SYNTHESIS OF AN UNSATURATED -ALANINE DERIVATIVE
1001
1H NMR spectrum (300 MHz, acetone-d6), , ppm:
1.41 s (9H, t-C4H9), 2.52 m (2H, C_H2NH), 3.34 m
(2H, COC_H2), 3.6 s (3H, OCH3).
rator for 7 days. After that, the mixture was diluted
with 30 ml of methylene chloride and washed with
water. The organic layer was dried over Na2SO4 and
concentrated. The product was obtained as a white
crystalline substance; yield 1.54 g (87%).
Found, %: C 53.32, H 8.71, N 6.73.
C9H17NO4.
1
IR spectrum, , cm : 3300, 3085, 1689, 1668
1
Calculated, %: C 53.19, H 8.43, N 6.89.
(C=O, amide I), 1540 (C=O, amide II). H NMR
spectrum (300 MHz, acetone-d6), , ppm: 1.4 s (9H),
3.25 3.44 m (6H), 3.8 m (2H), 5.58 d.d (1H), 6.2 m
(2H).
Amine IV. Methyl 3-tert-butyloxycarbonylamino-
propionate III (3.48 g, 17 mmol) was dissolved in
30 ml of methanol, and a solution of 30 ml of ethyl-
enediamine in 60 ml of methanol was slowly added
dropwise with stirring. The reaction was performed
at room temperature in the dark for 5 days. Then the
mixture was evaporated. The product was purified by
column adsorption chromatography on silica gel (40
60 m), with methylene chloride as eluent. The prod-
uct was obtained as an oil; yield 2.94 g (75%).
Found, %: C 54.87, H 8.21, N 14.83.
C13H23N3O4.
Calculated, %: C 54.72, H 8.12, N 14.73.
Free-radical copolymerization of GMA, EDMA,
and the acrylic monomer (molar ratio 5.4 : 4 : 0.6)
was performed under the photoinitiation conditions in
cyclohexanol dodecanol (7 : 3) in the presence of
2% Darocure 1173. The reaction time was 1 h. After
the reaction was complete, the products were washed
with ethanol and dried at 100 C.
1H NMR spectrum (300 MHz, acetone-d6), , ppm:
1.41 s (9H, t-C4H9), 2.31 2.46 m (2H), 3.24 3.33 m
(4H), 3.34 3.45 m (2H).
Found, %: C 52.12, H 9.26, N 18.05.
C10H21N3O3.
Thermal copolymerization of GMA, EDMA, and
the acrylic monomer (molar ratio 5.4 : 4 : 0.6) was
performed in 2-propanol at 60 C, with 1% 2,2 -azo-
bis(isobutyronitrile) as initiator, following the proce-
dure described in [5]. The reaction time was 3 h.
After the reaction was complete, the polymers were
washed with ethanol and dried at 100 C.
Calculated, %: C 51.93, H 9.15, N 18.17.
Monomer V. To a solution of 1.43 g (6.2 mmol)
of IV in 20 ml of methylene chloride, cooled with
a mixture of ice and NaCl, we added with stirring
1.1 ml of triethylamine. Then we added dropwise a
solution of 0.6 ml of acryloyl chloride in 5 ml of
methylene chloride. The mixture was kept in a refrige-
The synthesis of the acrylic derivative of -alanine
with a protected amino group involved several steps:
SOCl2
Boc2O
NH2
O
NH3Cl
O
NHBoc
HO
MeOH
NEt3
O
O
O
I
II
III
O
H
H
N
COCl
NH2CH2CH2NH2
MeOH
N
NHBoc
NHBoc
NH3, CH2Cl2
N
H2N
H
O
O
IV
V
In the first step, the carboxy group of amino acid
I was protected by conversion into methyl ester II.
The reaction was performed in methanol in the pres-
ence of thionyl chloride [6].
the attempted protection in aqueous dioxane in the
presence of NaOH is accompanied by saponification
of the ester. Therefore, the Boc protection of the ami-
no group in II was performed in the presence of
a milder base, triethylamine [7]. The reaction was per-
formed in methanol for 0.5 h at 50 C.
The amino group of -alanine methyl ester hydro-
chloride was protected with di-tert-butyl pyrocarbo-
nate (Boc2O). This reaction can be performed in
aqueous organic or organic media [6]. We found that
Boc-protected -alanine ester III was converted to
ethylenediamine derivative IV by the reaction with
RUSSIAN JOURNAL OF APPLIED CHEMISTRY Vol. 78 No. 6 2005