PETROV et al.
1692
what darker to the end of the process. On cooling the
reaction mixture to 2025°C the excess thionyl chloride
was distilled off in a vacuum. To the residue 30 ml of cold
water was added to decompose the traces of thionyl chlo-
ride. The separated precipitate was filtered off, washed
with water (5´20 ml), and dried. Yield of the crude reac-
tion product 1.8 g. It was extracted with boiling benzene
(3´15 ml), the substance precipitated from the extract
was filtered off, washed with a little benzene, and dried.
Yield of compound IV 0.7 g (52%). Light-yellow small
crystals, mp 270°C (decomp), Rf 0.54 (eluent chloroform
(6.6 mmol) of 1-(5-acetyl-2,4-dihydroxyphenyl)-1-
ethanone (I) [13], 1.37 g (13.16 mmol) of ethoxy-
carbonylhydrazine, and 20 ml of toluene was boiled for
2 h while distilling off water into the Dean-Stark trap.
The reagents first dissolved giving a light-yellow solution,
and in 30 min a colorless precipitate of ethoxycarbonyl-
hydrazone separated. On completion of the reaction the
precipitate was filtered off, thoroughly washed with wa-
ter, and dried. Yield of ethoxycarbonylhydrazone II 1.76
g (95%). Fine crystalline powder, mp. 245247°C, Rf 0.44
(eluent chloroform-acetone, 5:1).
1H NMR spectrum (DMSO-d6), d, ppm: 1.26 t
(CH3CH2), 2.35 s (CH3C=N), 2.62 s (CH3C=O), 4.2 q
(CH2CH3), 6.32 s (H6 ), 7.99 s ( H3 ), 10.72 s ( OH1),
12.56 s (NH), 14.03 s (OH5). 13C NMR spectrum
(DMSO-d6), d, ppm: 13.7 (CH3CH2), 14.8 (CH3C=N),
27.19 ( CH3C=O), 61.59 (CH2CH3), 104 (C6), 112.2 (C2),
113.24 (C4), 132.93 (C3), 154.38 (C=N), 164.23 (C1),
165.79 (C5), 203.1 (C=O). Mass spectrum, m/z (Irel, %):
M+ 280 (100). Found, %: C 55.87, 55.64; H 5.82, 5.93.
C13H16N2O5. Calculated, %: C 55.71; H 5.75.
1
acetone,5:1). H NMR spectrum (DMSO-d6), d, ppm:
6.83 s (H2), 9.27 s (H5), 9.33 s (H, Ht), 10.81 s (OH).
13C NMR spectrum (DMSO-d6), d, ppm: 103.43 (C4, C6),
110.13 (C2), 130.23 (C5, Ht), 132.83 (C4, Ht), 156.37 (C5),
158.07 (C1, C3). Mass spectrum, m/z (Irel, %): M+ 278
(95). Found, %: C 42.97, 43.21; H 2.24, 2.33.
C10H6N4O2S2. Calculated, %: C 43.16; H 2.16.
2,6-Di(butylthio)furo[3',2':4,5]benzo[b]-furan
(VI). A dispersion of 0.46 g (1.66 mmol) of compound
IV, 0.69 g (4.98 mmol) of freshly calcined potassium car-
bonate, 0.46 g (3.32 mmol) of butyl bromide, and 50 ml of
dry acetonitrile was boiled for 2 h at vigorous stirring.
Then the reaction mixture was filtered, and the filtrate
was evaporated in a vacuum. The residue was subjected
to chromatography on a column (3´10 cm) packed with
silica gel of the grade L 100/160, eluent carbon tetrachlo-
ride. From the first fraction on removal of the solvent we
obtained 0.23 g (42%) of viscous light-yellow oily com-
1-(5-Acetyl-2,4-dihydroxyphenyl)-1-ethanone
bis(ethoxycarbonylhydrazone) (III). A mixture of
2.8 g 10 mmol) of compound II, 5.2 g (50 mmol) of
ethoxycarbonylhydrazine, 1 ml of acetic acid, and 200 ml
of ethanol was boiled at vigorous stirring for 30 h. On
completion of the reaction the light-greenish precipitate
was filtered off, washed with ethanol (5´20 ml), and
dried. Yield of bis(ethoxycarbonylhydrazone) (III)
3.26 g (89%). Fine crystalline greenish powder, mp 275°C
1
pound VI, Rf 0.63 (eluent carbon tetrachloride). H NMR
spectrum (CDCl3), d, ppm: 0.91 t (CH3), 1.46 t. d
(SCH2CH2), 1.65 t.d (SCH2CH2CH2), 2.94 t.t (SCH2),
6.81 s (H3, H5), 7.47 s (H8), 7.51 s (H4). 13C NMR spec-
trum (CDCl3), d, ppm: 13.35 (CH3), 21.39 (CH2CH3),
31.57 (SCH2), 34.23 (SCH2CH2), 93.67 (C8), 109.48 (C4),
110.61 (C3, C5), 125.19 (C3a, C4a), 150.6 (C7a, C8a), 154.36
(C2, C6). Mass spectrum, m/z (Irel, %): M+ 334 (27).
Found, %: C 64.49, 64.67; H 6.45, 6.59. C18H22O2S2.
Calculated, %: C 64.41, H 6.54.
1
(decomp.), Rf 0.36 (eluent chloroformacetone, 3:1). H
NMR spectrum (DMSO-d6), d, ppm: 1.26 t (CH3CH2),
2.32 C (CH3C=N), 4.19 q (CH2CH3), 6.28 s (H6), 7.59 s
( H3 ), 10.63 s (NH), 13.38 s (OH). 13C NMR spectrum
(DMSO-d6), d, ppm: 13.75 (CH3CH2), 14.83 (CH3C=N),
61.43 (CH2CH3), 104.52 (C6), 112.2 (C2 and C4), 128.68
(C3), 154.42 (C=N and C=O), 161.31 (C1 and C5). Mass
spectrum, m/z (Irel, %): M+ 366 (80). Found, %: C 52.36,
52.545; H 5.91, 5.79. C16H22N4O6. Calculated, %: C 52.45;
H 6.05.
2,6-Di(benzylthio)furo[3',2':4,5]benzo-[b]furan
(VII). Adispersion of 0.09 g (0.324 mmol) of 4,6-di(1,2,3-
thiadiazol-4-yl)-1,3-phenylenediol (IV), 0.134 g (0.971
mmol) of freshly calcined potassium carbonate, 0.082 g
(0.647 mmol) of benzyl chloride, and 5 ml of dry acetoni-
trile was boiled for 2 h at vigorous stirring. Then the re-
action mixture was filtered, and the filtrate was evapo-
rated in a vacuum. The residue was subjected to chro-
matography on a column (3´10 cm) packed with silica
gel of the grade L 100/160, eluent carbon tetrachloride.
From the first fraction on removal of the solvent we ob-
4,6-Di(1,2,3-thiadiazol-4-yl)-1,3-phenylenediol
(IV). In a flask equipped with a magnetic stirrer, a reflux
condenser, and a system for removal and absorption of
gases was added to 1.76 g (4.81 mmol) of 1-(5-acetyl-
2,4-dihydroxyphenyl)-1-ethanone bis(ethoxycarbonylhy-
drazone) (III) 30 ml of freshly distilled thionyl chloride.
The mixture was heated at reflux and stirring for 5 h; the
mixture became homogeneous about 5 min after the start
of reaction turning into a brown solution that got some-
RUSSIAN JOURNALOF ORGANIC CHEMISTRY Vol. 40 No. 11 2004