1200
LEVOV et al.
column was calibrated using dextran standards with
molecular weights of 1080, 4440, 9890, 43500, 66700,
123600, and 196300 kDa (Sigma).
Methyl 6-bromo-3-fluoroimidazo[1,2-a]pyridine-
2-carboxylate (IVd) was synthesized according to the
procedure described in [9] from 0.1 mol of methyl 2-
(5-brompyridin-2-ylimino)-3,3,3-trifluoropropionate
and 0.1 mol of trimethyl phosphite. Yield 71%, mp
Methyl 3,3,3-trifluoro-2-(3-methylpyridin-2-yl-
imino)propionate (IIIb) was synthesized according to
the procedure described in [9] from 0.1 mol of 3-
methylpyridin-2-amine and 0.1 mol of methyl 3,3,3-
trifluoro-2-oxopropionate. Yield 75%, bp 97–98°C
(5 mm). 1H NMR spectrum (DMSO-d6), δ, ppm: 2.49 s
(3H, Me), 3.98 s (3H, MeO), 6.98 t (1H, Harom, J =
6.9 Hz), 7.11 d (1H, Harom, J = 6.9 Hz), 7.75 d (1H,
1
175–177°C. H NMR spectrum (DMSO-d6), δ, ppm:
3.96 s (3H, MeO), 6.83 d (1H, Harom, J = 8.0 Hz), 7.62
d (1H, Harom, J = 8.0 Hz), 7.95 s (1H, Harom). 19F NMR
spectrum (DMSO-d6): δF –67.21 ppm, d (1F, J = 1.9 Hz).
Found, %: C 39.38; H 2.02; N 10.04. C9H6BrFN2O2.
Calculated, %: C 39.59; H 2.21; N 10.26.
arom, J = 6.9 Hz). 19F NMR spectrum (DMSO-d6): δF
Methyl 6-chloro-3-fluoroimidazo[1,2-a]pyridine-
2-carboxylate (IVe) was synthesized according to the
procedure described in [9] from 0.1 mol of methyl 2-
(5-chloropyridin-2-ylimino)-3,3,3-trifluoropropionate
and 0.1 mol of trimethyl phosphite. Yield 79%, mp
H
8.02 ppm. Found, %: C 48.61; H 3.87; N 11.25.
C10H9F3N2O2. Calculated, %: C 48.79; H 3.68; N 11.38.
Methyl 3,3,3-trifluoro-2-(5-bromopyridin-2-yl-
imino)propionate (IIId) was synthesized according to
the procedure described in [9] from 0.1 mol of 5-
bromopyridin-2-amine and 0.1 mol of methyl 3,3,3-
trifluoro-2-oxopropionate. Yield 75%, bp 81–82°C
(1 mm). 1H NMR spectrum (DMSO-d6), δ, ppm: 3.89 s
(3H, MeO), 6.71 d (1H, Harom, J = 8.2 Hz), 7.53 d (1H,
1
169–171°C. H NMR spectrum (DMSO-d6), δ, ppm:
6.91 d (1H, Harom, J = 8.7 Hz), 7.51 d (1H, Harom, J =
8.7 Hz), 7.89 s (1H, Harom). 19F NMR spectrum
(DMSO-d6): δF –66.29 ppm, d (1F, J = 1.8 Hz). Found,
%: C 47.52; H 2.81; N 17.16. C9H6ClFN2O2.
Calculated, %: C 47.29; H 2.65; N 17.33.
H
arom, J = 8.2 Hz), 7.83 s (1H, Harom). 19F NMR
3-Fluoroimidazo[1,2-a]pyridine-2-carboxylic
acid hydrochloride (Va) was synthesized according to
the procedure described in [9] from 0.1 mol of methyl
3-fluoroimidazo[1,2-a]pyridine-2-carboxylate. Yield
spectrum (DMSO-d6): δF 8.19 ppm. Found, %: C
34.92; H 2.12; N 9.23. C9H6BrF3N2O2. Calculated, %:
C 34.75; H 1.94; N 9.01.
1
87%, mp 215–216°C. H NMR spectrum (DMSO-d6),
Methyl 3,3,3-trifluoro-2-(5-chloropyridin-2-yl-
imino)propionate (IIIe) was synthesized according to
the procedure described in [9] from 0.1 mol of 5-
chloropyridin-2-amine and 0.1 mol of methyl 3,3,3-
trifluoro-2-oxopropionate. Yield 75%, bp 118–119°C
(5 mm). 1H NMR spectrum (DMSO-d6), δ, ppm: 3.82 s
(3H, MeO), 6.89 d (1H, Harom, J = 8.8 Hz), 7.42 d (1H,
Harom, J = 8.8 Hz), 7.91 s (1H, Harom). 19F NMR
spectrum (DMSO-d6): δF 8.12 ppm. Found, %: C
40.74; H 2.12; N 10.23. C9H6ClF3N2O2. Calculated, %:
C 40.55; H 2.27; N 10.51.
δ, ppm: 7.26 t (1H, Harom, J = 7.9 Hz), 7.65 m (2H,
H
arom), 8.52 d (1H, Harom, J = 7.9 Hz). 19F NMR spec-
trum (DMSO-d6): δF –63.33 ppm, s (1F) Found, %: C
44.58; H 2.63; N 13.16. C8H5ClFN2O2. Calculated, %:
C 44.36; H 2.79; N 12.93.
3-Fluoro-8-methylimidazo[1,2-a]pyridine-2-car-
boxylate hydrochloride (Vb) was synthesized accord-
ing to the procedure described in [9] from 0.1 mol of
methyl 3-fluoro-8-methylimidazo[1,2-a]pyridine-2-
1
carboxyylate. Yield 91%, mp 213–214°C. H NMR
spectrum (DMSO-d6), δ, ppm: 2.50 s (3H, Me), 7.16 t
(1H, Harom, J = 7.9 Hz), 7.40 d (1H, Harom, J = 7.9 Hz),
8.37 d (1H, Harom, J = 7.9 Hz). 19F NMR spectrum
(DMSO-d6): δF –64.59 ppm, d (1F, J = 1.9 Hz). Found,
%: C 46.68; H 3.72; N 12.36. C9H7ClFN2O2. Cal-
culated, %: C 46.87; H 3.50; N 12.15.
Methyl
3-fluoro-8-methylimidazo[1,2-a]pyri-
dine-2-carboxylate (IVb) was synthesized according
to the procedure described in [9] from 0.1 mol of
methyl 3,3,3-trifluoro-2-(3-methylpyridin-2-ylimino)
propionate and 0.1 mol of trimethyl phosphite. Yield
1
73%, mp 142–144°C. H NMR spectrum (DMSO-d6),
δ, ppm: 2.54 s (3H, Me), 3.93 s (3H, MeO), 6.90 t (1H,
6-Bromo-3-fluoroimidazo[1,2-a]pyridine-2-car-
boxylic acid hydrochloride (Vd) was synthesized
according to the procedure described in [9] from
0.1 mol of methyl 6-bromo-3-fluoroimidazo[1,2-a]-
pyridine-2-carboxylate. Yield 93%, mp 265–266°C. 1H
H
arom, J = 6.7 Hz), 7.05 d (1H, Harom, J = 6.7 Hz), 7.99
d (1H, Harom, J = 6.7 Hz). 19F NMR spectrum (DMSO-
d6): δF –65.59 ppm, d (1F, J = 1.9 Hz). Found, %: C
57.47; H 4.53; N 13.16. C16H12F3N5O3S. Calculated,
%: C 57.69; H 4.36; N 13.36.
NMR spectrum (DMSO-d6), δ, ppm: 7.59 d (1H, Harom
,
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 81 No. 6 2011