7
88
VALIULLINA et al.
(
13%) of compound 5, and 0.05 g of unreacted
H C
H
H
3
compound 2a.
H
CO Et
2
2
-Methyl 4-ethyl (2S*,3S*,4S*,5S*)-3-methyl-5-
CH3
(2-methyl-1-methoxy-1-oxopropan-2-yl)pyrrolidine
-2,4-dicarboxylate (4). IR spectrum, cm : 2979,
2907, 1733, 1178. Н NMR spectrum (CDCl ), δ, ppm:
H
–
1
CH3
N
MeO C
H
1
2
CO Me
3
2
NOE-interactions in compound 4.
1.20 d (3Н, СН
3
, J 6.9 Hz), 1.24 t (3Н, СН
3
, J 7.1 Hz),
1
.30 s (3Н, СН ), 1.32 s (3Н, СН ), 2.57‒2.63 m (2Н,
3
3
2
5
Methyl (Е)-2,2-dimethyl-3-[(methoxycarbonyl)-
methylimino]propanoate (3). To a solution of 0.58 g
4.62 mmol) of methyl glycinate hydrochloride in
mL of water was added a solution of 0.95 g
6.93 mmol) of K CO in 4 mL of water. The mixture
СН), 3.33 d (1Н, H , J 5.8 Hz), 3.35 d (1Н, H , J 6.3
Hz), 3.68 s (3Н, OCH
(1Н, ОСН , J 7.1, 3.7 Hz), 4.06 d.d (1Н, ОСН
2
), 3.77 s (3Н, OCH
), 4.00 d.d
, J 7.2,
), δ, ppm: 13.84
), 24.37 (СН ), 43.63
3
3
(
1
(
2
3
1
3.6 Hz). С NMR spectrum (CDCl
(CН ), 20.02 (СН ), 23.68 (СН
(С ), 51.85 and 52.11 (ОСН ), 53.39 (С ), 60.63
3
3
2
3
3
3
3
3
4
3
was stirred for 5 min, methyl glycinate was extracted
with CH Cl , the combined organic extracts were dried
2
5
(ОСН
176.40 (2CO
%): 316 [M + H] (100). Found, %: С 57.35; Н 7.87; N
4.52. C15 . Calculated, %: С 57.13; Н 7.99; N 4.44.
), 67.44 (С ), 68.59 (С ); 173.09, 173.71,
2
2
2
with MgSO , filtered off, and evaporated. The residue
2
Me, CO Et). Mass spectrum, m/z (Irel,
2
4
+
was added to a solution of 0.40 g (3.08 mmol) of
methyl 2,2-dimethyl-3-oxopropanoate [7] in toluene
and the mixture was boiled till the end of water
liberation. The reaction mixture was washed with
H
25NO
6
Methyl (2S*,3S*)-3-methyl-5-oxopyrrolidine-2-
–1
carboxylate (5). IR spectrum, cm : 3349‒3112, 2960,
brine, dried with MgSO , evaporated, and the residue
1
4
1
731, 1691, 1672, 1212. Н NMR spectrum (CDCl ),
3
was additionally dried for 5 h in a vacuum (2 mm Hg)
4
δ, ppm: 1.38 d (3Н, СН , J 6.5 Hz), 2.03 q (1Н, Н , J
1
3
at 20°С. Yield 0.40 g (70%). Н NMR spectrum
3
4
2
1
5
0.0 Hz), 2.55 m (2Н, H , H ), 3.70 d (1Н, H , J
(
CDCl ), δ, ppm: 1.38 s (6H, CH ), 3.71 s (3H,
13
3
3
.2 Hz), 3.75 s (3Н, OCH ), 6.63 br.s (1H, NH).
С
3
CO Me), 3.72 s (3H, CO Me), 4.21 s (2H, CH ), 7.79 s
2
2
2
NMR spectrum (CDCl ), δ, ppm: 20.04 (СН ), 34.02
13
3
3
(
(
(
(
1H, =CH). С NMR spectrum, CDCl , δ, ppm: 22.64
CH ), 51.96 and 52.21 (OCH ), 47.82 (C ), 61.18
3
4
2
3
(
С ), 37.88 (С ), 52.47 (ОСН ), 62.41 (С ), 172.13 and
2
3
3
3
1
1
77.11 (CO , CONH). Mass spectrum, m/z (I , %):
2 rel
99 [M + MeCN] (100), 158 [M + H] (40).
CH N), 170.19 (CO Me), 170.57 (CH=N), 175.0
+
+
2
2
CO Me). Found, %: С 53.95; Н 7.63; N 7.02.
2
C H NO . Calculated, %: С 53.72; Н 7.51; N 6.96.
IR spectra were recorded on a spectrophotometer
9
15
4
1
13
IR Prestige-21 Shimadzu from thin film. Н and
С
Reaction of ethyl 3-tert-butyl(dimethyl)sililoxy]-
butanoate (2a) and compound (3). To a solution of
.11 g (1.10 mmol) of i-Pr NH in 5 mL of anhydrous
NMR spectra were registered of spectrometers Bruker
AM-300 at operating frequencies 300.13 and
0
2
7
5.47 МHz and Bruker Avance-500 at operating
THF at ‒78°С under an argon atmosphere was added
.47 mL (1.00 mmol) of 2.1 N solution of BuLi. The
frequencies 500.13 and 125.77 МHz respectively,
internal reference TMS. Mass spectra were taken on an
instrument LCMS-2010EV (Shimadzu). Elemental
analysis of synthesized compounds was carried out on
a CHN-analyzer Evro EA-2000. The reaction progress
was monitored by TLC on Sorbfil plates (Russia),
spots visualized by adding solution of anisaldehyde
and sulfuric acid in ethanol followed by heating at 120–
0
reaction mixture was stirred for 20 min at ‒10°С, then
at ‒78°С 0.25 g (1.00 mmol) of compound 2a was
added dropwise. The mixture was stirred for 1.5 h at
‒
20°С, then the reaction mixture was cooled to ‒78°С
and 0.20 g (1.00 mmol) of imine 3 solution in 1 mL of
anhydrous THF was added dropwise. The reaction
mass was stirred for 1.5 h at ‒20°С, then at room
temperature it was treated with saturated water
1
50°С. The products of synthesis were isolated by
column chromatography on silica gel (30‒60 g of
adsorbent per 1 g of compound).
solution of NH Cl (4 mL). The reaction product was
4
extracted with ethyl acetate, the combined organic
extracts were washed with brine and dried with
ACKNOWLEDGMENTS
MgSO . On distilling off the solvent in a vacuum and pu-
4
rifying the residue by column chromatography on SiO2
In the study the equipment was used of the Center
of joint usage of the Ufa Institute of Chemistry,
Russian Academy of Sciences.
(
eluent petroleum ether–ethyl-acetate, 95 : 5→1 : 1)
we isolated 0.09 g (30%) of compound 4, 0.02 g
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 53 No. 5 2017