Synthesis of 2-R-6-R-4-(5-amino-1,3,4-oxadiazol-2-yl)quinolines

Full text of DOI:10.1134/S1070428009110311

ISSN 1070-4280, Russian Journal of Organic Chemistry, 2009, Vol. 45, No. 11, pp. 1734–1735. © Pleiades Publishing, Ltd., 2009.
Original Russian Text © A.G. Kashaev, A.V. Zimichev, 2009, published in Zhurnal Organicheskoi Khimii, 2009, Vol. 45, No. 11, p. 1738.
SHORT
COMMUNICATIONS
Synthesis
of 2-R-6-R'-4-(5-Amino-1,3,4-oxadiazol-2-yl)quinolines
A.G. Kashaev andA.V. Zimichev
Samara State Technical University, Samara, 443100 Russia
e-mail: fpp@samgtu.ru
Received March 13, 2009
DOI: 10.1134/S1070428009110311
Compounds containing in the structure a fragment of
2-R-1,3,4-oxadiazol exhibit a high tuberculocidal activity
toward M. tuberculosis H37Rv [1]. In order to extend
the amount of compounds with a potential biological
activity we prepared 2-R'-6-R-4-(5-amino-1,3,4-oxadi-
azol-2-yl)quinolines by the cyclization of the correspond-
ing 2-R'-6-R quinoline-4-carbohydrazides with cyanogen
bromide in anhydrous ethanol.
4-(5-Amino-1,3,4-oxadiazol-2-yl)-2-methylquino-
line (I).Amixture of 1 g (5 mmol) of 2-methylquinoline-
4-carbohydrazide, 0.503 g (5 mmol) of cyanogen bromide,
and 20 ml of anhydrous ethanol was heated for 12 h. On
cooling the solvent was distilled off in a vacuum, the
residue was treated with a water solution of NH4OH,
the precipitate was filtered off and recrystallized from
ethanol. Yield 0.98 g (87%), yellow crystals, mp 271–
272°C (EtOH). 1H NMR spectrum, δ, ppm: 2.87 s (3H,
CH3), 7.83 s (2H, NH2). Found, %: C 63.67; H 4.44;
N 24.74. C12H10N4O. Calculated, %: C 63.70; H 4.46;
N 24.77.
Compounds II–VI were obtained similarly.
4-(5-Amino-1,3,4-oxadiazol-2-yl)-2-phenylquino-
line (II). Yield 1.24 g (86%), yellow crystals, mp 232–
1
234°C (EtOH). H NMR spectrum, δ, ppm: 7.60–8.57
(5H, 5CHphenyl), 7.85 s (2H, NH2). Found, %: C 70.78;
H 4.18; N 19.39. C17H12N4O. Calculated, %: C 70.82;
H 4.20; N 19.43.
4-(5-Amino-1,3,4-oxadiazol-2-yl)-2,6-dimethyl-
quinoline (III). Yield 1.16 g (97%), yellow crystals, mp
224–226°C (EtOH). 1H NMR spectrum, δ, ppm: 2.52 s
(3H, C6H3 ), 2.67 (3H, C2H3 ), 7.64 s (2H, NH2). Found,
%: C 64.98; H 4.49; N 23.30. C13H12N4O. Calculated,
%: C 64.99; H 5.03; N 23.32.
4-(5-Amino-1,3,4-oxadiazol-2-yl)-6-methyl-2-
phenylquinoline (IV). Yield 1.34 g (88%), yellow
crystals, mp 231–232°C (EtOH). 1H NMR spectrum,
δ, ppm: 2.52 s (3H, CH3), 7.51–8.23 m (5H,
5CHphenyl), 7.58 s (2H, NH2). Found, %: C 71.48;
H 4.57; N 18.53. C18H14N4O. Calculated, %: C 71.51;
H 4.61; N 18.53.
4-(5-Amino-1,3,4-oxadiazol-2-yl)-2-methyl-6-
methoxyquinoline (V). Yield 0.97 g (76%), yellow
crystals, mp 226–227°C (EtOH). 1H NMR spectrum, δ,
ppm: 2.48 (3H, CH3) 2.66 s (3H, OCH3), 7.53 s (2H,
NH2). Found, %: C 67.91; H 4.42; N 17.58. C18H14N4O2.
Calculated, %: C 67.92; H 4.43; N 17.60.
NH2
N
O
O
N
N
NH2
BrCN
R
R
N
R'
N
R'
I_VI
I, R = H, R' = CH3; II, R = H, R' = Ph; III, R = CH3, R' = CH3;
IV, R = CH3, R' = Ph; V, R = OCH3, R' = CH3; VI, R = H, R' =
2-thienyl.
4-(5-Amino-1,3,4-oxadiazol-2-yl)-2-(2-
thienyl)quinoline (VI). Yield 1.23 g (84%), yellow
crystals, mp 218–220°C (EtOH). H NMR spectrum, δ,
1
1734

SYNTHESIS OF 2-R-6-R'-4-(5-AMINO-1,3,4-OXADIAZOL-2-YL)QUINOLINES
1735
ppm: 7.24 t (1H, C4thienyl, J 4.03 Hz), 7.75 d (1H, C3thienyl
,
reference TMS. Elemental analysis was performed on
an analyzer Euro Vector EA 3000.
J 5.13 Hz), 7.82 d (1H, C5thienyl, J 5.14 Hz), 8.07 s(2H,
NH2). Found, %: C 61.17; H 3.39; N 19.02; S 10.87.
C15H10N4OS. Calculated, %: C 61.21; H 3.42; N 19.04;
S 10.89.
REFERENCES
1H NMR spectra were registered on a spectrometer
Bruker AC-300 (300 MHz) in DMSO-d6, internal
1. Makaev, F.Z., Doctoral Sci. (Chem.) Dissertation, Kishinev,
2006, 91 p.
RUSSIAN JOURNAL OF ORGANIC CHEMISTRYVol. 45 No. 11 2009