
The synthesis of the title compound, 3, is illustrated in Fig. 1. To a solution of 2.53 g (0.01 mol) of methyl 4-methyl-2,2-dioxo-1H-2λ6,1-benzothiazine-3-carboxylate, 1, in 20 ml DMSO were added 2.07 g (0.015 mol) of K2CO3 and the mixture was stirred for 30 min. Allyl bromide (1.81 g, 0.015 mol) was then added and the mixture was stirred for a further 30 min at 298 K. It was then diluted with cold water and acidified with dilute HCl to pH 4. It was extracted with CH2Cl2 (3 × 10 ml). The organic extracts were combined and the solvent removed by distillation (at reduced pressure at the end). The residue was dissolved in 20 ml of hot methanol and filtered over The resulting solution was then placed in a freezer (253 K) for 24 h, after which crystals of the title compound were harvested (yield 2.55 g, 87%; m.p. 360–362 K).
6. Refinement
Crystal data, data collection and structure . H atoms could all be located in difference Fourier maps. During they were included in calculated positions and treated as riding: C—H = 0.93–0.97 Å with Uiso = 1.5Ueq(C-methyl) and 1.2Ueq(C) for other H atoms.
details are summarized in Table 2Supporting information
CCDC reference: 1508990
https://doi.org/10.1107/S2056989016015978/su5329sup1.cif
contains datablocks I, Global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989016015978/su5329Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S2056989016015978/su5329Isup3.cml
Data collection: CrysAlis CCD (Agilent, 2012); cell
CrysAlis CCD (Agilent, 2012); data reduction: CrysAlis RED (Agilent, 2012); program(s) used to solve structure: SHELXS2014 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015); molecular graphics: SHELXTL (Sheldrick, 2008) and Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL2014 (Sheldrick, 2015), PLATON (Spek, 2009) and publCIF (Westrip, 2010).C14H15NO4S | Dx = 1.366 Mg m−3 |
Mr = 293.33 | Mo Kα radiation, λ = 0.71073 Å |
Orthorhombic, Pna21 | Cell parameters from 2163 reflections |
a = 10.1970 (7) Å | θ = 3.8–25.1° |
b = 18.6174 (12) Å | µ = 0.24 mm−1 |
c = 7.5136 (5) Å | T = 293 K |
V = 1426.39 (16) Å3 | Plate, colourless |
Z = 4 | 0.20 × 0.10 × 0.02 mm |
F(000) = 616 |
Agilent Xcalibur Sapphire3 diffractometer | 2425 independent reflections |
Radiation source: Enhance (Mo) X-ray Source | 2111 reflections with I > 2σ(I) |
Detector resolution: 16.1827 pixels mm-1 | Rint = 0.056 |
ω–scans | θmax = 25.0°, θmin = 3.0° |
Absorption correction: multi-scan (CrysAlis RED; Agilent, 2012) | h = −12→10 |
Tmin = 0.706, Tmax = 1.000 | k = −22→22 |
9346 measured reflections | l = −7→8 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.044 | H-atom parameters constrained |
wR(F2) = 0.120 | w = 1/[σ2(Fo2) + (0.0618P)2 + 0.1291P] where P = (Fo2 + 2Fc2)/3 |
S = 1.05 | (Δ/σ)max < 0.001 |
2425 reflections | Δρmax = 0.19 e Å−3 |
181 parameters | Δρmin = −0.20 e Å−3 |
1 restraint | Absolute structure: Flack x determined using 785 quotients [(I+)-(I-)]/[(I+)+(I-)] (Parsons et al., 2013) |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.09 (8) |
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. |
x | y | z | Uiso*/Ueq | ||
S1 | 0.88243 (9) | 0.65549 (5) | 0.26457 (17) | 0.0457 (3) | |
O1 | 0.6502 (4) | 0.5240 (2) | 0.4865 (7) | 0.0975 (14) | |
O2 | 0.7649 (4) | 0.51032 (18) | 0.2347 (6) | 0.0801 (11) | |
O3 | 0.7789 (3) | 0.66144 (16) | 0.1376 (5) | 0.0645 (9) | |
O4 | 1.0109 (3) | 0.63899 (17) | 0.2033 (4) | 0.0590 (9) | |
N1 | 0.8881 (3) | 0.73110 (17) | 0.3775 (5) | 0.0457 (8) | |
C1 | 0.9692 (4) | 0.7307 (2) | 0.5295 (6) | 0.0443 (9) | |
C2 | 1.0333 (4) | 0.7933 (3) | 0.5818 (7) | 0.0559 (11) | |
H2 | 1.0205 | 0.8355 | 0.5180 | 0.067* | |
C3 | 1.1146 (4) | 0.7932 (3) | 0.7260 (7) | 0.0652 (14) | |
H3 | 1.1557 | 0.8355 | 0.7611 | 0.078* | |
C4 | 1.1362 (5) | 0.7308 (3) | 0.8195 (7) | 0.0722 (15) | |
H4 | 1.1956 | 0.7305 | 0.9135 | 0.087* | |
C5 | 1.0705 (5) | 0.6690 (3) | 0.7747 (8) | 0.0605 (11) | |
H5 | 1.0837 | 0.6277 | 0.8419 | 0.073* | |
C6 | 0.9842 (4) | 0.6670 (2) | 0.6302 (6) | 0.0461 (10) | |
C7 | 0.9017 (4) | 0.6034 (2) | 0.5943 (6) | 0.0490 (10) | |
C8 | 0.8424 (4) | 0.5951 (2) | 0.4353 (6) | 0.0497 (11) | |
C9 | 0.7425 (5) | 0.5388 (2) | 0.3921 (8) | 0.0623 (13) | |
C10 | 0.6651 (7) | 0.4617 (4) | 0.1624 (12) | 0.110 (3) | |
H10A | 0.6927 | 0.4446 | 0.0478 | 0.165* | |
H10B | 0.6537 | 0.4217 | 0.2415 | 0.165* | |
H10C | 0.5835 | 0.4870 | 0.1506 | 0.165* | |
C11 | 0.8826 (5) | 0.5494 (3) | 0.7415 (9) | 0.0715 (15) | |
H11A | 0.9319 | 0.5640 | 0.8442 | 0.107* | |
H11B | 0.7913 | 0.5467 | 0.7717 | 0.107* | |
H11C | 0.9126 | 0.5031 | 0.7025 | 0.107* | |
C12 | 0.7970 (4) | 0.7897 (2) | 0.3411 (7) | 0.0547 (11) | |
H12A | 0.7753 | 0.8127 | 0.4530 | 0.066* | |
H12B | 0.7168 | 0.7693 | 0.2936 | 0.066* | |
C13 | 0.8440 (5) | 0.8458 (2) | 0.2154 (8) | 0.0661 (15) | |
H13 | 0.7888 | 0.8848 | 0.1961 | 0.079* | |
C14 | 0.9528 (6) | 0.8455 (3) | 0.1316 (9) | 0.0829 (18) | |
H14A | 1.0112 | 0.8076 | 0.1466 | 0.099* | |
H14B | 0.9737 | 0.8832 | 0.0555 | 0.099* |
U11 | U22 | U33 | U12 | U13 | U23 | |
S1 | 0.0486 (5) | 0.0440 (5) | 0.0446 (5) | −0.0024 (4) | −0.0040 (5) | −0.0029 (5) |
O1 | 0.087 (3) | 0.089 (3) | 0.116 (4) | −0.038 (2) | 0.020 (3) | −0.007 (3) |
O2 | 0.084 (2) | 0.063 (2) | 0.094 (3) | −0.0162 (18) | −0.005 (2) | −0.028 (2) |
O3 | 0.070 (2) | 0.062 (2) | 0.062 (2) | −0.0037 (16) | −0.0255 (17) | −0.0033 (16) |
O4 | 0.0587 (18) | 0.0636 (19) | 0.0546 (19) | −0.0032 (15) | 0.0108 (14) | −0.0081 (14) |
N1 | 0.0528 (19) | 0.0364 (17) | 0.048 (2) | −0.0005 (14) | −0.0052 (15) | −0.0030 (17) |
C1 | 0.044 (2) | 0.046 (2) | 0.043 (2) | −0.0011 (18) | 0.0033 (18) | −0.0031 (18) |
C2 | 0.061 (3) | 0.053 (3) | 0.053 (3) | −0.008 (2) | 0.004 (2) | −0.005 (2) |
C3 | 0.070 (3) | 0.075 (3) | 0.051 (3) | −0.020 (3) | 0.005 (2) | −0.015 (2) |
C4 | 0.075 (3) | 0.096 (4) | 0.046 (3) | −0.009 (3) | −0.013 (2) | −0.008 (3) |
C5 | 0.070 (3) | 0.067 (3) | 0.045 (2) | 0.005 (2) | −0.009 (3) | 0.001 (3) |
C6 | 0.049 (2) | 0.047 (2) | 0.042 (2) | 0.0024 (18) | 0.0034 (18) | −0.0002 (18) |
C7 | 0.055 (2) | 0.042 (2) | 0.050 (3) | 0.0070 (18) | 0.003 (2) | 0.0025 (19) |
C8 | 0.051 (2) | 0.038 (2) | 0.060 (3) | −0.0031 (18) | 0.003 (2) | −0.0031 (19) |
C9 | 0.062 (3) | 0.046 (2) | 0.079 (4) | −0.009 (2) | 0.000 (3) | 0.000 (2) |
C10 | 0.112 (5) | 0.070 (4) | 0.149 (7) | −0.028 (4) | −0.040 (5) | −0.028 (4) |
C11 | 0.093 (4) | 0.053 (3) | 0.068 (4) | −0.001 (2) | −0.002 (3) | 0.014 (3) |
C12 | 0.054 (2) | 0.046 (2) | 0.064 (3) | 0.0025 (19) | −0.001 (2) | 0.001 (2) |
C13 | 0.067 (3) | 0.051 (3) | 0.081 (4) | 0.003 (2) | 0.000 (3) | 0.011 (2) |
C14 | 0.076 (4) | 0.090 (4) | 0.082 (4) | −0.001 (3) | −0.001 (3) | 0.026 (3) |
S1—O4 | 1.422 (3) | C5—H5 | 0.9300 |
S1—O3 | 1.427 (3) | C6—C7 | 1.477 (6) |
S1—N1 | 1.645 (3) | C7—C8 | 1.348 (6) |
S1—C8 | 1.754 (4) | C7—C11 | 1.508 (7) |
O1—C9 | 1.210 (6) | C8—C9 | 1.497 (6) |
O2—C9 | 1.316 (6) | C10—H10A | 0.9600 |
O2—C10 | 1.466 (6) | C10—H10B | 0.9600 |
N1—C1 | 1.411 (5) | C10—H10C | 0.9600 |
N1—C12 | 1.458 (5) | C11—H11A | 0.9600 |
C1—C2 | 1.392 (6) | C11—H11B | 0.9600 |
C1—C6 | 1.415 (6) | C11—H11C | 0.9600 |
C2—C3 | 1.364 (7) | C12—C13 | 1.487 (7) |
C2—H2 | 0.9300 | C12—H12A | 0.9700 |
C3—C4 | 1.376 (8) | C12—H12B | 0.9700 |
C3—H3 | 0.9300 | C13—C14 | 1.276 (8) |
C4—C5 | 1.373 (7) | C13—H13 | 0.9300 |
C4—H4 | 0.9300 | C14—H14A | 0.9300 |
C5—C6 | 1.398 (6) | C14—H14B | 0.9300 |
O4—S1—O3 | 118.8 (2) | C7—C8—C9 | 125.3 (4) |
O4—S1—N1 | 108.66 (18) | C7—C8—S1 | 118.0 (3) |
O3—S1—N1 | 107.72 (19) | C9—C8—S1 | 116.6 (4) |
O4—S1—C8 | 108.2 (2) | O1—C9—O2 | 124.8 (5) |
O3—S1—C8 | 111.5 (2) | O1—C9—C8 | 124.1 (5) |
N1—S1—C8 | 100.3 (2) | O2—C9—C8 | 111.0 (4) |
C9—O2—C10 | 117.4 (5) | O2—C10—H10A | 109.5 |
C1—N1—C12 | 122.0 (3) | O2—C10—H10B | 109.5 |
C1—N1—S1 | 115.7 (3) | H10A—C10—H10B | 109.5 |
C12—N1—S1 | 121.4 (3) | O2—C10—H10C | 109.5 |
C2—C1—N1 | 120.0 (4) | H10A—C10—H10C | 109.5 |
C2—C1—C6 | 120.0 (4) | H10B—C10—H10C | 109.5 |
N1—C1—C6 | 120.0 (3) | C7—C11—H11A | 109.5 |
C3—C2—C1 | 120.5 (5) | C7—C11—H11B | 109.5 |
C3—C2—H2 | 119.7 | H11A—C11—H11B | 109.5 |
C1—C2—H2 | 119.7 | C7—C11—H11C | 109.5 |
C2—C3—C4 | 120.3 (5) | H11A—C11—H11C | 109.5 |
C2—C3—H3 | 119.9 | H11B—C11—H11C | 109.5 |
C4—C3—H3 | 119.9 | N1—C12—C13 | 116.1 (4) |
C5—C4—C3 | 120.3 (5) | N1—C12—H12A | 108.3 |
C5—C4—H4 | 119.9 | C13—C12—H12A | 108.3 |
C3—C4—H4 | 119.9 | N1—C12—H12B | 108.3 |
C4—C5—C6 | 121.4 (5) | C13—C12—H12B | 108.3 |
C4—C5—H5 | 119.3 | H12A—C12—H12B | 107.4 |
C6—C5—H5 | 119.3 | C14—C13—C12 | 126.2 (5) |
C5—C6—C1 | 117.4 (4) | C14—C13—H13 | 116.9 |
C5—C6—C7 | 121.5 (4) | C12—C13—H13 | 116.9 |
C1—C6—C7 | 120.8 (4) | C13—C14—H14A | 120.0 |
C8—C7—C6 | 120.7 (4) | C13—C14—H14B | 120.0 |
C8—C7—C11 | 121.0 (4) | H14A—C14—H14B | 120.0 |
C6—C7—C11 | 118.3 (4) | ||
O4—S1—N1—C1 | −60.7 (3) | C1—C6—C7—C8 | 21.7 (6) |
O3—S1—N1—C1 | 169.5 (3) | C5—C6—C7—C11 | 17.0 (6) |
C8—S1—N1—C1 | 52.7 (3) | C1—C6—C7—C11 | −156.7 (4) |
O4—S1—N1—C12 | 130.1 (3) | C6—C7—C8—C9 | −171.1 (4) |
O3—S1—N1—C12 | 0.2 (4) | C11—C7—C8—C9 | 7.3 (7) |
C8—S1—N1—C12 | −116.5 (3) | C6—C7—C8—S1 | 7.8 (6) |
C12—N1—C1—C2 | −42.8 (5) | C11—C7—C8—S1 | −173.9 (4) |
S1—N1—C1—C2 | 147.9 (3) | O4—S1—C8—C7 | 72.8 (4) |
C12—N1—C1—C6 | 136.3 (4) | O3—S1—C8—C7 | −154.8 (3) |
S1—N1—C1—C6 | −32.9 (5) | N1—S1—C8—C7 | −40.9 (4) |
N1—C1—C2—C3 | −178.4 (4) | O4—S1—C8—C9 | −108.2 (4) |
C6—C1—C2—C3 | 2.5 (6) | O3—S1—C8—C9 | 24.2 (4) |
C1—C2—C3—C4 | 1.2 (7) | N1—S1—C8—C9 | 138.1 (3) |
C2—C3—C4—C5 | −3.6 (8) | C10—O2—C9—O1 | 5.4 (8) |
C3—C4—C5—C6 | 2.4 (8) | C10—O2—C9—C8 | −171.5 (5) |
C4—C5—C6—C1 | 1.2 (7) | C7—C8—C9—O1 | 46.0 (7) |
C4—C5—C6—C7 | −172.6 (5) | S1—C8—C9—O1 | −132.9 (5) |
C2—C1—C6—C5 | −3.6 (6) | C7—C8—C9—O2 | −137.1 (5) |
N1—C1—C6—C5 | 177.2 (4) | S1—C8—C9—O2 | 44.0 (5) |
C2—C1—C6—C7 | 170.3 (4) | C1—N1—C12—C13 | 97.2 (5) |
N1—C1—C6—C7 | −8.9 (6) | S1—N1—C12—C13 | −94.2 (4) |
C5—C6—C7—C8 | −164.7 (4) | N1—C12—C13—C14 | 3.5 (8) |
Cg is the centroid of the C1–C6 ring. |
D—H···A | D—H | H···A | D···A | D—H···A |
C12—H12A···Cgi | 0.97 | 2.95 | 3.576 (5) | 123 |
Symmetry code: (i) −x−1/2, y+3/2, z+1/2. |
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