1888 Sengupta et al.
Asian J. Chem.
analysis revealed three products formed: total conversion ~70%;
ratio 6a: 6b: 6c = 70:15:15. Chromatography over neutral
alumina furnished compounds 6a and 6c.
(CH), 1651 (amide CO), 1119 (O=C-N), 1090, 1015 & 498
(aryl Cl), 837 (1,4-disubstituted benzene ring), 763 & 698
(mono-substituted benzene ring). 1H NMR(300 MHz, CDCl3):
δ 4.22 (d, J = 9.0 Hz, H3), 3.38 (t, J = 9.0 Hz, H4), 5.47 (d, J
= 9.0 Hz, H5), 2.77 (s, N-CH3), 3.14 (s, CO-N-CH3), 7.25-
7.36 (overlapped signals of, A/H-2,6,3,5; B/H-2,6; C/H-3,5,4),
6.91 (t, J = 7.5 Hz, B/H-2,3), 7.20 (t, J = 7.5 Hz, B/C-4), 7.45
(d, J = 9.0 Hz, C/H-2,6); 13C NMR (75.5 MHz, CDCl3): δ 77.5
(C3), 63.4 (C4), 83.4 (C5), 44.1 (N-CH3),37.5 (CO-N-CH3), 168.5
(CO), 126.4, 127.0 (A/C-2,6; C/C-2,6), 127.7, 128.3 (B/C-4,
C/C-4), 128.6, 128.9, 129.0, 129.2 (A/ C-3,5; B/C-2, 6,3,5; C/
C-3,5), 135.1 (A/C-4), 139.3 (A/C-1), 141.5, 141.9 (B/C-1; C/
C-1). Elemental analysis calcd. (found) (%) of C24H23N2O2Cl:
C 70.8 (70.6); H 5.7 (5.6); 6.9 (6.7).
3,4-trans-4,5-trans-2-Methyl-3-(4′-chlorophenyl)-5-
phenyl-4-anilinyloxoisoxazolidine (6a): White microcrysta-
lline solid, m.p. 152-154 ºC, isolated yield 0.73g (42%) from
5% benzene in petroleum ether (60-80 ºC) eluates, Rf 0.46
(silica gel G, benzene). IR (KBr, νmax, cm-1): 3306 (NH), 3061,
2928, 2854 & 2367 (CH), 1658 (amide CO), 1091, 1021 &
506 (aryl Cl), 831 (1,4-disubstituted benzene ring), 745 & 693
(mono-substituted benzene ring). 1H NMR(300 MHz, CDCl3):
δ 4.18 (d, J = 9.0Hz, H3), 3.23 (dd, J = 9.0, 7.5 Hz, H4), 5.53 (d,
J = 7.5 Hz, H5), 2.78 (s, N-CH3), 8.05 (s, NH), 7.30-7.45
(overlapped signals of A/H-2,6,3,5; C/H-2,6,3,5), 7.10-7.30
(overlapped signals of, B/H-2,3,4,5,6), 7.50 (d, J = 7.1 Hz, H-
2,6). 13C NMR (75.5 MHz, CDCl3): δ 76.4 (C3), 69.7 (C4), 81.4
(C5), 43.8 (N-CH3), 167.2 (CO), 119.9 (B/C-2,6), 124.9 (B/C-
4), 126.0 (C/C-2,6), 128.8, 128.9, 129.0, 129.2 (A/C-2,6,3,5; B/
C-3,5; C/C-3,5), 129.1 (C/C-4), 134.2 (A/C-4), 137.0, 136.4 (A/
C-1; B/C-1), 141.2 (C/C-1). Elemental analysis calcd. (found)
(%) of C23H21N2O2Cl: C: 70.3 (70.1), H: 5.35 (5.2), N: 7.1 (6.9).
3,4-trans-4,5-trans-2-Methyl-3-(4′-chlorophenyl)-4-
phenyl-5-anilinyloxoisoxazolidine (6c): Yellow low-melting
solid, m.w. C23H21N2O2Cl, m.p. 39 ºC, isolated yield 0.12g (7%)
from 5% benzene in petroleum ether (60-80 ºC) eluates along
with the major compound 6a - after recrystallisation the major
compound separated out, the minor product 6c was obtained
from mother liquor. Rf 0.52 (silica gel G, benzene:EtOAc =
4:1). IR (KBr, νmax, cm-1): 3393 (NH), 2921& 2853 (CH), 1660
(amide CO), 1091 & 1016 & 500 (aryl Cl), 819 (1,4-disubstituted
benzene ring), 755 & 696 (mono-substituted benzene ring).
1H NMR(300 MHz, CDCl3): δ 4.58 (d, J = 5.0 Hz, H3), 3.85
(dd, J = 9.0, 5.0 Hz, H4), 3.54 (d, J = 9.0 Hz, H5), 2.67 (s, N-
CH3), 8.22 (s, -NH-), 7.14-7.31 (m, ovl., A/H-2,6,3,5; B/H-3,5),
7.45 (d, J = 7.6 Hz, B/H-2,6), 7.03-7.14 (overlapped signals
of, C/H-2,3,4,5,6). 13C NMR (75.5 MHz, CDCl3): δ 83.3 (C-
3), 81.9 (C-4), 63.2 (C-5), 170.5 (CO), 43.1(N-CH3), 137.3 (A/
C-1), 134.7 (A/C-4), 138.0 (B/C-1), 127.2 (B/C-2,6), 129.4 (B/
C-4), 134.7 (C/C-1), 120.8 (C/ C-2,6), 124.4 (C/ C-4), 128.9,
129.0, 129.2, 129.9 (B/C-3,5; C/C-3,5; A/C-2,6,3,5). Elemental
analysis calcd. (found) (%) of C23H21N2O2Cl: C: 70.3 (70.5),
H: 5.35 (5.5), N: 7.1 (6.9).
Detected by 1H-NMR in crude reaction mixture. 3,4-cis-
4,5-trans-2-Methyl-3-(4′-chlorophenyl)-5-phenyl-4-(N-
methylanilinyl)oxo isoxazolidine (7b): H-3 δ 4.64 (J = 7.5
Hz); H-4 δ 3.50 (dd, J = 9.0, 7.5Hz); H-5 δ 5.72 (J = 9.0 Hz).
X-Ray Diffraction analysis of compound 5c: Crystals
of compound 5c were obtained as elongated thin needles after
recrystallization from CHCl3 by slow evaporation at room tempe-
rature. They were mounted on a CCD NONIUS KAPPA system
operating the MoKα radiation (λ = 0.7107 Å). The LURE DC1
synchrotron facility in Orsay, France was used to record the data.
An Image Plate system (MAR 345) was used as the detector.
Recordings were done under cryotemperature conditions at
-50 ºC. The structures were solved by direct methods (SHELXS)
and refined using isotropic, then anisotropic thermal factors
(SHELXL program [19]. Hydrogens were gradually introduced
in the calculations and kept riding on the bonded atom during
all refinements. The final statistics of the refinements are shown
in Table-1, while Figs. 1-3 were drawn using the PLATON
program [20].
TABLE-1
XRD ANALYSIS OF 5c: PARAMETERS
AND REFINEMENT STATISTICS
CCDC reference No.
m.f.; m.w.
System; Space group
Cell parameters
604787
C23H20N2O2Cl2; 427.31
Monoclinic; P21/n
a=28.070(1) Å; b=5.5748(3)
Å; c=28.0597(1) Å
α=102.100 (3)°; α=γ=90°
8 / 4,293.4(4)
Mo Kα
Z / Volume (Å3)
Radiation
Nb. of measured Refl.
Detected by 1H NMR in crude reaction mixture. 3,4-cis-
4,5-trans-2-Methyl-3-(4′-chlorophenyl)-5-phenyl-4-anilinyl-
oxo isoxazolidine (6b): δ 3.92 (d, J = 8.9 Hz, H-3), 3.52 (dd,
J = 8.9, 5.4 Hz, H-4), 5.61 (d, J = 5.4 Hz, H-5).
Reaction of C-(4-chlorophenyl)-N-methyl nitrone (1)
(0.720 g, 0.0042 mol) with N-methylanilide of cinnamic acid
(4) (2.94 g, 3 × 0.0042 mol). Reaction time 26 h, 300 MHz 1H
NMR analysis revealed two products formed: total conversion
62%; ratio 7a:7b = 93:7. Chromatography over neutral alumina
furnished (7a).
18,452
2.10 - 20.85°
3250
2428
99 %
λ
min – λmax
Nb. of independent refl.
Nb. of obs. refl. (F ≥ 4σ(I))
completeness
Final R (obs. F)
0.1002
Final R (all data)
0.0943
0.2290
0.1912
Final Rw (obs. F2)
Final Rw (all F2 data)
Residual in last e-map (min-max) e- -0.30/+0.38
3,4-trans-4,5-trans-2-Methyl-3-(4′-chlorophenyl)-5-
phenyl-4-(N-methylanilinyl)oxoisoxazolidine (7a): Yellow
amorphous solid from hexane eluates after preparative TLC,
Rf 0.49 (silica gel G, benzene: ethyl acetate= 4:1), (isolated
yield 0.84 g, 50%). IR (KBr, νmax, cm-1): 3057, 3030 & 2880
The crystallographic parameters and refinement statistics
of compound 5c are given in Table-1. The numberings of struc-
tures as given in these projections are those provided in the X-
ray crystallographic analysis outputs.