5-(4-Chloro­phen­yl)-6-ethoxy­carbonyl-3,7-dimethyl-5H-thia­zolo[3,2-a]pyrimidin-8-ium bromide

In the title salt, C₁₇H₁₈ClN₂O₂S⁺·Br^-, the benzene ring is roughly perpendicular to the heterocyclic ring system.

Key indicators

• Single-crystal X-ray study
• T = 291 K
• Mean [sigma](C-C) = 0.005 Å
• R factor = 0.044
• wR factor = 0.094
• Data-to-parameter ratio = 17.9

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT431_ALERT_2_C Short Inter HL..A Contact  Br1    ..  S1      ..       3.59 Ang.

Alert level G
PLAT793_ALERT_1_G Check the Absolute Configuration of C7     = ...          S

   0 ALERT level A = In general: serious problem
   0 ALERT level B = Potentially serious problem
   1 ALERT level C = Check and explain
   1 ALERT level G = General alerts; check

   1 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   1 ALERT type 2 Indicator that the structure model may be wrong or deficient
   0 ALERT type 3 Indicator that the structure quality may be low
   0 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

A number of thiazolo[3,2-a]pyrimidine derivatives have been reported in the literature. These heterocyclic compounds are pharmacologically interesting systems with remarkable biological activities such as anti-inflammatory, anti-cancer and anti-microbial properties (Tozkoparan et al., 1998; Holla et al., 2004; Sayed et al., 2006).

The structure of the newly synthesized compound, (I), was confirmed by its elemental analysis, and by IR, NMR and mass spectroscopic studies. The crystallographic analysis (Fig. 1) shows the aryl and oxazolidine rings to be essentially co-planar

Related literature

For synthesis, see Ranu et al. (2002). For related literature, see: Holla et al. (2004); Sayed et al. (2006); Tozkoparan et al. (1998).

S2. Experimental

Ethyl 5-(4-chlorophenyl)-3,7-dimethyl-5H-thiazolo[3,2-a]pyrimidine-6-carboxylate was prepared according to the literature method (Ranu et al., 2002). This compound (1 mmol) and 1-bromopropan-2-one (1 mmol) were successively added to water (5 ml) in a test tube and the reaction mixture was vigorously refluxed for 24 h. The system was cooled to room temperature and filtered to isolate the crude product. The analytical sample was obtained by recrystallization of the crude product from ethanol. The solid was isolated, washed three times with ethanol and dried in a vacuum desiccator; yield 92%, m.p. 513–514 K. IR: 3110, 2980, 1688, 1630, 1600, 1511, 1500 cm^-1; ¹H NMR: 1.22 (t, J = 7.2 Hz, 3H), 2.00 (s, 3H), 2.55 (s, 3H), 4.10–4.21 (m, 2H), 6.27 (s, 1H), 7.10 (s, 1H), 7.14–7.24 (m, 2H), 7.26–7.29 p.p.m. (m, 2H). Analysis found: C 47.51, H 4.22, N 6.52%; C₁₇H₁₈BrN₂O₂S requires: C 47.60, H 4.29, N 6.48%. Single crystals suitable for crystallography were obtained by the slow evaporation of an ethanol solution of (I).

S3. Refinement

The H atom bonded to N atom was located in a difference map and refined with U_iso(H) = 1.2U_eq(N) so that N—H = 0.86 (1) Å. Other H atoms were positioned geometrically and refined using a riding model approximation with C—H = 0.93–0.98 Å and with U_iso(H) = 1.2–1.5U_eq(C).

Computing details

Data collection: SMART (Bruker, 2000); cell refinement: SMART (Bruker, 2000); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXTL (Bruker, 2000); program(s) used to refine structure: SHELXTL (Bruker, 2000); molecular graphics: SHELXTL (Bruker, 2000); software used to prepare material for publication: SHELXTL (Bruker, 2000).

Figures

Fig. 1. The molecular structure of (I), showing the atom-numbering scheme and 30% probability displacement ellipsoids.

5-(4-Chlorophenyl)-6-ethoxycarbonyl-3,7-dimethyl-5H- thiazolo[3,2-a]pyrimidin-8-ium bromide

Crystal data

C17H18ClN2O2S^+·Br^−	F(000) = 1744
Mr = 429.75	Dx = 1.407 Mg m^−3
Monoclinic, C2/c	Melting point = 513–514 K
Hall symbol: -C 2yc	Mo Kα radiation, λ = 0.71073 Å
a = 25.457 (2) Å	Cell parameters from 2973 reflections
b = 11.697 (2) Å	θ = 2.3–25.5°
c = 14.231 (3) Å	µ = 2.27 mm^−1
β = 106.8080 (16)°	T = 291 K
V = 4056.5 (12) Å^3	Block, colourless
Z = 8	0.30 × 0.26 × 0.24 mm

Data collection

Bruker SMART APEX CCD diffractometer	3986 independent reflections
Radiation source: sealed tube	2937 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.031
ϕ and ω scans	θmax = 26.0°, θmin = 1.7°
Absorption correction: multi-scan (SADABS; Bruker, 2000)	h = −29→31
Tmin = 0.505, Tmax = 0.584	k = −14→13
10641 measured reflections	l = −17→16

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)] = 0.044	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.094	H atoms treated by a mixture of independent and constrained refinement
S = 1.04	w = 1/[σ^2(Fo^2) + (0.0421P)^2 + 1.5186P] where P = (Fo^2 + 2Fc^2)/3
3986 reflections	(Δ/σ)max < 0.001
223 parameters	Δρmax = 0.26 e Å^−3
0 restraints	Δρmin = −0.29 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
Br1	0.193130 (15)	0.08363 (3)	0.11668 (3)	0.06287 (14)
C1	0.05124 (13)	0.2550 (3)	0.5811 (2)	0.0529 (8)
C2	0.00250 (15)	0.2082 (3)	0.5272 (3)	0.0606 (9)
H2	0.0025	0.1379	0.4966	0.073*
C3	−0.04725 (15)	0.2644 (3)	0.5177 (3)	0.0681 (10)
H3	−0.0803	0.2330	0.4808	0.082*
C4	−0.04561 (15)	0.3696 (3)	0.5654 (3)	0.0621 (9)
C5	0.00383 (16)	0.4186 (3)	0.6183 (3)	0.0685 (10)
H5	0.0042	0.4902	0.6469	0.082*
C6	0.05217 (14)	0.3609 (3)	0.6283 (3)	0.0603 (9)
H6	0.0853	0.3916	0.6659	0.072*
C7	0.10663 (12)	0.1866 (3)	0.5932 (2)	0.0456 (7)
H7	0.0983	0.1127	0.5597	0.055*
C8	0.14678 (12)	0.2529 (3)	0.5513 (2)	0.0467 (7)
C9	0.19109 (13)	0.3174 (3)	0.6071 (2)	0.0527 (8)
S1	0.19598 (4)	0.18989 (8)	0.88153 (6)	0.0567 (2)
C10	0.17799 (13)	0.2276 (3)	0.7561 (2)	0.0530 (8)
C11	0.14183 (14)	0.0864 (3)	0.8572 (3)	0.0602 (9)
H11	0.1333	0.0420	0.9050	0.072*
C12	0.11427 (14)	0.0811 (3)	0.7576 (3)	0.0560 (8)
C13	0.06841 (13)	0.0014 (3)	0.7070 (3)	0.0637 (10)
H13A	0.0659	−0.0591	0.7511	0.096*
H13B	0.0756	−0.0303	0.6498	0.096*
H13C	0.0344	0.0429	0.6880	0.096*
C14	0.23141 (13)	0.3942 (3)	0.5837 (3)	0.0580 (9)
H14A	0.2168	0.4228	0.5180	0.087*
H14B	0.2647	0.3528	0.5886	0.087*
H14C	0.2391	0.4570	0.6290	0.087*
C15	0.13101 (13)	0.2443 (3)	0.4422 (2)	0.0489 (7)
C16	0.14414 (14)	0.3068 (3)	0.2878 (2)	0.0578 (8)
H16A	0.1052	0.3235	0.2631	0.069*
H16B	0.1504	0.2310	0.2656	0.069*
C17	0.17647 (16)	0.3939 (3)	0.2484 (3)	0.0656 (10)
H17C	0.2148	0.3753	0.2708	0.098*
H17D	0.1707	0.4687	0.2715	0.098*
H17E	0.1643	0.3930	0.1780	0.098*
Cl1	−0.10751 (4)	0.44589 (8)	0.55951 (7)	0.0653 (2)
N1	0.20339 (11)	0.3071 (3)	0.7143 (2)	0.0524 (7)
H1A	0.2272 (15)	0.352 (3)	0.751 (3)	0.063*
N2	0.13435 (11)	0.1668 (2)	0.70220 (18)	0.0512 (6)
O1	0.09178 (10)	0.1876 (2)	0.39502 (17)	0.0640 (6)
O2	0.16151 (9)	0.31004 (19)	0.39710 (16)	0.0576 (6)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0658 (2)	0.0651 (2)	0.0608 (2)	0.02571 (17)	0.02317 (17)	0.01386 (17)
C1	0.058 (2)	0.063 (2)	0.0365 (16)	0.0073 (16)	0.0130 (14)	0.0039 (15)
C2	0.066 (2)	0.0456 (18)	0.062 (2)	−0.0010 (16)	0.0062 (18)	−0.0170 (16)
C3	0.056 (2)	0.063 (2)	0.071 (2)	−0.0100 (17)	−0.0033 (18)	−0.0028 (19)
C4	0.067 (2)	0.057 (2)	0.063 (2)	0.0246 (17)	0.0194 (18)	0.0080 (18)
C5	0.071 (2)	0.066 (2)	0.076 (2)	0.0059 (18)	0.032 (2)	−0.016 (2)
C6	0.0563 (19)	0.0502 (19)	0.067 (2)	0.0073 (16)	0.0069 (16)	−0.0057 (17)
C7	0.0529 (17)	0.0482 (17)	0.0347 (15)	0.0020 (13)	0.0110 (13)	−0.0028 (13)
C8	0.0483 (17)	0.0397 (16)	0.0513 (17)	0.0009 (13)	0.0130 (14)	0.0051 (13)
C9	0.0566 (18)	0.0418 (17)	0.0519 (18)	0.0098 (14)	0.0037 (15)	0.0119 (14)
S1	0.0619 (5)	0.0638 (5)	0.0379 (4)	0.0063 (4)	0.0039 (4)	−0.0014 (4)
C10	0.0530 (18)	0.0535 (19)	0.0436 (17)	0.0054 (15)	0.0000 (14)	0.0027 (14)
C11	0.059 (2)	0.055 (2)	0.067 (2)	0.0177 (16)	0.0182 (17)	0.0049 (17)
C12	0.060 (2)	0.0515 (19)	0.056 (2)	−0.0008 (15)	0.0154 (16)	0.0025 (15)
C13	0.0506 (19)	0.061 (2)	0.075 (2)	−0.0112 (16)	0.0112 (17)	0.0335 (18)
C14	0.0406 (17)	0.064 (2)	0.063 (2)	0.0054 (14)	0.0052 (15)	0.0018 (17)
C15	0.0542 (18)	0.0412 (16)	0.0512 (17)	0.0069 (14)	0.0153 (15)	−0.0062 (14)
C16	0.0500 (18)	0.074 (2)	0.0516 (19)	0.0026 (16)	0.0178 (15)	0.0031 (17)
C17	0.078 (2)	0.062 (2)	0.062 (2)	0.0046 (18)	0.0274 (19)	0.0238 (18)
Cl1	0.0674 (5)	0.0663 (6)	0.0663 (5)	0.0288 (4)	0.0256 (4)	0.0153 (4)
N1	0.0506 (16)	0.0581 (17)	0.0463 (15)	−0.0042 (12)	0.0104 (12)	−0.0016 (13)
N2	0.0575 (16)	0.0523 (16)	0.0432 (15)	0.0045 (12)	0.0137 (12)	0.0031 (12)
O1	0.0707 (15)	0.0666 (16)	0.0556 (14)	−0.0212 (12)	0.0198 (12)	−0.0160 (12)
O2	0.0584 (14)	0.0594 (14)	0.0568 (14)	0.0008 (11)	0.0193 (11)	0.0104 (11)

Geometric parameters (Å, º)

C1—C2	1.370 (5)	C10—N1	1.363 (4)
C1—C6	1.405 (5)	C11—C12	1.389 (5)
C1—C7	1.587 (4)	C11—H11	0.9300
C2—C3	1.398 (5)	C12—N2	1.456 (4)
C2—H2	0.9300	C12—C13	1.505 (5)
C3—C4	1.401 (5)	C13—H13A	0.9600
C3—H3	0.9300	C13—H13B	0.9600
C4—C5	1.389 (5)	C13—H13C	0.9600
C4—Cl1	1.791 (3)	C14—H14A	0.9600
C5—C6	1.375 (5)	C14—H14B	0.9600
C5—H5	0.9300	C14—H14C	0.9600
C6—H6	0.9300	C15—O1	1.225 (4)
C7—N2	1.524 (4)	C15—O2	1.376 (4)
C7—C8	1.534 (4)	C16—O2	1.489 (4)
C7—H7	0.9800	C16—C17	1.516 (5)
C8—C9	1.398 (4)	C16—H16A	0.9700
C8—C15	1.492 (4)	C16—H16B	0.9700
C9—N1	1.471 (4)	C17—H17C	0.9600
C9—C14	1.473 (5)	C17—H17D	0.9600
S1—C10	1.766 (3)	C17—H17E	0.9600
S1—C11	1.792 (4)	N1—H1A	0.86 (4)
C10—N2	1.355 (4)
C2—C1—C6	120.5 (3)	C11—C12—N2	111.7 (3)
C2—C1—C7	119.5 (3)	C11—C12—C13	127.5 (3)
C6—C1—C7	120.0 (3)	N2—C12—C13	120.8 (3)
C1—C2—C3	121.0 (3)	C12—C13—H13A	109.5
C1—C2—H2	119.5	C12—C13—H13B	109.5
C3—C2—H2	119.5	H13A—C13—H13B	109.5
C2—C3—C4	117.8 (3)	C12—C13—H13C	109.5
C2—C3—H3	121.1	H13A—C13—H13C	109.5
C4—C3—H3	121.1	H13B—C13—H13C	109.5
C5—C4—C3	121.3 (3)	C9—C14—H14A	109.5
C5—C4—Cl1	117.9 (3)	C9—C14—H14B	109.5
C3—C4—Cl1	120.8 (3)	H14A—C14—H14B	109.5
C6—C5—C4	119.8 (3)	C9—C14—H14C	109.5
C6—C5—H5	120.1	H14A—C14—H14C	109.5
C4—C5—H5	120.1	H14B—C14—H14C	109.5
C5—C6—C1	119.5 (3)	O1—C15—O2	121.9 (3)
C5—C6—H6	120.3	O1—C15—C8	122.6 (3)
C1—C6—H6	120.3	O2—C15—C8	115.4 (3)
N2—C7—C8	107.9 (2)	O2—C16—C17	109.9 (3)
N2—C7—C1	108.8 (2)	O2—C16—H16A	109.7
C8—C7—C1	111.9 (2)	C17—C16—H16A	109.7
N2—C7—H7	109.4	O2—C16—H16B	109.7
C8—C7—H7	109.4	C17—C16—H16B	109.7
C1—C7—H7	109.4	H16A—C16—H16B	108.2
C9—C8—C15	123.9 (3)	C16—C17—H17C	109.5
C9—C8—C7	124.8 (3)	C16—C17—H17D	109.5
C15—C8—C7	111.2 (3)	H17C—C17—H17D	109.5
C8—C9—N1	116.1 (3)	C16—C17—H17E	109.5
C8—C9—C14	134.5 (3)	H17C—C17—H17E	109.5
N1—C9—C14	109.4 (3)	H17D—C17—H17E	109.5
C10—S1—C11	90.78 (17)	C10—N1—C9	121.5 (3)
N2—C10—N1	121.7 (3)	C10—N1—H1A	119 (2)
N2—C10—S1	111.8 (2)	C9—N1—H1A	119 (2)
N1—C10—S1	126.5 (2)	C10—N2—C12	114.4 (3)
C12—C11—S1	111.1 (3)	C10—N2—C7	124.0 (3)
C12—C11—H11	124.4	C12—N2—C7	121.6 (3)
S1—C11—H11	124.4	C15—O2—C16	115.8 (2)