Methyl (2-benzylidene-3-oxo-1,4-benzothiazin-4-yl)acetate

The structure of the title compound, C₁₈H₁₅NO₃S, established by an X-ray crystallographic study, shows that the six-membered heterocycle of the benzothiazine fragment exhibits a twisted-boat conformation.

Key indicators

• Single-crystal X-ray study
• T = 298 K
• Mean [sigma](C-C) = 0.001 Å
• R factor = 0.039
• wR factor = 0.050
• Data-to-parameter ratio = 13.1

checkCIF results

No syntax errors found

ADDSYM reports no extra symmetry


 Alert Level C:



CRYSC_01  Alert C The word below has not been recognised as a standard
          identifier.
          incolore

CRYSC_01  Alert C No recognised colour has been given for crystal colour.


 0 Alert Level A = Potentially serious problem

 0 Alert Level B = Potential problem

 2 Alert Level C = Please check

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Computing details

Data collection: KappaCCD Reference Manual (Nonius, 1998); data reduction: DENZO and SCALEPACK (Otwinowski & Minor, 1997); program(s) used to solve structure: SIR92 (Altomare et al., 1994); program(s) used to refine structure: maXus (Mackay et al., 1999); molecular graphics: ORTEPII (Johnson, 1976); software used to prepare material for publication: maXus.

Methyl (2-benzylidene-3-oxo-1,4-benzothiazin-4-yl)acetate

Crystal data

C18H15NO3S	F(000) = 680
Mr = 325.39	Dx = 1.352 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 19.0388 (6) Å	Cell parameters from 11 106 reflections
b = 9.6511 (3) Å	θ = 1–26.3°
c = 20.9817 (6) Å	µ = 0.22 mm^−1
β = 155.492 (1)°	T = 298 K
V = 1599.0 (1) Å^3	Cube, incolore
Z = 4	0.40 × 0.40 × 0.35 mm

Data collection

CCD diffractometer	Rint = 0.029
Radiation source: fine-focus sealed tube	θmax = 26.4°
φ scan	h = −23→23
3354 measured reflections	k = −12→0
3127 independent reflections	l = −26→23
2718 reflections with I > 3σ(I)

Refinement

Refinement on F^2	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F^2 > 2σ(F^2)] = 0.039	H-atom parameters constrained
wR(F^2) = 0.050	Weighting scheme based on measured s.u.'s w = 1 /[σ^2(Fo^2) + 0.03Fo^2]
S = 1.40	(Δ/σ)max = 0.005
2718 reflections	Δρmax = 0.19 e Å^−3
208 parameters	Δρmin = −0.18 e Å^−3
Primary atom site location: structure-invariant direct methods

Special details

Geometry. All standard uncertainties (except dihedral angles between l.s. planes) are estimated using the full covariance matrix. The standard uncertainties in cell dimensions are are used in calculating the standard uncertainties of bond distances, angles and torsion angles. Angles between l.s. planes have standard uncertainties calculated from atomic positional standard uncertainties; the errors in cell dimensions are not used in this case.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Ų)

	x	y	z	Uiso*/Ueq
S1	1.053433 (12)	0.342800 (10)	0.137130 (12)	0.12506 (6)
O18	0.63088 (3)	0.54703 (3)	−0.21456 (3)	0.10888 (15)
O21	0.29350 (3)	0.41091 (3)	−0.35915 (3)	0.11597 (15)
O23	0.55140 (4)	0.50038 (3)	−0.13008 (3)	0.13792 (18)
N4	0.68747 (3)	0.34661 (3)	−0.11656 (3)	0.08213 (15)
C2	0.92020 (4)	0.48783 (4)	0.03149 (4)	0.09026 (19)
C3	0.73651 (4)	0.46372 (4)	−0.10846 (4)	0.09314 (19)
C5	0.79921 (4)	0.25548 (3)	0.00846 (4)	0.08782 (18)
C6	0.96912 (5)	0.24534 (4)	0.13048 (4)	0.10138 (19)
C7	1.07599 (5)	0.15340 (4)	0.25000 (5)	0.1200 (2)
C8	1.01641 (6)	0.06880 (4)	0.24839 (5)	0.1474 (3)
C9	0.84985 (5)	0.07912 (4)	0.12931 (5)	0.1505 (3)
C10	0.74245 (5)	0.17301 (4)	0.01160 (4)	0.1104 (2)
C11	0.97168 (4)	0.61876 (4)	0.06645 (4)	0.1014 (2)
C12	1.14406 (4)	0.67295 (4)	0.20209 (4)	0.1031 (2)
C13	1.18065 (5)	0.79825 (4)	0.26207 (5)	0.1412 (2)
C14	1.34378 (6)	0.85035 (5)	0.39766 (5)	0.1662 (3)
C15	1.47099 (6)	0.77946 (5)	0.47211 (6)	0.1431 (3)
C16	1.43584 (5)	0.65891 (5)	0.41105 (5)	0.1442 (3)
C17	1.27340 (5)	0.60476 (4)	0.27703 (5)	0.1296 (2)
C19	0.50581 (4)	0.33806 (4)	−0.25318 (4)	0.08791 (19)
C20	0.45778 (5)	0.42592 (4)	−0.23635 (4)	0.0964 (2)
C22	0.22977 (6)	0.48921 (6)	−0.35787 (6)	0.1714 (3)
H7	1.19309	0.14961	0.33454	0.06647*
H8	1.08956	0.00288	0.32917	0.07562*
H9	0.80819	0.02020	0.12828	0.07655*
H10	0.62756	0.18197	−0.06891	0.06241*
H11	0.87682	0.68092	−0.01271	0.05863*
H13	1.09047	0.84869	0.20769	0.07099*
H14	1.36840	0.93537	0.43985	0.080093*
H15	1.58469	0.81455	0.56695	0.07539*
H16	1.52493	0.61204	0.46216	0.07622*
H17	1.25024	0.51975	0.23580	0.06937*
H19A	0.47758	0.24310	−0.26795	0.05483*
H19B	0.44504	0.36920	−0.34030	0.05483*
H22A	0.11103	0.47109	−0.45079	0.08854*
H22B	0.24685	0.58634	−0.35125	0.08854*
H22C	0.28896	0.46210	−0.27104	0.08854*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
S1	0.04021 (5)	0.04332 (5)	0.05670 (6)	0.01102 (5)	0.04374 (5)	0.01255 (5)
O18	0.03424 (14)	0.04846 (16)	0.04335 (16)	0.01059 (12)	0.03267 (14)	0.01335 (13)
O21	0.03301 (14)	0.06142 (17)	0.04817 (16)	−0.00212 (13)	0.03505 (14)	−0.00472 (14)
O23	0.04515 (17)	0.0714 (2)	0.05273 (18)	−0.01135 (15)	0.04282 (17)	−0.01989 (16)
N4	0.02654 (14)	0.03747 (16)	0.03242 (15)	0.00039 (13)	0.02529 (14)	0.00022 (14)
C2	0.03119 (18)	0.03952 (19)	0.03592 (19)	0.00418 (15)	0.03002 (18)	0.00356 (16)
C3	0.03300 (19)	0.03637 (19)	0.0374 (2)	0.00339 (16)	0.03137 (19)	0.00170 (17)
C5	0.03325 (19)	0.03168 (18)	0.03361 (19)	−0.00152 (15)	0.02965 (18)	−0.00345 (15)
C6	0.0372 (2)	0.03568 (19)	0.0413 (2)	0.00303 (16)	0.0355 (2)	0.00130 (16)
C7	0.0419 (2)	0.0514 (2)	0.0473 (2)	0.01310 (19)	0.0397 (2)	0.0136 (2)
C8	0.0583 (3)	0.0540 (3)	0.0558 (3)	0.0135 (2)	0.0520 (3)	0.0158 (2)
C9	0.0607 (3)	0.0488 (2)	0.0592 (3)	−0.0018 (2)	0.0556 (3)	0.0013 (2)
C10	0.0399 (2)	0.0444 (2)	0.0438 (2)	−0.00542 (18)	0.0377 (2)	−0.00572 (19)
C11	0.03584 (19)	0.0409 (2)	0.0404 (2)	0.00410 (16)	0.03399 (19)	0.00501 (17)
C12	0.03836 (19)	0.0404 (2)	0.0406 (2)	0.00032 (16)	0.03590 (19)	0.00306 (17)
C13	0.0515 (2)	0.0419 (2)	0.0607 (3)	−0.00263 (18)	0.0511 (2)	−0.0011 (2)
C14	0.0634 (3)	0.0500 (2)	0.0674 (3)	−0.0168 (2)	0.0590 (3)	−0.0153 (2)
C15	0.0452 (3)	0.0653 (3)	0.0573 (3)	−0.0153 (2)	0.0438 (3)	−0.0098 (2)
C16	0.0439 (2)	0.0618 (3)	0.0634 (3)	0.0013 (2)	0.0478 (2)	0.0047 (2)
C17	0.0468 (2)	0.0483 (2)	0.0544 (2)	−0.00173 (18)	0.0468 (2)	−0.00038 (19)
C19	0.02806 (17)	0.0434 (2)	0.03322 (18)	−0.00383 (17)	0.02569 (17)	−0.00434 (18)
C20	0.03260 (18)	0.0408 (2)	0.0386 (2)	−0.00042 (16)	0.03126 (19)	0.00180 (18)
C22	0.0538 (3)	0.0841 (3)	0.0730 (3)	0.0096 (2)	0.0581 (3)	0.0054 (3)

Geometric parameters (Å, º)

S1—C2	1.7534 (5)	C6—C7	1.3894 (5)
S1—C6	1.7532 (11)	C7—C8	1.3729 (16)
O18—C3	1.2245 (4)	C8—C9	1.3748 (14)
O21—C20	1.3330 (9)	C9—C10	1.3827 (5)
O21—C22	1.4501 (16)	C11—C12	1.4652 (5)
O23—C20	1.1968 (5)	C12—C13	1.3914 (5)
N4—C3	1.3744 (9)	C12—C17	1.3868 (13)
N4—C5	1.4231 (4)	C13—C14	1.3831 (5)
N4—C19	1.4642 (9)	C14—C15	1.3745 (17)
C2—C3	1.4898 (5)	C15—C16	1.3721 (7)
C2—C11	1.3368 (5)	C16—C17	1.3853 (6)
C5—C6	1.3990 (11)	C19—C20	1.5060 (14)
C5—C10	1.3909 (14)
C2—S1—C6	99.27 (2)	C6—C7—C8	121.00 (4)
C20—O21—C22	116.02 (3)	C7—C8—C9	119.31 (4)
C3—N4—C5	124.92 (3)	C8—C9—C10	120.69 (10)
C3—N4—C19	114.65 (3)	C5—C10—C9	120.64 (4)
C5—N4—C19	118.70 (3)	C2—C11—C12	129.15 (3)
S1—C2—C3	117.93 (3)	C11—C12—C13	117.40 (8)
S1—C2—C11	124.46 (3)	C11—C12—C17	124.14 (3)
C3—C2—C11	117.60 (3)	C13—C12—C17	118.41 (3)
O18—C3—N4	120.53 (3)	C12—C13—C14	121.03 (9)
O18—C3—C2	120.49 (3)	C13—C14—C15	119.57 (4)
N4—C3—C2	118.97 (3)	C14—C15—C16	120.19 (4)
N4—C5—C6	120.37 (8)	C15—C16—C17	120.43 (10)
N4—C5—C10	121.21 (3)	C12—C17—C16	120.25 (4)
C6—C5—C10	118.41 (3)	N4—C19—C20	111.46 (3)
S1—C6—C5	122.23 (3)	O21—C20—O23	124.34 (10)
S1—C6—C7	117.89 (7)	O21—C20—C19	110.06 (3)
C5—C6—C7	119.87 (9)	O23—C20—C19	125.60 (8)