TABLE 2. IR Spectra of Compound 4
2
C = O
ArCO
C = C
C = N
Experimental conditions
OH
COOCH
1760
3
free
in IMHB in IMHB in IHB
Vaseline oil
5% chloroform solution
1% chloroform solution
3395, 3150 (br)
3485, 3430
3485, 3430
1700
1717
1665
1620
1600
1600
1600
1725-1735 (br)
1745 (sh), 1730 1715, 1700 (sh) 1665(v.w.) 1625(w)
1665 (w) 1620 (w)
4
because the C=C, C=N stretching band is superimposed by the intense vibration band of the C C=O group involved in the
IHB, which is much stronger than the IMHB involving the same group.
A comparison of the spectra of the 5% and 1% solutions shows that in a dilute solution there are less associates
2
−1
due to the formation of IMHB involving C =O (the absorption band at 1665 cm vanishes), and the absorption bands of
−1
2
−1
the COOCH (1745 (sh), 1730 cm ) and C =O groups (1715, 1700(sh) cm ) are more distinctly resolved into two bands.
3
The latter may be due to the existence of two relatively stable conformers, where the bulky diphenylmethyleneamine
substituent is rotated around the N–N bond.
The PMR spectrum of pyrrolone 4 in DMSO-d is typical for this class of compounds: the C –OH signal lies in
the region of aromatic proton signals, and the C –OH signal is very broadened and is not observed at all. This is further
5
6
4
support to the fact that the intramolecular hydrogen bonds are strong in this compound.
EXPERIMENTAL
1
The IR spectra were recorded on a UR-20 instrument. The H NMR spectra were measured on an RYa-2310
(60 MHz, HMDC as internal standard) and Bruker AM-300 spectrometers. The UV spectra were taken on a Specord M40
spectrometer. The purity of the compounds was confirmed by TLC (Silufol UV-254 plates).
1-Diphenylmethyleneamino-5-methoxycarbonyl-4-p-toluoyl-2,3-dihydro-2,3-pyrroledione (2), 5-hydroxy-3-
methoxycarbonyl-4-p-toluoyl-1,6-dihydro-6-pyridazinone (3), and 3,5-dihydroxy-1-diphenylmethyleneamino-5-
methoxycarbonyl-4-p-toluoyl-2,5-dihydro-2-pyrrolone (4).
Oxalyl chloride (0.94 g, 0.011 mol) was dropped to a solution of methyl 2-diphenylmethylenehydrazino-4-oxo-
4-p-tolyl-2-butenic ether (4.00 g, 0.010 mol) in absolute benzene (30 ml). The mixture was boiled on a reflux condenser
for 2 h 15 min and cooled. Absolute hexane (15 ml) was added, and the precipitate of pyrroledione 2 was filtered off;
yield 1.35 g (30%), T = 145-146°C (from a 2:1 benzene–hexane mixture). Found, %: C 70.01, H 4.68, N 6.08. Calculated
dec
−1
2
3
for C H N O , %: C 71.67, H 4.46, N 6.19. IR spectrum (vaseline oil): v/cm : 1750 (C =O), 1730 (COOCH , C =O),
1630 (C C=O). H NMR spectrum (CDCl , 60 MHz, δ, ppm): 2.29, 3.80 (both s, 3H, CH , OCH ); 7.35 (m, 14H, Ar).
27 20
2
5
3
4
1
3
3
3
The mother solutions were consolidated, and the mixture was allowed to stay for 24 h for contact with air moisture.
The yellow precipitate of the hydrate form 4 was filtered off and recrystallized from a 3:1 chloroform–hexane mixture.
Yield 1.86 g (39%), T = 164-167°C (with decomp.). Found, %: C 69.08, H 4.56, N 6.04. Calculated for C H N O , %:
m
27 22 2 6
1
C 68.93, H 4.71, N 5.95. UV spectrum (MeCN), λ /nm (log ε): 256 (4.26), 405 (3.98). H NMR spectrum (DMSO-d ,
300 MHz, δ, ppm): 2.42, 3.87 (both s, 3H, CH , OCH ); 7.51 (m, 15H, Ar, C –OH).
max
6
5
3
3
The filtrate was evaporated, and the residue recrystallized from acetone. Yield of pyridazinone 3 is 0.10 g (3%),
T
= 269-270°C (with decomp.).
m
X-ray diffraction study of compound 4. The crystals C H N O are triclinic with cell dimensions a = 9.8540(10),
27 22
2 6
3
b = 10.0880(10), c = 13.982(2) Å, α = 69.820(10), β = 110.57(10), γ = 91.350(10)°, V = 1213.8(2) Å , M = 470.47, d
1.287 g/cm , Z = 2, space group P1. The data were collected on a KM-4 (KUMA DIFFRACTION) automatic four-circle
=
_
calc
3
diffractometer with χ-geometry (θ-2θ scan mode, monochromated CuK radiation, 3.6 < 2θ < 80.3°). The total number of
α
−1
data collected is 4510. No absorption correction was applied (µ = 0.760 mm ). The structure was solved by direct methods
with subsequent electron density syntheses.
The hydrogen atoms were objectively located on difference electron density maps. The full-matrix least-squares
refinement was carried out anisotropically (isotropically for hydrogens). In the final cycles the 3781 data with I ≥ 2σ(I)
852
Aliev
