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355
in a dry 5 mm sample tube (New Era Enterprises NE-HP5-9”)
then the solution was subjected to five freeze–pump–thraw
cycles before being sealed under nitrogen. Chemical shifts
δ are given in parts per million (ppm) relative to T.S.P. ((3-
trimethylsilyl)-propionic acid-d4 sodium salt) obtained from
Merck (Art. 8652) used as internal standard and the coupling
constants in Hz. NOESY studies were acquired in the phase-
sensitive mode, using the noesytp program with a mixing
time set to 400 ms and 32 scans per time increment.
The double-quantum filtered GDQF-COSY experiment
was acquired in the phase-sensitive mode using time-
proportional phase increment (TPPI) with a spectral width of
903.18 Hz in both dimensions (cosygpmftp program), 1 × 2K
data points before and 2K × 2K after zero-filling, resulting in
a digital resolution of 0.44 Hz per point in the ω1 and ω2 di-
mensions. Processing was carried out using sine-bell squared
functions shifted by π/2.
and isotropic thermal displacement were refined. Electron
density residuals in the final Fourier difference map were
+0.49 and −0.28 e A−3. The ellipsoid plot was drawn using
˚
ORTEP-3 for windows [11] which is a MS-windows version
of the current release of ORTEP-III. All computations were
carried out on a Pentium 4 computer.
The powder diffraction measurements were undertaken
equipped with a copper tube, a hybrid monochromator (a
parabolic multilayer mirror and a two-crystal monochroma-
tor) and the Xcelerator detector. Rietveld analyses were per-
formed using the program LHPM-Rietica [12].
2.4. Differential scanning calorimetry
Differential scanning calorimetry was performed with a
DSC Q100 (TA Instrument) equipped with Universal Anal-
ysis 2000 software. The calibration (temperature and cell
constant) was done using an indium standard (SPIN, ref.
LGC2601). Assays were performed at rate of 5 ◦C min−1
from 0 to 170 ◦C in hermetic aluminium pans (TA instru-
ments, pan: 900793.901, lid: 900794.901) under nitrogen
purge at 50 mL min−1. Samples, about 5 mg, were weighed
with a Sartorius ultramicrobalance MP 8.
19F NMR spectra were recorded on the title compound
at 188.2 MHz on a Bruker AC200 spectrometer, at ambient
temperature, in methyl alcohol-d4 (Euriso-top, D324 B, batch
IO491) solution. Proton-decoupled and proton-coupled spec-
tra were recorded. Chemical shifts δ are given in parts per
million (ppm) relative to trifluoro-acetic acid in benzene-d6.
2.3. X-ray diffraction
2.5. Thermogravimetry analysis
The crystallized compound was obtained as follows:
1 g of 1 was dissolved in warm isopropanol (40 mL) and
allowed to stand, in an open flask, at room temperature for
8 days. The resulting crystals were filtered and dried under
reduced pressure. Enraf-Nonius CAD-4 diffractometer was
used for X-ray diffraction data collection at T = 293 K using
TGA and DTG curves were obtained using a TA High
Resolution 2950 thermogravimeter analyzer equipped with
the Universal Analysis 2000 software (TA Instruments) and
a nitrogen purge at 60 mL min−1. The sample was weighed
in an open aluminium crucible with a cross section area of
0.327 cm2 and deposited in a platinum pan. The sample size
was about 5–9 mg in order to cover the whole of the cru-
cible section uniformly. The thermobalance was calibrated
for temperature with the melting of tin. The magnitude and
linearity of the balance response were checked with standard
milligram masses.
˚
graphite monochromated Mo K␣ radiation, λ = 0.71069 A
and ω–θ scans. Three standard reflections were checked
every 100 reflections without any intensity decay. Cell
measured up to θmax = 25◦ within the four octants hkl,
hkl, hkl, hkl. The structure was solved by direct methods
using the program SHELXS97 [8] and refinement was
carried out using SHELXL97 [9]. The absorption effects
(µ = 0.21 mm−1, transmission factors varying from 0.92
to 0.99) were corrected using the numerical procedure
provided by SHELX-76 program [10]. Intensities of equiv-
alent reflections were merged (Rint = 0.0336) into 3005
(from which 1635 with I > 2σ(I)) independent reflections
used for refinements. The final refinement was carried
out to R = 0.0504, ωR(F2) = 0.1509, weighting scheme
The non-isothermal TGA was recorded at 5 ◦C min−1
from room temperature to 450 ◦C.
¯
¯ ¯ ¯
2.6. Polymorph screening
Recrystallization of 1 was performed in the following
solvents: ethyl acetate, acetonitrile, methanol, ethanol, iso-
propanol, tetrahydrofuran, acetone. Sample was suspended
into 5 mL solvent and was stirred in an oil bath at 60 ◦C. Sol-
vent was added until dissolution. The solutions were cooled
at room temperature and filtered when 1 precipitated oth-
erwise solutions were cooled at +4 ◦C until crystallization
(24 h). Powders were analyzed by X-ray powder diffraction
and DSC.
Slurry conversion studies were realized in water. A satu-
rate solution was prepared with 100 mg of 1 and 0.75 mL of
water in vials closed with a screw stopple. The suspension
wasstirred16 hat45 ◦C, 150 rpm, withaNewBrunswickSci-
ω = 1/[σ2(F02) + (0.0706P)2]
where
P = (F02 + 2Fc2)/3,
S = 1.00. Extinction coefficient was refined to 0.006(2).
Hydrogen atoms attached to carbon are treated as riding,
following the SHELXL97 HFIX/AFIX instructions; they
were given an isotropic displacement parameter equal to
1.2 times the Ueq of the parent C atom. The hydrogen
atoms attached to nitrogen and oxygen were positioned
from a Fourier difference map, and both their positions