Methyl 7-(4-bromo­phen­yl)-5-methyl-4,7-dihydro­tetra­zolo[1,5-a]pyrimidine-6-carboxyl­ate

The title compound, C₁₃H₁₂BrN₅O₂, was obtained by the solid-state reaction of 4-bromo­benzaldehyde, 1H-tetra­zol-5-amine hydrate and methyl acetoacetate catalysed by sulfamic acid. The pyrimidine ring adopts a flattened boat conformation. In the crystal structure, centrosymmetrically related mol­ecules are linked into dimers by inter­molecular N—H...N hydrogen bonds.

Key indicators

• Single-crystal X-ray study
• T = 113 K
• Mean [sigma](C-C) = 0.003 Å
• R factor = 0.035
• wR factor = 0.083
• Data-to-parameter ratio = 16.6

checkCIF/PLATON results

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Alert level C
PLAT062_ALERT_4_C Rescale T(min) & T(max) by .....................       0.98

Alert level G
PLAT793_ALERT_1_G Check the Absolute Configuration of C1     = ...          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
   0 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
   1 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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S1. Comment

As the analogs of purine, the derivatives of dihydrotetrazolo[1,5-a] pyrimidine are reported to have various biological activities, such as antimicrobial (Ali, 2006), farnesyl transferase inhibitory (Lansbury & Liu, 2006), antihypertensive (Ismail et al., 2002) acrivities, etc. This led us to pay more attention to the synthesis and structure determination of these compounds. To further study the relationship between the structure and bioactivity, we synthesized a series of dihydrotetrazolo[1,5-a]pyrimidine derivatives. We report here the crystal structure of the title compound.

The molecular structure of the title compound is shown in Fig. 1. The pyrimidine ring adopts a flattened-boat conformation, with atoms N5 and C1 deviating from the N1/C2/C3/C4 plane by 0.118 (4) Å and 0.175 (4) Å, respectively. The N1—N4/C2 and C5—C10 planes form dihedral angles of 9.56 (17)° and 86.95 (7)°, respectively, with the N1/C2/C3/C4 plane.

In the crystal structure, inversion-related molecules are linked to form a dimer by N—H···N hydrogen bonds (Fig.2 and Table 2).

Related literature

For thebiological activities of dihydrotetrazolo[1,5-a]pyrimidines, see: Ali (2006); Ismail et al. (2002); Lansbury & Liu (2006).

S2. Experimental

The title compound was synthesized by solid-state reaction of 4-bromobenzaldehyde, 1H-tetrazol-5-amine hydrate and methyl acetoacetate in a 1:1:1 molar ratio, catalyzed by sulfamic acid at 363 K. After cooling, the reaction mixture was washed with water and recrystallized from ethanol, giving single crystals suitable for X-ray diffraction.

S3. Refinement

The H atom bonded to a N atom was located in a difference map and was refined freely. Other H atoms were placed in calculated positions, with C—H = 0.95–1.00 Å, and included in the final cycles of refinement using a riding model, with U_iso(H) = 1.2–1.5U_eq(parent atom).

Computing details

Data collection: CrystalClear (Rigaku/MSC, 2002); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1999); software used to prepare material for publication: SHELXL97.

Figures

	Fig. 1. The molecular structure of the title compound, showing 30% probability displacement ellipsoids and the atom-numbering scheme.
	Fig. 2. The packing diagram of the title compound. Intermolecular hydrogen bonds are shown as dashed lines.

Methyl 7-(4-bromophenyl)-5-methyl-4,7-dihydrotetrazolo[1,5-a]pyrimidine- 6-carboxylate

Crystal data

C13H12BrN5O2	F(000) = 704
Mr = 350.19	Dx = 1.701 Mg m^−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71070 Å
Hall symbol: -P 2ybc	Cell parameters from 3874 reflections
a = 17.907 (2) Å	θ = 2.3–27.9°
b = 10.1825 (12) Å	µ = 3.02 mm^−1
c = 7.5055 (8) Å	T = 113 K
β = 92.166 (6)°	Prism, colourless
V = 1367.6 (3) Å^3	0.16 × 0.14 × 0.10 mm
Z = 4

Data collection

Rigaku Saturn diffractometer	3261 independent reflections
Radiation source: rotating anode	2480 reflections with I > 2σ(I)
Confocal monochromator	Rint = 0.054
Detector resolution: 7.31 pixels mm^-1	θmax = 27.9°, θmin = 2.3°
ω scans	h = −23→22
Absorption correction: multi-scan (CrystalClear; Rigaku/MSC, 2002)	k = −13→11
Tmin = 0.644, Tmax = 0.752	l = −9→8
10315 measured reflections

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)] = 0.035	Hydrogen site location: inferred from neighbouring sites
wR(F^2) = 0.083	H atoms treated by a mixture of independent and constrained refinement
S = 0.99	w = 1/[σ^2(Fo^2) + (0.0433P)^2] where P = (Fo^2 + 2Fc^2)/3
3261 reflections	(Δ/σ)max = 0.001
196 parameters	Δρmax = 0.98 e Å^−3
0 restraints	Δρmin = −1.14 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	0.004726 (12)	0.27862 (2)	0.46614 (4)	0.02132 (10)
O1	0.29676 (9)	0.06840 (16)	−0.1887 (2)	0.0220 (4)
O2	0.21121 (9)	−0.05636 (16)	−0.0569 (2)	0.0180 (4)
N1	0.32618 (9)	−0.09411 (17)	0.4092 (3)	0.0127 (4)
N2	0.31537 (10)	−0.17956 (19)	0.5438 (3)	0.0176 (4)
N3	0.37654 (10)	−0.1804 (2)	0.6404 (3)	0.0202 (5)
N4	0.42826 (10)	−0.09703 (19)	0.5731 (3)	0.0175 (4)
N5	0.42234 (11)	0.0382 (2)	0.3083 (3)	0.0184 (4)
C1	0.27228 (12)	−0.0655 (2)	0.2624 (3)	0.0132 (5)
H1	0.2521	−0.1504	0.2140	0.016*
C2	0.39545 (12)	−0.0462 (2)	0.4286 (3)	0.0146 (5)
C3	0.38423 (13)	0.0551 (2)	0.1451 (3)	0.0153 (5)
C4	0.31497 (12)	0.0029 (2)	0.1174 (3)	0.0141 (5)
C5	0.20761 (12)	0.0163 (2)	0.3260 (3)	0.0131 (5)
C6	0.13503 (13)	−0.0321 (2)	0.3065 (3)	0.0153 (5)
H6	0.1270	−0.1185	0.2622	0.018*
C7	0.07433 (12)	0.0442 (2)	0.3509 (3)	0.0172 (5)
H7	0.0248	0.0115	0.3353	0.021*
C8	0.08719 (12)	0.1684 (2)	0.4182 (3)	0.0157 (5)
C9	0.15873 (12)	0.2177 (2)	0.4453 (4)	0.0172 (5)
H9	0.1665	0.3025	0.4954	0.021*
C10	0.21876 (12)	0.1413 (2)	0.3980 (3)	0.0158 (5)
H10	0.2681	0.1743	0.4149	0.019*
C11	0.42716 (13)	0.1333 (3)	0.0139 (4)	0.0245 (6)
H11A	0.4271	0.0866	−0.1003	0.037*
H11B	0.4787	0.1448	0.0596	0.037*
H11C	0.4037	0.2195	−0.0033	0.037*
C12	0.27653 (13)	0.0108 (2)	−0.0590 (3)	0.0155 (5)
C13	0.16691 (13)	−0.0577 (3)	−0.2211 (3)	0.0209 (5)
H13A	0.1594	0.0326	−0.2635	0.031*
H13B	0.1183	−0.0981	−0.2007	0.031*
H13C	0.1929	−0.1084	−0.3109	0.031*
H5	0.4699 (16)	0.065 (3)	0.325 (4)	0.030 (8)*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.01894 (14)	0.02864 (16)	0.01634 (16)	0.00961 (10)	0.00019 (10)	−0.00313 (10)
O1	0.0226 (9)	0.0263 (9)	0.0171 (10)	−0.0007 (7)	0.0014 (8)	0.0043 (8)
O2	0.0168 (8)	0.0252 (9)	0.0118 (9)	−0.0009 (7)	−0.0027 (7)	0.0017 (7)
N1	0.0120 (8)	0.0137 (9)	0.0125 (11)	−0.0016 (7)	0.0012 (8)	0.0022 (8)
N2	0.0165 (9)	0.0195 (10)	0.0168 (12)	−0.0015 (8)	−0.0003 (9)	0.0051 (9)
N3	0.0151 (9)	0.0243 (10)	0.0210 (12)	−0.0021 (8)	−0.0022 (9)	0.0065 (9)
N4	0.0141 (9)	0.0211 (10)	0.0172 (11)	−0.0009 (8)	−0.0003 (8)	0.0057 (9)
N5	0.0127 (9)	0.0230 (10)	0.0194 (12)	−0.0057 (8)	−0.0019 (9)	0.0059 (9)
C1	0.0112 (10)	0.0140 (11)	0.0143 (12)	−0.0009 (8)	−0.0017 (9)	0.0012 (9)
C2	0.0114 (10)	0.0147 (10)	0.0179 (13)	−0.0009 (8)	0.0011 (9)	0.0004 (10)
C3	0.0162 (10)	0.0148 (11)	0.0151 (13)	0.0017 (9)	0.0027 (10)	0.0012 (9)
C4	0.0153 (10)	0.0139 (11)	0.0133 (13)	0.0032 (8)	0.0021 (10)	0.0015 (9)
C5	0.0133 (10)	0.0171 (11)	0.0090 (12)	0.0002 (8)	0.0003 (9)	0.0015 (9)
C6	0.0150 (10)	0.0159 (11)	0.0148 (13)	−0.0025 (9)	−0.0009 (10)	−0.0019 (10)
C7	0.0127 (10)	0.0239 (12)	0.0149 (13)	−0.0032 (9)	−0.0016 (10)	0.0018 (10)
C8	0.0151 (10)	0.0192 (11)	0.0129 (12)	0.0054 (9)	0.0015 (9)	0.0027 (10)
C9	0.0194 (11)	0.0143 (11)	0.0178 (14)	−0.0016 (9)	−0.0001 (10)	0.0000 (10)
C10	0.0136 (10)	0.0168 (11)	0.0168 (13)	−0.0014 (9)	−0.0015 (10)	0.0009 (9)
C11	0.0181 (11)	0.0326 (14)	0.0230 (15)	−0.0031 (10)	0.0026 (11)	0.0111 (12)
C12	0.0152 (10)	0.0152 (11)	0.0162 (13)	0.0031 (9)	0.0033 (10)	−0.0012 (9)
C13	0.0184 (11)	0.0304 (13)	0.0137 (13)	0.0011 (10)	−0.0041 (10)	0.0002 (11)

Geometric parameters (Å, º)

Br1—C8	1.900 (2)	C4—C12	1.471 (3)
O1—C12	1.204 (3)	C5—C6	1.393 (3)
O2—C12	1.356 (3)	C5—C10	1.394 (3)
O2—C13	1.441 (3)	C6—C7	1.387 (3)
N1—C2	1.336 (3)	C6—H6	0.95
N1—N2	1.353 (3)	C7—C8	1.377 (3)
N1—C1	1.466 (3)	C7—H7	0.95
N2—N3	1.291 (3)	C8—C9	1.384 (3)
N3—N4	1.367 (3)	C9—C10	1.384 (3)
N4—C2	1.320 (3)	C9—H9	0.95
N5—C2	1.348 (3)	C10—H10	0.95
N5—C3	1.390 (3)	C11—H11A	0.98
N5—H5	0.90 (3)	C11—H11B	0.98
C1—C5	1.518 (3)	C11—H11C	0.98
C1—C4	1.522 (3)	C13—H13A	0.98
C1—H1	1.00	C13—H13B	0.98
C3—C4	1.358 (3)	C13—H13C	0.98
C3—C11	1.500 (3)
C12—O2—C13	116.22 (19)	C7—C6—H6	119.6
C2—N1—N2	108.20 (18)	C5—C6—H6	119.6
C2—N1—C1	126.2 (2)	C8—C7—C6	118.7 (2)
N2—N1—C1	125.47 (17)	C8—C7—H7	120.6
N3—N2—N1	106.34 (18)	C6—C7—H7	120.6
N2—N3—N4	111.16 (19)	C7—C8—C9	121.9 (2)
C2—N4—N3	105.10 (17)	C7—C8—Br1	119.42 (16)
C2—N5—C3	119.55 (19)	C9—C8—Br1	118.66 (17)
C2—N5—H5	117.4 (18)	C8—C9—C10	118.8 (2)
C3—N5—H5	121.2 (19)	C8—C9—H9	120.6
N1—C1—C5	111.18 (19)	C10—C9—H9	120.6
N1—C1—C4	107.10 (17)	C9—C10—C5	120.8 (2)
C5—C1—C4	112.55 (18)	C9—C10—H10	119.6
N1—C1—H1	108.6	C5—C10—H10	119.6
C5—C1—H1	108.6	C3—C11—H11A	109.5
C4—C1—H1	108.6	C3—C11—H11B	109.5
N4—C2—N1	109.2 (2)	H11A—C11—H11B	109.5
N4—C2—N5	129.9 (2)	C3—C11—H11C	109.5
N1—C2—N5	120.9 (2)	H11A—C11—H11C	109.5
C4—C3—N5	120.1 (2)	H11B—C11—H11C	109.5
C4—C3—C11	126.5 (2)	O1—C12—O2	122.8 (2)
N5—C3—C11	113.41 (19)	O1—C12—C4	127.5 (2)
C3—C4—C12	120.6 (2)	O2—C12—C4	109.6 (2)
C3—C4—C1	123.4 (2)	O2—C13—H13A	109.5
C12—C4—C1	115.98 (19)	O2—C13—H13B	109.5
C6—C5—C10	118.9 (2)	H13A—C13—H13B	109.5
C6—C5—C1	119.54 (19)	O2—C13—H13C	109.5
C10—C5—C1	121.53 (19)	H13A—C13—H13C	109.5
C7—C6—C5	120.9 (2)	H13B—C13—H13C	109.5
C2—N1—N2—N3	0.7 (3)	C5—C1—C4—C3	107.3 (2)
C1—N1—N2—N3	177.5 (2)	N1—C1—C4—C12	165.17 (18)
N1—N2—N3—N4	0.0 (3)	C5—C1—C4—C12	−72.3 (2)
N2—N3—N4—C2	−0.6 (3)	N1—C1—C5—C6	−120.8 (2)
C2—N1—C1—C5	−110.9 (3)	C4—C1—C5—C6	119.0 (2)
N2—N1—C1—C5	72.9 (3)	N1—C1—C5—C10	61.5 (3)
C2—N1—C1—C4	12.4 (3)	C4—C1—C5—C10	−58.7 (3)
N2—N1—C1—C4	−163.8 (2)	C10—C5—C6—C7	2.6 (4)
N3—N4—C2—N1	1.1 (3)	C1—C5—C6—C7	−175.2 (2)
N3—N4—C2—N5	−177.4 (3)	C5—C6—C7—C8	−1.2 (4)
N2—N1—C2—N4	−1.1 (3)	C6—C7—C8—C9	−1.2 (4)
C1—N1—C2—N4	−177.9 (2)	C6—C7—C8—Br1	176.14 (18)
N2—N1—C2—N5	177.5 (2)	C7—C8—C9—C10	2.1 (4)
C1—N1—C2—N5	0.7 (4)	Br1—C8—C9—C10	−175.25 (19)
C3—N5—C2—N4	165.1 (2)	C8—C9—C10—C5	−0.6 (4)
C3—N5—C2—N1	−13.2 (4)	C6—C5—C10—C9	−1.7 (4)
C2—N5—C3—C4	10.0 (4)	C1—C5—C10—C9	176.1 (2)
C2—N5—C3—C11	−170.0 (2)	C13—O2—C12—O1	1.1 (3)
N5—C3—C4—C12	−175.0 (2)	C13—O2—C12—C4	−179.99 (18)
C11—C3—C4—C12	5.0 (4)	C3—C4—C12—O1	−5.7 (4)
N5—C3—C4—C1	5.4 (4)	C1—C4—C12—O1	173.9 (2)
C11—C3—C4—C1	−174.6 (2)	C3—C4—C12—O2	175.5 (2)
N1—C1—C4—C3	−15.2 (3)	C1—C4—C12—O2	−4.9 (3)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N5—H5···N4^i	0.90 (3)	1.98 (3)	2.851 (3)	164 (3)

Symmetry code: (i) −x+1, −y, −z+1.