Methyl 5-(4-hy-droxy-3-meth-oxy-phen-yl)-2-(4-meth-oxy-benzyl-idene)-7-methyl-3-oxo-2,3-dihydro-5H-thia-zolo[3,2-a]pyrimidine-6-carboxyl-ate.

In the title compound, C(24)H(22)N(2)O(6)S, a pyrimidine ring substituted with 4-hy-droxy-3-meth-oxy-phenyl is fused with a thia-zole ring. The 4-hy-droxy-3-meth-oxy-phenyl group is positioned axially to the pyrimidine ring, making a dihedral angle 85.36 (7)°. The pyrimidine ring adopts a twist boat conformation. In the crystal, O-H⋯N inter-actions result in a chain running along the b axis. The carbonyl O atom bonded to the thia-zole ring is involved in two C-H⋯O hydrogen-bond inter-actions forming centrosymmetric dimers; the ten- and six-membered rings resulting from these inter-actions have R(2) (2)(10) and R(1) (2)(6) motifs, respectively.

Related literature

For pharmacological properties of pyrimidine derivatives, see: Alam et al. (2010 ▶). For related structures, see: Jotani et al. (2010 ▶). For graph-set motifs, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C24H22N2O6S

M = 466.50

Triclinic,

a = 6.8096 (12) Å

b = 9.9343 (18) Å

c = 16.246 (3) Å

α = 86.816 (3)°

β = 85.588 (3)°

γ = 81.318 (3)°

V = 1082.1 (3) Å3

Z = 2

Mo Kα radiation

μ = 0.20 mm−1

T = 296 K

0.18 × 0.16 × 0.16 mm

Data collection

Bruker SMART APEX CCD detector diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 1998 ▶) T min = 0.966, T max = 0.969

6570 measured reflections

4581 independent reflections

3452 reflections with I > 2σ(I)

R int = 0.018

Refinement

R[F 2 > 2σ(F 2)] = 0.069

wR(F 2) = 0.279

S = 1.33

4581 reflections

303 parameters

H-atom parameters constrained

Δρmax = 0.69 e Å−3

Δρmin = −0.62 e Å−3

Data collection: SMART (Bruker, 1998 ▶); cell refinement: SAINT-Plus (Bruker, 1998 ▶); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and CAMERON (Watkin et al., 1996 ▶); software used to prepare material for publication: WinGX (Farrugia, 1999 ▶).

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811048987/pv2473sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811048987/pv2473Isup2.hkl

Supplementary material file. DOI: 10.1107/S1600536811048987/pv2473Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C24H22N2O6S	V = 1082.1 (3) Å3
Mr = 466.50	Z = 2
Triclinic, P1	F(000) = 488
Hall symbol: -P 1	Dx = 1.432 Mg m−3
a = 6.8096 (12) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.9343 (18) Å	µ = 0.20 mm−1
c = 16.246 (3) Å	T = 296 K
α = 86.816 (3)°	Block, yellow
β = 85.588 (3)°	0.18 × 0.16 × 0.16 mm
γ = 81.318 (3)°

Bruker SMART APEX CCD detector diffractometer	4581 independent reflections
Radiation source: fine-focus sealed tube	3452 reflections with I > 2σ(I)
graphite	Rint = 0.018
ω scans	θmax = 27.0°, θmin = 2.1°
Absorption correction: multi-scan (SADABS; Bruker, 1998)	h = −8→8
Tmin = 0.966, Tmax = 0.969	k = −12→10
6570 measured reflections	l = −20→20

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.069	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.279	H-atom parameters constrained
S = 1.33	w = 1/[σ2(Fo2) + (0.1558P)2] where P = (Fo2 + 2Fc2)/3
4581 reflections	(Δ/σ)max < 0.001
303 parameters	Δρmax = 0.69 e Å−3
0 restraints	Δρmin = −0.62 e Å−3

Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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.

	x	y	z	Uiso*/Ueq
S1	0.15410 (13)	0.32220 (9)	0.29148 (5)	0.0312 (3)
O6	0.0905 (4)	−0.4233 (2)	0.13814 (16)	0.0352 (6)
H6	0.0110	−0.4779	0.1447	0.053*
O2	−0.1068 (4)	0.0292 (2)	0.39078 (14)	0.0314 (6)
N1	−0.1155 (4)	0.1703 (3)	0.27435 (16)	0.0257 (6)
O3	−0.6100 (4)	0.0792 (3)	0.16436 (16)	0.0372 (6)
N2	−0.0791 (5)	0.3389 (3)	0.16660 (17)	0.0299 (7)
O1	0.8821 (4)	0.3698 (3)	0.54235 (17)	0.0415 (7)
C6	−0.3314 (5)	0.1959 (3)	0.15964 (19)	0.0263 (7)
O5	−0.2673 (4)	−0.3960 (2)	0.22167 (17)	0.0365 (6)
C5	−0.2615 (5)	0.1047 (3)	0.2339 (2)	0.0276 (7)
H5	−0.3765	0.0977	0.2733	0.033*
C19	−0.2694 (5)	−0.1507 (3)	0.2295 (2)	0.0276 (7)
H19	−0.3925	−0.1391	0.2593	0.033*
O4	−0.5284 (4)	0.1916 (3)	0.04588 (15)	0.0465 (8)
C21	0.0002 (5)	−0.2994 (3)	0.1616 (2)	0.0288 (7)
C18	−0.1708 (5)	−0.0377 (3)	0.20939 (19)	0.0264 (7)
C3	−0.0444 (5)	0.1214 (3)	0.3500 (2)	0.0281 (7)
C12	0.4787 (5)	0.1626 (4)	0.5346 (2)	0.0298 (7)
H12	0.4232	0.0936	0.5647	0.036*
C8	−0.0300 (5)	0.2758 (3)	0.2354 (2)	0.0281 (7)
C20	−0.1849 (5)	−0.2791 (3)	0.20538 (19)	0.0271 (7)
C22	0.0966 (5)	−0.1868 (3)	0.1404 (2)	0.0313 (8)
H22	0.2194	−0.1982	0.1103	0.038*
C2	0.1203 (5)	0.1940 (3)	0.3687 (2)	0.0297 (7)
C10	0.2243 (5)	0.1629 (3)	0.4359 (2)	0.0276 (7)
H10	0.1809	0.0946	0.4709	0.033*
C11	0.3928 (5)	0.2179 (4)	0.4631 (2)	0.0315 (8)
C7	−0.2434 (5)	0.3037 (3)	0.1307 (2)	0.0284 (7)
C14	0.7248 (5)	0.3131 (4)	0.5199 (2)	0.0321 (8)
C23	0.0097 (5)	−0.0576 (4)	0.1639 (2)	0.0324 (8)
H23	0.0747	0.0168	0.1487	0.039*
C13	0.6444 (5)	0.2068 (4)	0.5625 (2)	0.0335 (8)
H13	0.7015	0.1654	0.6095	0.040*
C1	−0.3048 (6)	0.4018 (4)	0.0603 (2)	0.0382 (9)
H1A	−0.2234	0.3761	0.0112	0.057*
H1B	−0.2881	0.4922	0.0735	0.057*
H1C	−0.4419	0.3997	0.0514	0.057*
C4	−0.5039 (5)	0.1509 (4)	0.1248 (2)	0.0321 (8)
C15	0.6422 (6)	0.3702 (4)	0.4484 (2)	0.0405 (9)
H15	0.6966	0.4408	0.4194	0.049*
C17	0.9714 (6)	0.3169 (4)	0.6163 (2)	0.0397 (9)
H17A	0.8779	0.3364	0.6630	0.060*
H17B	1.0875	0.3587	0.6223	0.060*
H17C	1.0090	0.2201	0.6135	0.060*
C16	0.4802 (6)	0.3238 (4)	0.4194 (2)	0.0375 (9)
H16	0.4281	0.3623	0.3708	0.045*
C24	−0.4702 (6)	−0.3847 (4)	0.2508 (3)	0.0441 (10)
H24A	−0.4846	−0.3583	0.3071	0.066*
H24B	−0.5158	−0.4710	0.2476	0.066*
H24C	−0.5479	−0.3171	0.2173	0.066*
C9	−0.7019 (7)	0.1526 (6)	0.0106 (3)	0.0592 (14)
H9A	−0.7048	0.0570	0.0218	0.089*
H9B	−0.6936	0.1714	−0.0480	0.089*
H9C	−0.8212	0.2037	0.0349	0.089*

	U11	U22	U33	U12	U13	U23
S1	0.0364 (5)	0.0289 (5)	0.0312 (5)	−0.0120 (4)	−0.0098 (4)	0.0032 (3)
O6	0.0355 (14)	0.0286 (13)	0.0421 (15)	−0.0088 (10)	0.0013 (11)	−0.0022 (11)
O2	0.0380 (14)	0.0306 (13)	0.0281 (12)	−0.0132 (11)	−0.0077 (10)	0.0057 (10)
N1	0.0267 (15)	0.0245 (14)	0.0270 (14)	−0.0077 (11)	−0.0056 (11)	0.0039 (11)
O3	0.0300 (14)	0.0459 (16)	0.0385 (14)	−0.0149 (12)	−0.0089 (11)	0.0070 (12)
N2	0.0384 (17)	0.0251 (15)	0.0287 (15)	−0.0107 (12)	−0.0077 (12)	0.0000 (11)
O1	0.0365 (15)	0.0447 (16)	0.0481 (16)	−0.0150 (12)	−0.0171 (12)	−0.0011 (13)
C6	0.0282 (17)	0.0274 (17)	0.0242 (16)	−0.0065 (13)	−0.0064 (13)	0.0047 (13)
O5	0.0351 (14)	0.0282 (13)	0.0480 (15)	−0.0142 (11)	0.0049 (11)	−0.0023 (11)
C5	0.0259 (17)	0.0287 (17)	0.0308 (17)	−0.0114 (13)	−0.0068 (13)	0.0036 (13)
C19	0.0250 (17)	0.0305 (18)	0.0296 (17)	−0.0111 (13)	−0.0034 (13)	0.0005 (13)
O4	0.0453 (17)	0.070 (2)	0.0309 (14)	−0.0285 (15)	−0.0194 (12)	0.0146 (13)
C21	0.0297 (18)	0.0279 (17)	0.0298 (17)	−0.0072 (13)	−0.0065 (13)	0.0030 (13)
C18	0.0270 (17)	0.0288 (17)	0.0250 (16)	−0.0072 (13)	−0.0089 (12)	0.0029 (13)
C3	0.0309 (18)	0.0264 (17)	0.0276 (17)	−0.0049 (14)	−0.0067 (13)	0.0002 (13)
C12	0.0302 (18)	0.0326 (18)	0.0280 (17)	−0.0071 (14)	−0.0057 (13)	−0.0014 (14)
C8	0.0279 (18)	0.0255 (16)	0.0308 (17)	−0.0032 (13)	−0.0015 (13)	−0.0030 (13)
C20	0.0340 (19)	0.0248 (17)	0.0253 (16)	−0.0122 (14)	−0.0055 (13)	0.0009 (13)
C22	0.0272 (18)	0.0269 (18)	0.0398 (19)	−0.0058 (13)	−0.0019 (14)	0.0028 (14)
C2	0.0319 (19)	0.0269 (17)	0.0324 (17)	−0.0098 (14)	−0.0022 (14)	−0.0064 (14)
C10	0.0296 (18)	0.0292 (18)	0.0258 (16)	−0.0086 (14)	−0.0056 (13)	−0.0011 (13)
C11	0.0317 (19)	0.0308 (18)	0.0329 (18)	−0.0074 (14)	−0.0018 (14)	−0.0001 (14)
C7	0.0281 (18)	0.0276 (17)	0.0303 (17)	−0.0035 (13)	−0.0096 (13)	0.0007 (13)
C14	0.0293 (19)	0.0285 (18)	0.0396 (19)	−0.0040 (14)	−0.0073 (14)	−0.0034 (15)
C23	0.0272 (18)	0.0298 (18)	0.043 (2)	−0.0118 (14)	−0.0066 (14)	0.0030 (15)
C13	0.0300 (19)	0.0342 (19)	0.0354 (19)	0.0006 (14)	−0.0067 (14)	−0.0023 (15)
C1	0.047 (2)	0.0300 (19)	0.039 (2)	−0.0091 (16)	−0.0150 (17)	0.0093 (16)
C4	0.0279 (18)	0.0346 (19)	0.0338 (18)	−0.0040 (14)	−0.0063 (14)	0.0029 (15)
C15	0.040 (2)	0.039 (2)	0.046 (2)	−0.0174 (17)	−0.0140 (17)	0.0082 (17)
C17	0.034 (2)	0.049 (2)	0.039 (2)	−0.0080 (17)	−0.0112 (16)	−0.0030 (17)
C16	0.044 (2)	0.0294 (19)	0.041 (2)	−0.0110 (16)	−0.0120 (17)	0.0061 (15)
C24	0.035 (2)	0.034 (2)	0.063 (3)	−0.0134 (16)	0.0078 (18)	−0.0012 (18)
C9	0.048 (3)	0.095 (4)	0.042 (2)	−0.032 (3)	−0.021 (2)	0.017 (2)

S1—C8	1.735 (3)	C12—C13	1.387 (5)
S1—C2	1.765 (4)	C12—C11	1.388 (5)
O6—C21	1.352 (4)	C12—H12	0.9300
O6—H6	0.8200	C22—C23	1.391 (5)
O2—C3	1.210 (4)	C22—H22	0.9300
N1—C8	1.376 (4)	C2—C10	1.343 (5)
N1—C3	1.391 (4)	C10—C11	1.451 (4)
N1—C5	1.479 (4)	C10—H10	0.9300
O3—C4	1.215 (4)	C11—C16	1.416 (5)
N2—C8	1.292 (4)	C7—C1	1.503 (5)
N2—C7	1.398 (4)	C14—C15	1.386 (5)
O1—C14	1.364 (4)	C14—C13	1.389 (5)
O1—C17	1.427 (4)	C23—H23	0.9300
C6—C7	1.350 (5)	C13—H13	0.9300
C6—C4	1.479 (5)	C1—H1A	0.9600
C6—C5	1.530 (4)	C1—H1B	0.9600
O5—C20	1.369 (4)	C1—H1C	0.9600
O5—C24	1.416 (4)	C15—C16	1.382 (5)
C5—C18	1.518 (5)	C15—H15	0.9300
C5—H5	0.9800	C17—H17A	0.9600
C19—C20	1.382 (5)	C17—H17B	0.9600
C19—C18	1.404 (4)	C17—H17C	0.9600
C19—H19	0.9300	C16—H16	0.9300
O4—C4	1.338 (4)	C24—H24A	0.9600
O4—C9	1.463 (4)	C24—H24B	0.9600
C21—C20	1.392 (5)	C24—H24C	0.9600
C21—C22	1.395 (4)	C9—H9A	0.9600
C18—C23	1.378 (5)	C9—H9B	0.9600
C3—C2	1.480 (4)	C9—H9C	0.9600
C8—S1—C2	91.56 (16)	C12—C11—C16	117.3 (3)
C21—O6—H6	109.5	C12—C11—C10	119.2 (3)
C8—N1—C3	116.4 (3)	C16—C11—C10	123.6 (3)
C8—N1—C5	121.3 (3)	C6—C7—N2	121.8 (3)
C3—N1—C5	122.1 (3)	C6—C7—C1	127.0 (3)
C8—N2—C7	117.4 (3)	N2—C7—C1	111.2 (3)
C14—O1—C17	117.6 (3)	O1—C14—C15	115.0 (3)
C7—C6—C4	125.2 (3)	O1—C14—C13	125.7 (3)
C7—C6—C5	122.9 (3)	C15—C14—C13	119.3 (3)
C4—C6—C5	111.8 (3)	C18—C23—C22	121.2 (3)
C20—O5—C24	118.5 (3)	C18—C23—H23	119.4
N1—C5—C18	110.5 (3)	C22—C23—H23	119.4
N1—C5—C6	108.4 (2)	C12—C13—C14	119.7 (3)
C18—C5—C6	112.2 (3)	C12—C13—H13	120.2
N1—C5—H5	108.6	C14—C13—H13	120.2
C18—C5—H5	108.6	C7—C1—H1A	109.5
C6—C5—H5	108.6	C7—C1—H1B	109.5
C20—C19—C18	120.5 (3)	H1A—C1—H1B	109.5
C20—C19—H19	119.8	C7—C1—H1C	109.5
C18—C19—H19	119.8	H1A—C1—H1C	109.5
C4—O4—C9	115.8 (3)	H1B—C1—H1C	109.5
O6—C21—C20	123.0 (3)	O3—C4—O4	123.1 (3)
O6—C21—C22	118.4 (3)	O3—C4—C6	122.2 (3)
C20—C21—C22	118.6 (3)	O4—C4—C6	114.6 (3)
C23—C18—C19	118.5 (3)	C16—C15—C14	121.0 (3)
C23—C18—C5	119.9 (3)	C16—C15—H15	119.5
C19—C18—C5	121.6 (3)	C14—C15—H15	119.5
O2—C3—N1	123.1 (3)	O1—C17—H17A	109.5
O2—C3—C2	127.1 (3)	O1—C17—H17B	109.5
N1—C3—C2	109.7 (3)	H17A—C17—H17B	109.5
C13—C12—C11	122.2 (3)	O1—C17—H17C	109.5
C13—C12—H12	118.9	H17A—C17—H17C	109.5
C11—C12—H12	118.9	H17B—C17—H17C	109.5
N2—C8—N1	126.2 (3)	C15—C16—C11	120.5 (3)
N2—C8—S1	121.8 (3)	C15—C16—H16	119.7
N1—C8—S1	112.0 (2)	C11—C16—H16	119.7
O5—C20—C19	125.4 (3)	O5—C24—H24A	109.5
O5—C20—C21	113.7 (3)	O5—C24—H24B	109.5
C19—C20—C21	120.9 (3)	H24A—C24—H24B	109.5
C23—C22—C21	120.2 (3)	O5—C24—H24C	109.5
C23—C22—H22	119.9	H24A—C24—H24C	109.5
C21—C22—H22	119.9	H24B—C24—H24C	109.5
C10—C2—C3	122.8 (3)	O4—C9—H9A	109.5
C10—C2—S1	126.9 (3)	O4—C9—H9B	109.5
C3—C2—S1	110.3 (2)	H9A—C9—H9B	109.5
C2—C10—C11	131.0 (3)	O4—C9—H9C	109.5
C2—C10—H10	114.5	H9A—C9—H9C	109.5
C11—C10—H10	114.5	H9B—C9—H9C	109.5
C8—N1—C5—C18	108.8 (3)	N1—C3—C2—C10	−176.5 (3)
C3—N1—C5—C18	−65.4 (4)	O2—C3—C2—S1	−179.2 (3)
C8—N1—C5—C6	−14.4 (4)	N1—C3—C2—S1	3.7 (4)
C3—N1—C5—C6	171.3 (3)	C8—S1—C2—C10	177.4 (3)
C7—C6—C5—N1	10.4 (5)	C8—S1—C2—C3	−2.8 (3)
C4—C6—C5—N1	−169.6 (3)	C3—C2—C10—C11	177.5 (3)
C7—C6—C5—C18	−111.9 (4)	S1—C2—C10—C11	−2.7 (6)
C4—C6—C5—C18	68.1 (4)	C13—C12—C11—C16	−0.6 (6)
C20—C19—C18—C23	1.1 (5)	C13—C12—C11—C10	177.6 (3)
C20—C19—C18—C5	179.0 (3)	C2—C10—C11—C12	−177.3 (4)
N1—C5—C18—C23	−51.6 (4)	C2—C10—C11—C16	0.8 (6)
C6—C5—C18—C23	69.4 (4)	C4—C6—C7—N2	−179.3 (3)
N1—C5—C18—C19	130.5 (3)	C5—C6—C7—N2	0.7 (5)
C6—C5—C18—C19	−108.4 (3)	C4—C6—C7—C1	2.2 (6)
C8—N1—C3—O2	179.9 (3)	C5—C6—C7—C1	−177.8 (3)
C5—N1—C3—O2	−5.6 (5)	C8—N2—C7—C6	−9.0 (5)
C8—N1—C3—C2	−2.9 (4)	C8—N2—C7—C1	169.7 (3)
C5—N1—C3—C2	171.6 (3)	C17—O1—C14—C15	179.0 (3)
C7—N2—C8—N1	4.7 (5)	C17—O1—C14—C13	−0.7 (5)
C7—N2—C8—S1	−173.2 (2)	C19—C18—C23—C22	−2.0 (5)
C3—N1—C8—N2	−177.3 (3)	C5—C18—C23—C22	−179.9 (3)
C5—N1—C8—N2	8.1 (5)	C21—C22—C23—C18	0.9 (5)
C3—N1—C8—S1	0.8 (4)	C11—C12—C13—C14	2.3 (6)
C5—N1—C8—S1	−173.7 (2)	O1—C14—C13—C12	177.3 (3)
C2—S1—C8—N2	179.4 (3)	C15—C14—C13—C12	−2.3 (6)
C2—S1—C8—N1	1.2 (3)	C9—O4—C4—O3	4.3 (6)
C24—O5—C20—C19	13.4 (5)	C9—O4—C4—C6	−178.0 (4)
C24—O5—C20—C21	−167.5 (3)	C7—C6—C4—O3	−159.7 (4)
C18—C19—C20—O5	179.9 (3)	C5—C6—C4—O3	20.3 (5)
C18—C19—C20—C21	0.8 (5)	C7—C6—C4—O4	22.6 (5)
O6—C21—C20—O5	−0.6 (5)	C5—C6—C4—O4	−157.4 (3)
C22—C21—C20—O5	178.9 (3)	O1—C14—C15—C16	−179.0 (4)
O6—C21—C20—C19	178.6 (3)	C13—C14—C15—C16	0.6 (6)
C22—C21—C20—C19	−1.9 (5)	C14—C15—C16—C11	1.1 (6)
O6—C21—C22—C23	−179.4 (3)	C12—C11—C16—C15	−1.0 (6)
C20—C21—C22—C23	1.0 (5)	C10—C11—C16—C15	−179.2 (4)
O2—C3—C2—C10	0.6 (6)

D—H···A	D—H	H···A	D···A	D—H···A
O6—H6···N2i	0.82	2.01	2.783 (4)	156
C10—H10···O2ii	0.93	2.55	3.425 (4)	156
C12—H12···O2ii	0.93	2.67	3.499 (4)	149
C1—H1A···O6iii	0.96	2.57	3.444 (5)	152
C17—H17C···O2iv	0.96	2.47	3.429 (5)	179

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O6—H6⋯N2i	0.82	2.01	2.783 (4)	156
C10—H10⋯O2ii	0.93	2.55	3.425 (4)	156
C12—H12⋯O2ii	0.93	2.67	3.499 (4)	149
C1—H1A⋯O6iii	0.96	2.57	3.444 (5)	152
C17—H17C⋯O2iv	0.96	2.47	3.429 (5)	179

Symmetry codes: (i) ; (ii) ; (iii) ; (iv) .