972
C. A. Escobar et al. · Regioselective N-Acetylation of a Benzodiazepine
7.11 (1H, d, J = 7.6 Hz, Harom), 7.26 – 7.44 (8H, m, Harom), X-Ray crystal structure determination
7.50 (1H, t, J = 7.6 Hz), 7.67 (1H, d, J = 8.0 Hz), 14.3 (1H,
For both compounds data collection, cell refinement and
s, OH). – 13C NMR (400 MHz, CDCl3): δ = 23.3, 34.1,
66.9, 118.3, 118.8, 119.1, 126.0, 126.8, 126.9, 128.4, 128.9,
128.94, 129.6, 130.9, 131.7, 134.3, 140.1, 144.3, 162.8,
170.5, 174.8.
data reduction were done with CRYSALIS CCD (V.1.171.
32.15). The structures were solved by Direct Methods with
SHELXS-97 [10], completed by difference Fourier synthe-
ses and refined with SHELXL-97 [10]. The positions of hy-
drogen atoms were calculated after each cycle of refinement
with SHELXL-97 using a riding model for each structure,
1-Acetyl-4-(2-acetoxyphenyl)-2-phenyl-2,3-dihydro-1H-1,5-
benzodiazepine (2)
˚
with C–H distances in the range 0.93 to 0.98 A. Uiso(H) val-
ues were set equal to 1.5 Ueq of the parent carbon atom for
methyl groups and 1.2 Ueq for the others and for O–H. Com-
pound 1 crystallizes in the non-centrosymmetric space group
Cc with Z = 8 molecules in the unit cell. Checks of the met-
rical symmetry of the lattice and the coordinate set with the
program MISSYM as incorporated in PLATON did not indi-
cate any higher symmetry [11]. Details of the crystal struc-
ture determination and refinement are given in Table 1. In
Tables 2 and 3 selected bond lengths and angles for 1 and
2 and the hydrogen bond parameters for 1 are summarized,
respectively.
4-(2-Hydroxyphenyl)-2-phenyl-2,3-dihydro-1H-1,5-
benzodiazepine (1.0 g) was refluxed for 0.5 h in excess
acetic anhydride (100 mL). Then the mixture was allowed
to cool to ambient temperature, and concentrated in a
rotatory evaporator. The mixture obtained was subjected
to column chromatography (silica gel 60, ethyl acetate:
hexane = 1 : 10 v/v). The fraction that resulted to be a solid
was collected and crystallized from methanol: light-yellow
crystals (0.627 g; 50 %), m. p. 166.5 – 168.1 ◦C. – IR (KBr):
ν = 1740 (CO), 1670 (N-CO), 1344 (O-CO) cm−1. –
1H NMR (400 MHz, CDCl3): δ = 1.80 (3H, s, COCH3),
2.35 (3H, s, COCH3), 3.00 – 3.06 (2H, m, CH2), 6.53 (1H,
dd, J = 12 Hz, J = 6.6 Hz, CH), 7.06 (1H, dd, J = 7.6 Hz,
J = 1.2 Hz, Harom), 7.1 – 7.3 (9H, m, Harom), 7.45 – 7.50
(2H, m, Harom), 7.74 (1H, dd, J = 8 Hz, J = 1.6 Hz Harom). –
13C NMR (400 MHz, CDCl3): δ = 21.5, 23.1, 38.1, 66.8,
123.7, 125.8, 126.3, 126.4, 126.9, 128.2, 128.9, 129.4,
130.0, 130.7, 130.8, 131.4, 132.6, 140.1, 147.3, 148.5,
169.3, 170.5, 170.7.
CCDC 716546 and 716547 contain the supplementary
crystallographic data for this paper. These data can be ob-
tained free of charge from The Cambridge Crystallographic
Acknowledgement
This work was supported by Fondecyt through Grant
1080147, awarded to C. A. E. and Universidad Andres Bello
trough grant N◦DI-UNAB-20-06/R.
[7] C. A. Escobar, O. Donoso-Tauda, R. Araya-Maturana,
A. Vega, Acta Cryst. 2007, C63, o426–o430.
[8] Y. K. Srivastava, B. L. Verma, Nat. Acad. Sci. Lett.
1990, 13, 55 – 57.
[9] C. A. Escobar, O. Donoso-Tauda, R. Araya-Maturana,
D. Sicker, Synth. Comm. 2009, 39, 166 – 174.
[10] G. M. Sheldrick, SHELXS/L-97, Programs for Crys-
tal Structure Determination, University of Go¨ttingen,
Go¨ttingen (Germany) 1997; see also: G. M. Sheldrick,
Acta Cryst. 2008, A64, 112 – 122.
[11] A. L. Spek, PLATON, A. Multipurpose Crystallo-
graphic Tool, Utrecht University, Utrecht (The Nether-
lands) 2000; see also: A. L. Spek, J. Appl. Crystallogr.
2003, 36, 7 – 13.
[1] T. Kurahashi, T. Mizutani, J. Yoshida, J. Chem. Soc.,
Perkin Trans. 1999, 1, 465 – 473.
[2] N. Moitessier, P. Englebenne, Y. Chapleur, Tetrahedron
2005, 61, 6839 – 6853.
[3] T. Kawabata, W. Muramatsu, T. Nishio, T. Shibata,
H. Schedel, J. Am. Chem. Soc. 2007, 129, 12890 –
12895.
[4] N. Armesto, S. Ferna´ndez, M. Ferrero, V. Gotor, Tetra-
hedron 2006, 62, 5401 – 5410.
[5] Y. Tachibana, H. Kawasaki, N. Kihara, T. Takata,
J. Org. Chem. 2006, 71, 5093 – 5104.
[6] E. Husson, C. Humeau, F. Blanchard, X. Framboisier,
I. Marc, I. Chevalot, J. Mol. Catal. B: Enzymatic 2008,
55, 110 – 117.
Brought to you by | NDSU Library Periodicals
Authenticated
Download Date | 6/10/15 4:55 PM