4-(3-DIALKYLAMINO-2,5-DIOXOPYRROLIDIN-1-YL)BENZOIC ACID ESTERS
395
(C=O), 1230 (COC). Found, %: C 65.42; H 5.04;
N 4.86. C15H15NO4. Calculated, %: C 65.93; H 5.53;
N 5.13.
mp 166–168°C (from dioxane and EtOH), Rf 0.56. IR
spectrum, ν, cm–1: 3450, 1750, 1690 (C=O), 1245
(COC). Found, %: C 60.99; H 5.91; N 7.82.
C17H20N2O5. Calculated, %: C 61.44; H 6.06; N 8.43.
Alkyl 4-(3-dialkylamino-2,5-dioxo-2,3,4,5-tetra-
hydro-1H-pyrrol-1-yl)benzoates Va–Vk (general
procedure). A solution of 0.015 mol of amine IVa–IVc
in 5 ml of dioxane was gradually added to a solution of
0.015 mol of imide IIIa–IIId in 5 ml of dioxane, and
the mixture was stirred for 2–4 h at 18–20°C and then
heated for 1 h at 45–50°C (in the reactions with di-
ethylamine) or at 60–90°C (in the reactions with piper-
idine and morpholine). The mixture was cooled and
diluted with 100–200 ml of water, and the precipitate
was filtered off, washed with water (10×5 ml), and
dried. Compounds Vd and Ve separated from the reac-
tion mixture (ester Vb separated only partially), while
ester Vi was isolated by evaporation of the mixture. All
compounds Va–Vk were purified by recrystallization.
2-Chloroethyl 4-(3-diethylamino-2,5-dioxo-
2,3,4,5-tetrahydro-1H-pyrrol-1-yl)benzoate (Vf).
Yield 75%, mp 78–80°C (from EtOH), Rf 0.65. IR
spectrum, ν, cm–1: 3450, 1735, 1660, 1640 (C=O),
1
1210 (COC). H NMR spectrum, δ, ppm: 1.03 t (6H,
3
CH3, JHH = 8 Hz), 2.25 m (4H, CH2), 2.78 d.d and
2.97 q (2H, CH2CO), 3.98 t (2H, CH2Cl, 3JHH = 6 Hz),
3
4.30 q (1H, CHCO), 4.57 t (2H, CH2O, JHH = 6 Hz),
3
7.48 d and 8.10 d (2H each, Harom, JHH = 8 Hz).
Found, %: C 63.94; H 6.23; N 8.27. C17H21N2O4. Cal-
culated, %: C 64.34; H 6.66; N 8.83.
2-Chloroethyl 4-(2,5-dioxo-3-piperidino-2,3,4,5-
tetrahydro-1H-pyrrol-1-yl)benzoate (Vg). Yield
80%, mp 124–125°C (from EtOH), Rf 0.58. IR spec-
trum, ν, cm–1: 3445, 1735, 1635, 1620 (C=O), 1200
(COC). 1H NMR spectrum, δ, ppm: 1.38 m (2H, CH2),
1.50 m (4H, CH2), 2.46 m and 2.78 m (2H each,
CH2N), 2.80 d.d and 2.97 q (2H, CH2CO), 3.98 t (2H,
Methyl 4-(3-diethylamino-2,5-dioxo-2,3,4,5-
tetrahydro-1H-pyrrol-1-yl)benzoate (Va). Yield
71%, mp 85–87°C. IR spectrum, ν, cm–1: 3450, 1730,
1660 (C=O), 1230 (COC). Found, %: C 62.79; H 6.58;
N 8.96. C16H20N2O4. Calculated, %: C 63.15; H 6.62;
N 9.20.
3
CH2Cl, JHH = 6 Hz), 4.04 q (1H, CHCO), 4.57 t (2H,
CH2O, 3JHH = 6 Hz), 7.47 d and 8.10 d (2H each, Harom
,
3JHH = 8 Hz). Found, %: C 65.41; H 6.33; N 8.43.
Methyl 4-(2,5-dioxo-3-piperidino-2,3,4,5-tetra-
hydro-1H-pyrrol-1-yl)benzoate (Vb). Yield 73%,
mp 179–181°C (from dioxane), Rf 0.65 (ethanol–ben-
zene, 3:1). IR spectrum, ν, cm–1: 3450, 1740, 1680,
1660 (C=O), 1230 (COC). Found, %: C 64.03; H 5.96;
N 8.27. C17H20N2O4. Calculated, %: C 64.55; H 6.37;
N 8.85.
C18H21N2O4. Calculated, %: C 65.64; H 6.42; N 8.50.
2-Chloroethyl 4-(3-morpholino-2,5-dioxo-2,3,4,5-
tetrahydro-1H-pyrrol-1-yl)benzoate (Vh). Yield
80%, mp 131–133°C (from EtOH), Rf 0.53. IR spec-
trum, ν, cm–1: 3440, 1730, 1630 (C=O), 1200 (COC).
1H NMR spectrum, δ, ppm: 2.55 m and 2.97 m (4H,
CH2N), 2.97 m and 3.02 q (2H, CH2CO), 3.60 t (4H,
Ethyl 4-(3-diethylamino-2,5-dioxo-2,3,4,5-tetra-
hydro-1H-pyrrol-1-yl)benzoate (Vc). Yield 51%,
mp 94.5–95.5°C (from EtOH), Rf 0.70. IR spectrum, ν,
cm–1: 3450, 1740, 1700 (C=O), 1260 (COC). 1H NMR
spectrum, δ, ppm: 1.03 t (6H, CH3, 3JHH = 8 Hz), 1.33 t
3
CH2OCH2), 3.98 t (2H, CH2Cl, JHH = 6 Hz), 4.06 q
3
(1H, CHCO), 4.57 t (2H, CH2O, JHH = 6), 7.48 d and
3
8.10 d (2H each, Harom, JHH = 8 Hz). Found, %:
C 61.38; H 5.56; N 8.39. C17H19N2O5. Calculated, %:
C 61.63; H 5.77; N 8.45.
3
(3H, CH3, JHH = 8 Hz), 2.63 m (4H, CH2), 2.75 d.d
and 2.96 q (2H, CH2CO), 4.28 q (1H, CHN), 4.34 q
Butyl 4-(3-diethylamino-2,5-dioxo-2,3,4,5-tetra-
hydro-1H-pyrrol-1-yl)benzoate (Vi). Yield 81%,
mp 50–52°C, Rf 0.67. IR spectrum, ν, cm–1: 3450,
1740, 1650 (C=O), 1210 (COC). Found, %: C 65.58;
H 7.44; N 8.04. C19H26N2O4. Calculated, %: C 65.89;
H 7.51; N 8.09.
(2H, CH2O, 3JHH = 7 Hz), 7.45 d and 8.07 d (2H each,
3
H
arom, JHH = 8 Hz). Found, %: C 63.91; H 6.68;
N 8.59. C17H22N2O4. Calculated, %: C 64.14; H 6.96;
N 8.80.
Ethyl 4-(2,5-dioxo-3-piperidino-2,3,4,5-tetra-
hydro-1H-pyrrol-1-yl)benzoate (Vd). Yield 49%,
mp 147–149°C (from dioxane and EtOH), Rf 0.68. IR
spectrum, ν, cm–1: 3460, 1745, 1690 (C=O), 1245
(COC). Found, %: C 65.19; H 6.28; N 8.13.
C18H22N2O4. Calculated, %: C 65.44; H 6.71; N 8.48.
Butyl 4-(2,5–dioxo-3-piperidino-2,3,4,5-tetra-
hydro-1H-pyrrol-1-yl)benzoate (Vj). Yield 84%,
mp 109–111°C (from diethyl ether), Rf 0.71. IR spec-
trum, ν, cm–1: 3455, 1740, 1670 (C=O), 1225 (COC).
1H NMR spectrum, δ, ppm: 0.95 t (3H, CH3CH2,
3JHH = 8 Hz), 1.42 m (4H, CH2), 1.52 s (4H, CH2),
1.72 m (2H, OCH2CH2), 2.48 m and 2.80 m (4H,
Ethyl 4-(3-morpholino-2,5-dioxo-2,3,4,5-tetra-
hydro-1H-pyrrol-1-yl)benzoate (Ve). Yield 44%,
RUSSIAN JOURNAL OF ORGANIC CHEMISTRY Vol. 43 No. 3 2007