PRACTICAL SYNTHETIC PROCEDURES
Reductive Aminations on Millimolar and Molar Scale
1759
temperature was kept below 20 °C. The mixture was stirred over- References
night at r.t. The borane complex was not isolated. The solvent was
(
1) (a) Greenwood, B.; Mutabingwa, T. Nature 2002, 415, 670.
b) Ridley, R. G. Nature 2002, 415, 686. (c) Schlitzer, M.
ChemMedChem 2007, 2, 944. (d) Schlitzer, M. Arch.
Pharm. (Weinheim, Ger.) 2008, 341, 149.
2) (a) Borrmann, S.; Adegnika, A. A.; Matsiegui, P.-B.; Issifou,
S.; Schindler, A.; Mawilli-Mboumbe, D. P.; Baranek, T.;
Wiesner, J.; Jomaa, H.; Kremsner, P. G. J. Infect. Dis. 2004,
evaporated at the rotary evaporator and the residue was used as re-
ducing agent in the next step. The methanolic solution of benzyl-
oxyiminopropylphosphonic acid diethyl ester (5), prepared as
above, was added dropwise to the reducing agent. Aq 32% HCl (34
mL) was added dropwise with ice cooling and the mixture was
stirred overnight. The pH was adjusted to 10 with aq KOH and the
solution was extracted with EtOAc (3 × 250 mL). The combined ex-
tracts were dried (Na SO ) and the solvent was evaporated to afford
(
(
189, 901. (b) Borrmann, S.; Issifou, S.; Esser, G.; Adegnika,
2
4
A. A.; Ramharter, M.; Matsiegui, P.-B.; Oyakhirome, S.;
Mawilli-Mboumbe, D. P.; Missimou, M. A.; Kun, J. F. J.;
Jomaa, H.; Kremsner, P. G. J. Infect. Dis. 2004, 190, 1534.
2
3.08 g of 6 (76.6 mmol, 92%). Spectroscopic data matched with
4
the literature data.
IR (film): 3247 (NH), 3032, 2982, 2908 cm–1 (CH).
(
c) Borrmann, S.; Lundgren, I.; Oyakhirome, S.; Impouma,
1
3
H NMR (500 MHz, CDCl ): d = 1.31 (t, J = 7.1 Hz, 6 H, 2 × CH ),
B.; Matsiegui, P.-B.; Adegnika, A. A.; Issifou, S.; Kun, H. F.
J.; Hutchinson, D.; Wiesner, J.; Jomaa, H.; Kremsner, P. G.
Antimicrob. Agents Chemother. 2006, 2713.
(d) Oyakhirome, S.; Issifou, S.; Bongratz, P.; Barondi, F.;
Ramharter, M.; Kun, J. F.; Missinou, M. A.; Lell, B.;
Kremsner, P. G. Antimicrob. Agents Chemother. 2007, 1869.
3
3
3
1
4
5
.78–1.90 (m, 4 H, PCH CH ), 2.97 (t, J = 6.5 Hz, 2 H, NCH ),
2
2
2
.03–4.14 (m, 4 H, 2 × POCH ), 4.68 (s, 2 H, OCH ), 7.27–7.36 (m,
2
2
H, ArH).
1
3
3
C NMR (125 MHz, CDCl ): d = 16.42 (d, J = 6.0 Hz, 2 × CH ),
3
C-P
3
0.58 (d, 2
1
2
J
= 4.8 Hz, PCH CH ), 23.19 (d,
J = 142 Hz,
C-P
2
2
C-P
3
2
(3) Wiesner, J.; Borrmann, S.; Jomaa, H. Parasitol. Res. 2003,
0, 71.
PCH ), 52.09 (d, J = 17.2 Hz, NCH ), 61.43 (d, J = 6.7 Hz,
2
C-P
2
C-P
9
2
× POCH ), 76.33 (OCH ), 127.78, 128.34, 128.42 (CH ), 137.82
Ar
2
2
Ar
(
4) (a) Kurz, T.; Geffken, D.; Wackendorff, C. Z. Naturforsch.,
B 2002, 58, 106. (b) Ortmann, R.; Wiesner, J.; Reichenberg,
A.; Henschker, D.; Beck, E.; Jomaa, H.; Schlitzer, M. Arch.
Pharm. Chem. Life Sci. 2005, 338, 305. (c) Ortmann, R.;
Wiesner, J.; Silber, K.; Klebe, G.; Jomaa, H.; Schlitzer, M.
Arch. Pharm. Chem. Life Sci. 2007, 340, 483.
(
C ).
3
1
P NMR (161 MHz, CDCl ): d = 32.76.
3
Acknowledgment
(
d) Perruchon, J.; Ortmann, R.; Schlitzer, M. Synthesis 2007,
This publication was generated in the context of the AntiMal pro-
ject, funded under the 6 Framework of the European Community
th
3553.
(
(
(
5) Hutchins, R. O.; Learn, K.; Nazer, B.; Pytlewski, D. Org.
Prep. Proced. Int. 1984, 16, 335.
6) Iwasaki, Y. Shirol Yakuhin Co., Ltd., US Patent 006060623
A, 2000; Chem. Abstr. 2000, 132, 293877.
7) Manuscript in preparation.
(Contract No. IP-018834). The authors are solely responsible for its
content; it does not represent the opinion of the European Commu-
nity and the Community is not responsible for any use that might be
made of the information contained therein.
Synthesis 2009, No. 10, 1757–1759 © Thieme Stuttgart · New York