J Chem Crystallogr (2011) 41:386–390
389
(30 mL) was added and the product was extracted with
CH2Cl2 (2 9 30 mL). The organic phase was washed with
5% aq NaHCO3 (30 mL), dried over Na2SO4 and con-
centrated. The solid was recrystallized from hexane/
CH2Cl2 affording a yellowish powder (4.4 g, 68%): mp
Table 2 Crystallographic data for 3a, 3b, and 4a
3a 3b
4a
Empirical formula
Formula mass
Crystal system
Space group
T (K)
C13H13NO2 C8H8F3NO2 C13H11NO
215.24
Monoclinic
P 21/n
207.15
197.23
Monoclinic
P 21/n
1
Triclinic
P -1
111–112 °C (112–113 °C [16]); H NMR: d 1.89 (s, 3H),
7.20–7.47 (m, 7H), 7.55 (dd, 1H, J = 2.0 and 8.0 Hz), 8.08
(br s, 1H), 8.16 (dd, 1H, J = 1.1 and 6.4 Hz); 13C NMR: d
28.9, 75.5, 123.9, 124.5, 124.7, 127.0, 127.3, 128.1, 140.4,
145.2, 153.8; MS (EI): m/z (%): 200 (15) [M?–Me].
150(2)
5.7416(1)
14.3841(4)
13.2821(3)
90
150(2)
293(2)
˚
a (A)
6.1209(2)
8.1938(4)
9.4675(4)
73.363(3)
73.166(3)
71.659(3)
421.32(3)
2
9.3579(3)
12.7340(3)
9.8579(3)
90
˚
b (A)
˚
c (A)
a-Trifluoromethyl-a-(2-pyridyl-N-oxide)ethanol (3b)
a (°)
b (°)
c (°)
94.918(2)
90
117.3249(15)
90
To 2b (1.0 g, 5.2 mmol) in CH2Cl2 (20 mL), mCPBA
(55% in H2O, 2.1 g, 6.76 mmol) was added at 0 °C under
stirring. After stirring at rt for 6 h, satd aq NaHCO3 was
added to the mixture followed by sodium bisulfite solution.
The aqueous phase was extracted with CH2Cl2
(2 9 30 mL), dried over Na2SO4 and concentrated. The
solid was purified by chromatography on silica gel eluting
first with CH2Cl2 then with AcOEt affording a white
3
˚
V (A )
1092.90(4)
4
1043.63(5)
4
Z
Dcalc (g/cm3)
1.308
1.633
1.255
˚
k (A)
0.71073
0.089
0.71073
0.160
0.71073
0.080
l (mm-1
)
Collected reflections
4647
3463
4635
Unique reflections, Rint 2486, 0.0158 1909, 0.0171 2382, 0.0182
1
powder (0.89 g, 83%): mp 92–93 °C; H NMR: d 1.83
Observed reflections
R1 [I [ 2r(I)]
wR2 [all data]
2023
1566
1724
(s, 3H), 7.42–7.58 (m, 3H), 8.28 (m, 1H), 10.34 (s, 1H);
13C NMR: d 21.7 (q, J = 1.7 Hz), 76.1 (q, J = 28 Hz),
125.0 (q, J = 284 Hz), 126.0 (q, J = 1.5 Hz), 126.1,
128.4, 140.8, 145.7; 19F NMR: d -80.5 (s).
0.0411
0.1084
0.0378
0.1022
0.0450
0.1229
structure solution program SHELXS [24]. The positions of
the remaining non-hydrogen atoms were located by use of a
combination of least-squares refinement and difference
Fourier maps in the SHELXL-97 program [24]. Non-
hydrogen atoms were refined anisotropically. The hydroxy
hydrogen atoms of 3a and 3b, located in the final stages of
the refinement from the difference Fourier maps, were
refined with isotropic displacement parameters. The
remaining hydrogen atoms were included in the structure-
factor calculations at idealized positions. All the calcula-
tions were performed using the WinGX [25]. Figures
depicting the structures were prepared by ORTEP3 [26] and
SHELXTL [27]. Cell parameters and refinement results are
summarized in Table 2. Further details on the crystal
structure investigations may be obtained from The Cam-
CCDC-764890 (for 3a), CCDC-764891 (for 3b) and
CCDC-764892 (for 4a).
a-(2-Pyridyl-N-oxide)styrene (4a)
A mixture of 3a (2.15 g, 10 mmol) and 85% H2SO4 (8 mL)
was stirred at 100 °C for 20 min, cooled to rt then poured
onto ice-water (100 g). The product was extracted with
CH2Cl2 (10 9 10 mL), dried, filtered through a short pad
of silica gel and concentrated affording yellowish crystals
(1.38 g, 70%): mp 128–130 °C; 1H NMR: d 5.66
(d, J = 0.6 Hz, 1H; C = CHaHb), 5.95 (d, J = 0.6 Hz,
1H; C = CHaHb), 7.23–7.42 (m, 8H; Ar–H), 8.24 (m, 1H;
Ar–H); 13C NMR: d 119.3, 125.0, 125.1, 125.8, 127.8,
128.1, 128.5, 137.6, 140.2, 142.6, 150.3; MS (EI) m/z [M?]
197 (41%); HRMS (EI) m/z: calcd. for C13H11NO [M?]
197.0859, found 197.0846.
X-Ray Crystallography
The crystals were mounted on the tip of glass fibres with a
small amount of silicon grease and transferred to a goni-
ometer head. Data were collected on a Nonius Kappa CCD
diffractometer using graphite monochromated Mo Ka radi-
ation. Data reduction and integration were performed with
the software package DENZO-SMN [23]. Averaging of the
symmetry-equivalent reflections largely compensated for
the absorption effects. The coordinates of some or all of the
non-hydrogen atoms were found via direct methods using the
References
1. Denmark SE, Fan Y (2006) Tetrahedron Asymmetry 17:687 and
references cited therein
ˇ
2. Stephan M, Sterk D, Mohar B (2009) Adv Synth Catal 351:2779
123