2-(4-Bromo­phen­yl)-5,7-dimeth­yl[1,3]oxazolo[3,2-a]pyrimidin-4-ium perchlorate

The title compound, C₁₄H₁₂BrN₂O⁺·ClO₄^-, was synthesized from the parent 2-amino­oxazole and acetyl­acetone and characterized by ¹H NMR and single-crystal X-ray diffraction. The bromo­phenyl fragment and the essentially planar nine-membered bicyclic system form a dihedral angle of 10.50 (11)°.

Key indicators

• Single-crystal X-ray study
• T = 293 K
• Mean [sigma](C-C) = 0.006 Å
• R factor = 0.045
• wR factor = 0.115
• Data-to-parameter ratio = 14.7

checkCIF/PLATON results

No syntax errors found



Alert level A
PLAT029_ALERT_3_A _diffrn_measured_fraction_theta_full Low .......       0.93

Alert level B
PLAT431_ALERT_2_B Short Inter HL..A Contact  Br13   ..  O13     ..       2.99 Ang.
PLAT432_ALERT_2_B Short Inter X...Y Contact  O13    ..  C5      ..       2.84 Ang.

Alert level C
REFLT03_ALERT_3_C  Reflection count < 95% complete
           From the CIF: _diffrn_reflns_theta_max           75.00
           From the CIF: _diffrn_reflns_theta_full          75.00
           From the CIF: _reflns_number_total               3090
           TEST2: Reflns within _diffrn_reflns_theta_max
           Count of symmetry unique reflns         3332
           Completeness (_total/calc)             92.74%
PLAT022_ALERT_3_C Ratio Unique / Expected Reflections too Low ....       0.93
PLAT230_ALERT_2_C Hirshfeld Test Diff for    C3     -   C10     ..       5.97 su
PLAT244_ALERT_4_C Low   'Solvent' Ueq as Compared to Neighbors for        Cl1
PLAT432_ALERT_2_C Short Inter X...Y Contact  O11    ..  C9      ..       2.96 Ang.

Alert level G
PLAT199_ALERT_1_G Check the Reported _cell_measurement_temperature        293 K
PLAT200_ALERT_1_G Check the Reported _diffrn_ambient_temperature .        293 K

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

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

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Computing details

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

2-(4-Bromophenyl)-5,7-dimethyl[1,3]oxazolo[3,2-a]pyrimidin-4-ium perchlorate

Crystal data

C14H12BrN2O^+·ClO4^−	F(000) = 808
Mr = 403.62	Dx = 1.660 Mg m^−3
Monoclinic, P21/c	Melting point: 589 K
Hall symbol: -P 2ybc	Cu Kα radiation, λ = 1.5418 Å
a = 15.742 (4) Å	Cell parameters from 25 reflections
b = 13.292 (4) Å	θ = 30–32°
c = 7.718 (3) Å	µ = 5.25 mm^−1
β = 91.14 (2)°	T = 293 K
V = 1614.6 (9) Å^3	Block, colourless
Z = 4	0.15 × 0.15 × 0.15 mm

Data collection

Enraf–Nonius CAD-4 diffractometer	Rint = 0.025
Radiation source: Fine-focus sealed tube	θmax = 75.0°, θmin = 2.8°
Graphite monochromator	h = −19→19
ω scans	k = 0→16
3354 measured reflections	l = 0→9
3090 independent reflections	1 standard reflections every 60 min
1986 reflections with I > 2σ(I)	intensity decay: 7%

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)] = 0.045	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.115	H-atom parameters constrained
S = 0.96	w = 1/[σ^2(Fo^2) + (0.056P)^2] where P = (Fo^2 + 2Fc^2)/3
3090 reflections	(Δ/σ)max = 0.001
210 parameters	Δρmax = 0.35 e Å^−3
0 restraints	Δρmin = −0.31 e Å^−3

Special details

Experimental. NMR ¹H (DMSO-d₆/TMS) δ, J (Hz) 9.46 (s, 1H, H-3), 7.97 (m, 3H, (2H, p-BrPh + H-6)), 7.83 (m, 2H, p-BrPh), 2.91 (s, 3H, 5-CH₃), 2.84 (s, 3H, 7-CH₃).

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

	x	y	z	Uiso*/Ueq
N1	0.79574 (18)	0.0765 (2)	−0.1354 (4)	0.0460 (7)
C2	0.7566 (2)	0.1672 (3)	−0.0885 (5)	0.0488 (9)
H2	0.7818	0.2303	−0.0794	0.059*
C3	0.6752 (2)	0.1439 (3)	−0.0598 (5)	0.0489 (9)
O4	0.66243 (15)	0.0418 (2)	−0.0894 (3)	0.0545 (7)
C5	0.7370 (2)	0.0036 (3)	−0.1345 (5)	0.0498 (9)
N6	0.7477 (2)	−0.0908 (2)	−0.1702 (5)	0.0592 (9)
C7	0.8276 (3)	−0.1156 (3)	−0.2091 (5)	0.0631 (11)
C71	0.8421 (3)	−0.2229 (4)	−0.2622 (7)	0.0866 (16)
H71A	0.8546	−0.2629	−0.1613	0.130*
H71B	0.8890	−0.2260	−0.3395	0.130*
H71C	0.7919	−0.2484	−0.3198	0.130*
C8	0.8933 (3)	−0.0443 (4)	−0.2074 (5)	0.0601 (11)
H8	0.9483	−0.0649	−0.2312	0.072*
C9	0.8787 (2)	0.0534 (3)	−0.1720 (5)	0.0548 (10)
C91	0.9411 (2)	0.1366 (4)	−0.1719 (6)	0.0668 (12)
H91A	0.9445	0.1663	−0.0586	0.100*
H91B	0.9235	0.1865	−0.2549	0.100*
H91C	0.9958	0.1109	−0.2020	0.100*
C10	0.6026 (2)	0.2032 (3)	−0.0045 (5)	0.0484 (9)
C11	0.5284 (2)	0.1561 (4)	0.0441 (6)	0.0675 (12)
H11	0.5251	0.0863	0.0416	0.081*
C12	0.4589 (2)	0.2115 (4)	0.0964 (6)	0.0661 (12)
H12	0.4093	0.1798	0.1304	0.079*
C13	0.4653 (2)	0.3145 (4)	0.0967 (6)	0.0598 (11)
Br13	0.37035 (3)	0.39295 (4)	0.16018 (8)	0.0827 (2)
C14	0.5393 (3)	0.3633 (4)	0.0515 (6)	0.0660 (12)
H14	0.5428	0.4330	0.0568	0.079*
C15	0.6082 (2)	0.3071 (3)	−0.0017 (6)	0.0595 (11)
H15	0.6578	0.3390	−0.0352	0.071*
Cl1	0.84530 (6)	0.04819 (8)	0.33257 (13)	0.0558 (3)
O11	0.8082 (3)	0.0957 (3)	0.4764 (4)	0.1070 (14)
O12	0.8970 (3)	−0.0307 (4)	0.3935 (5)	0.1232 (16)
O13	0.7803 (3)	0.0099 (4)	0.2244 (5)	0.140 (2)
O14	0.8925 (3)	0.1175 (3)	0.2328 (5)	0.1073 (13)

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
N1	0.0582 (15)	0.0509 (19)	0.0288 (17)	0.0037 (13)	−0.0058 (13)	0.0022 (14)
C2	0.0622 (19)	0.042 (2)	0.042 (2)	0.0032 (16)	−0.0089 (17)	−0.0056 (18)
C3	0.0653 (19)	0.047 (2)	0.033 (2)	−0.0006 (17)	−0.0098 (17)	0.0025 (18)
O4	0.0646 (14)	0.0476 (16)	0.0511 (17)	0.0012 (12)	−0.0053 (12)	−0.0031 (14)
C5	0.0626 (19)	0.055 (2)	0.032 (2)	0.0013 (17)	−0.0074 (16)	0.0004 (19)
N6	0.082 (2)	0.045 (2)	0.051 (2)	0.0011 (16)	−0.0010 (17)	−0.0045 (17)
C7	0.091 (3)	0.061 (3)	0.037 (3)	0.016 (2)	0.000 (2)	0.002 (2)
C71	0.111 (4)	0.063 (3)	0.087 (4)	0.016 (3)	0.014 (3)	−0.017 (3)
C8	0.078 (2)	0.067 (3)	0.036 (2)	0.021 (2)	0.0028 (19)	0.009 (2)
C9	0.070 (2)	0.066 (3)	0.028 (2)	0.0098 (19)	−0.0011 (17)	0.012 (2)
C91	0.061 (2)	0.073 (3)	0.067 (3)	0.004 (2)	0.003 (2)	0.008 (3)
C10	0.0524 (17)	0.052 (2)	0.041 (2)	0.0090 (16)	−0.0065 (16)	0.0010 (19)
C11	0.068 (2)	0.056 (3)	0.079 (3)	−0.0069 (19)	0.005 (2)	−0.012 (2)
C12	0.062 (2)	0.063 (3)	0.073 (3)	−0.0029 (19)	0.005 (2)	−0.007 (3)
C13	0.0589 (19)	0.068 (3)	0.052 (3)	0.0128 (19)	−0.0040 (18)	0.000 (2)
Br13	0.0708 (3)	0.0805 (4)	0.0972 (5)	0.0196 (2)	0.0086 (3)	−0.0018 (3)
C14	0.073 (2)	0.054 (3)	0.071 (3)	0.0089 (19)	0.003 (2)	0.010 (2)
C15	0.0564 (18)	0.053 (3)	0.069 (3)	0.0008 (17)	−0.0058 (19)	0.009 (2)
Cl1	0.0673 (5)	0.0613 (6)	0.0386 (6)	0.0022 (4)	−0.0063 (4)	0.0021 (5)
O11	0.155 (3)	0.115 (3)	0.051 (2)	0.062 (3)	0.010 (2)	0.001 (2)
O12	0.168 (4)	0.127 (4)	0.075 (3)	0.073 (3)	0.009 (3)	0.011 (3)
O13	0.153 (3)	0.198 (5)	0.068 (3)	−0.104 (4)	−0.036 (2)	0.048 (3)
O14	0.120 (3)	0.119 (3)	0.082 (3)	−0.045 (2)	0.000 (2)	0.011 (2)

Geometric parameters (Å, º)

N1—C5	1.339 (5)	C91—H91A	0.96
N1—C9	1.376 (4)	C91—H91B	0.96
N1—C2	1.406 (4)	C91—H91C	0.96
C2—C3	1.341 (5)	C10—C11	1.383 (5)
C2—H2	0.93	C10—C15	1.385 (5)
C3—O4	1.390 (5)	C11—C12	1.385 (6)
C3—C10	1.458 (5)	C11—H11	0.93
O4—C5	1.331 (4)	C12—C13	1.373 (6)
C5—N6	1.296 (5)	C12—H12	0.93
N6—C7	1.341 (5)	C13—C14	1.384 (6)
C7—C8	1.403 (6)	C13—Br13	1.895 (4)
C7—C71	1.502 (6)	C14—C15	1.385 (5)
C71—H71A	0.96	C14—H14	0.93
C71—H71B	0.96	C15—H15	0.93
C71—H71C	0.96	Cl1—O13	1.403 (4)
C8—C9	1.348 (6)	Cl1—O12	1.403 (4)
C8—H8	0.93	Cl1—O11	1.414 (3)
C9—C91	1.478 (6)	Cl1—O14	1.420 (4)
C5—N1—C9	119.9 (3)	C9—C91—H91B	109.5
C5—N1—C2	108.2 (3)	H91A—C91—H91B	109.5
C9—N1—C2	131.8 (3)	C9—C91—H91C	109.5
C3—C2—N1	105.6 (3)	H91A—C91—H91C	109.5
C3—C2—H2	127.2	H91B—C91—H91C	109.5
N1—C2—H2	127.2	C11—C10—C15	120.0 (4)
C2—C3—O4	109.5 (3)	C11—C10—C3	120.4 (4)
C2—C3—C10	132.9 (4)	C15—C10—C3	119.6 (3)
O4—C3—C10	117.6 (3)	C10—C11—C12	121.0 (4)
C5—O4—C3	106.8 (3)	C10—C11—H11	119.5
N6—C5—O4	122.9 (3)	C12—C11—H11	119.5
N6—C5—N1	127.3 (4)	C13—C12—C11	118.2 (4)
O4—C5—N1	109.8 (3)	C13—C12—H12	120.9
C5—N6—C7	114.4 (4)	C11—C12—H12	120.9
N6—C7—C8	121.8 (4)	C12—C13—C14	121.9 (4)
N6—C7—C71	116.3 (4)	C12—C13—Br13	119.4 (3)
C8—C7—C71	121.9 (4)	C14—C13—Br13	118.7 (3)
C7—C71—H71A	109.5	C13—C14—C15	119.4 (4)
C7—C71—H71B	109.5	C13—C14—H14	120.3
H71A—C71—H71B	109.5	C15—C14—H14	120.3
C7—C71—H71C	109.5	C10—C15—C14	119.5 (4)
H71A—C71—H71C	109.5	C10—C15—H15	120.2
H71B—C71—H71C	109.5	C14—C15—H15	120.2
C9—C8—C7	121.6 (4)	O13—Cl1—O12	109.9 (3)
C9—C8—H8	119.2	O13—Cl1—O11	108.7 (3)
C7—C8—H8	119.2	O12—Cl1—O11	108.5 (2)
C8—C9—N1	115.0 (4)	O13—Cl1—O14	107.2 (2)
C8—C9—C91	127.2 (4)	O12—Cl1—O14	111.1 (3)
N1—C9—C91	117.8 (4)	O11—Cl1—O14	111.4 (3)
C9—C91—H91A	109.5

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2···O11^i	0.93	2.39	3.290 (6)	164
C11—H11···O4	0.93	2.48	2.812 (5)	101
C15—H15···O11^i	0.93	2.52	3.411 (6)	160
C91—H91A···O14	0.96	2.49	3.241 (6)	135
C91—H91C···O12^ii	0.96	2.50	3.402 (6)	156

Symmetry codes: (i) x, −y+1/2, z−1/2; (ii) −x+2, −y, −z.