2-(FUR-2-YL)NAPHTHO[2,1-d]OXAZOLE
97
Table 2. Parameters of the IR and 1H NMR spectra of obtained compounds
Comp.
no.
IR spectrum,
1Н NMR spectrum, δ, ppm (J, Hz, СDCl3)
ν, cm–1
–
6.62–6.64 m (1Н, Н4'), 7.31 d (1Н, Н3', J 3.6), 7.52 t (1Н, Н7, arom., J 8.2), 7.63 t (1Н, Н8, arom., J 7.8),
7.67 d (1Н, Н5', J 1.5), 7.78 d (1Н, Н5, arom., J 8.7), 7.82 d (1Н, Н4, arom., J 8.7), 7.96 d (1Н, Н6, arom.,
J 8.4), 8.27 d (1Н, Н9, arom., J 8.1)
I
1370 s
1550 as
7.45 d (1Н, Н3', J 3.9), 7.48 d (1Н, Н4', J 3.9), 7.62 t (1Н, Н7, arom., J 8.1), 7.67 t (1Н, Н8, arom., J 8.1),
7.80 d (1Н, Н5, arom., J 8.7), 7.84 d (1Н, Н4, arom., J 8.7), 7.96 d (1Н, Н6, arom., J 8.4), 8.29 d (1Н, Н9,
arom., J 8.1)
IIIа
IIIb
IIIc
IIId
IIIe
–
6.56 d (1Н, Н4', J 3.6), 7.24 d (1Н, Н3', J 3.6), 7.53 t (1Н, Н7, arom., J 8.1), 7.63 t (1Н, Н8, arom., J 8.1),
7.78 d (1Н, Н5, arom., J 8.7), 7.81 d (1Н, Н4, arom., J 8.7), 7.96 d (1Н, Н6, arom., J 8.4), 8.27 d (1Н, Н9,
arom., J 8.1)
1680
(С=О)
7.41 d (1Н, Н3', J 3.6), 7.43 d (1Н, Н4', J 3.6), 7.57 t (1Н, Н7, arom., J 8.1), 7.67 d (1Н, Н8, arom., J 8.1),
7.83 d (1Н, Н5, arom., J 8.7), 7.84 d (1Н, Н4, arom., J 8.7), 7.98 d (1Н, Н6, arom., J 8.4), 8.32 d (1Н, Н9,
arom., J 8.1), 9.86 s (1Н, СНО)
1670
(С=О)
2.64 s (3Н, СН3), 7.34 d (1Н, Н3', J 3.6), 7.38 t (1Н, Н4', J 3.6), 7.57 t (1Н, Н7, arom., J 8.1), 7.66 t (1Н, Н8,
arom., J 8.1), 7.83 d (1Н, Н5, arom., J 8.7), 7.84 d (1Н, Н4, arom., J 8.7), 7.98 d (1Н, Н6, arom., J 8.4),
8.32 d (1Н, Н9, arom., J 8.1)
–
7.37 d (1Н, Н3', J 3.5), 7.40 d (1Н, Н4', J 3.5), 7.54 t (3Н, Н3,4,5, arom., J 7.7), 7.58 t (1Н, Н7, arom., J 8.1),
7.68 t (1Н, Н8, arom., J 8.1), 7.83 d (1Н, Н5, arom., J 8.6), 7.85 d (1Н, Н4, arom., J 8.6), 7.98 d (1Н, Н6,
arom., J 8.3), 8.12 d (2Н, Н2,6, arom., J 7.8), 8.32 d (1Н, Н9, arom., J 8.1)
EXPERIMENTAL
2-(5-Formylfur-2-yl)naphtho [2,1-d]oxazole (IIIc).
To a mixture of 1.18 g of compound I and 20 g of
polyphosphoric acid 2.8 g of hexamethylenetetramine
was added, and the resulting mixture was heated at 80–
90°C with intense stirring for 5 h. After that the
reaction mixture was diluted with 50 ml of water and
neutralized with ammonia. The reaction product was
extracted with methylene chloride and chromato-
graphed on a column filled with aluminum oxide.
After that the solvent was removed and the residue was
crystallized from ethanol.
1H NMR spectra were taken on a Varian Unity 300
spectrometer (300 MHz) in CDCl3, internal reference
TMS. Elemental analysis was carried out on a Perkin
Elmer 2400 analyzer. Melting points were measured in
capillary on a PTP device. Yields and properties of
compounds are listed in tables 1 and 2.
2-(Fur-2-yl)naphtha[2,1-d]oxazole (I). To a solu-
tion of 1.59 g of 1-hydroxy-2-aminonaphthalene in
10 ml of 1-methyl-2-pyrrolidone 1.31 g of furoyl chlo-
ride was added. Reaction mixture was boiled for 2 h,
cooled and poured in 50 ml of cold water. The ob-
tained precipitate was filtered off, thoroughly washed
with cold water, and crystallized from ethanol.
2-(5-Acetylfur-2-yl)naphtho[2,1-d]oxazole (IIId).
To a solution of 1.18 g of compound I in 15 ml of
acetic anhydride the catalytic amount of magnesium
perchlorate (0.005 g) was added, and the resulting
mixture was boiled for 1.5 h. After that the reaction
mixture was decomposed with 25 ml of water and
neutralized with concentrated ammonia. The reaction
product was extracted with methylene chloride and
chromatographed on a column packed with Al2O3,
elution with methylene chloride. The solvent was
evaporated, and the residue was crystallized from
ethanol.
2-(5-Nitrofur-2-yl)naphtho[2,1-d]oxazole (IIIa).
A solution of 1.18 g of compound I in 25 ml of nitric
acid (d 1.35) was boiled for 2 h. The reaction mixture
was cooled and poured in 100 ml of cold water. The
obtained precipitate was filtered off, washed 2-3 times
with small amounts of cold water, and crystallized
from ethanol.
2-(5-Bromofur-2-yl)naphtho[2,1-d]oxazole (IIIb).
To a solution of 1.18 g of compound I in 25 ml of
dichloroethane 1.6 g of bromine was added, and the
resulting mixture was refluxed for 4 h. After that it was
evaporated in air, the residue was dissolved in me-
thylene chloride and chromatographed on a 15×2.5 cm
column fllled with Al2O3, elution with methylene
chloride. The product was crystallized from ethanol.
2-(5-Benzoylfur-2-yl)naphtho[2,1-d]oxazole (IIIe).
A mixture of 1.18 g of compound I, 20 g of poly-
phosphoric acid, and 1.8 g of benzoic acid was heated
with stirring at 150–160°C for 15 h. The reaction
product was isolated analogously to the acetyl
derivative Id and crystallized from 2-propanol.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 83 No. 1 2013