TAUTOMERISM AND STEREODYNAMICS OF INDOPHENOLS, AMIDINES
779
(CDCl3), , ppm: 1.17 s (9H), 1.21 s (9H), 3.88 s
(1H), 4.39 d (1H), 5.28 m (2H), 5.57 m (1H), 6.31 d
(1H), 6.47 d (1H), 6.58 d (1H), 6.67 s (1H), 6.70 d
(1H).
Ethyl 2-(3,5-di-tert-butyl-4-oxo-2,5-cyclohexa-
dienylidenamino)-4-nitrophenoxyacetate (XVII).
1
mp 120 C. Yield 60%. H NMR spectrum (CDCl3),
, ppm: 1.17 s (9H), 1.25 s (9H), 1.31 t (3H), 4.22 q
(2H), 4.72 s (2H), 6.61 d (1H), 6.85 d (1H), 7.06 d
(1H), 7.69 d (1H), 8.05, d. d (1H).
3 ,5 -Di-tert-butyl-7-chloro-2-phenyl-2,3-dihydro-
1,4-benzoxazine-3-spiro-1 -cyclohexa-2 ,5 -dien-4 -
1
one (VII). mp 223 C. Yield 80%. H NMR spectrum
Ethyl 2-(3,5-di-tert-butyl-4-oxo-2,5-cyclohexa-
(CDCl3), , ppm: 1.07 s (9H), 1.08 s (9H), 4.07 s
(1H), 5.02 m (1H), 6.42 d (1H), 6.61 d (1H), 6.69 d
(1H), 6.73 d (1H), 6.87 d (1H), 7.20 m (5H).
dienylidenamino)-5-nitrophenoxyacetate (XVIII).
1
mp 118 C. Yield 55%. H NMR spectrum (CDCl3),
, ppm: 1.16 s (9H), 1.25 m (3H), 1.30 s (9H), 4.22 q
(2H), 4.52 s (2H), 6.54 d (1H), 6.86 d (1H), 7.05 d
(1H), 7.68 d (1H), 7.93 d.d (1H).
7-Bromo-3 ,5 -di-tert-butyl-2-vinyl-2,3-dihydro-
1,4-benzoxazine-3-spiro-1 -cyclohexa-2 ,5 -dien-4 -
1
one (VIII). mp 175 C. Yield 65%. H NMR spectrum
Diethyl 3 ,5 -di-tert-butyl-4 -oxo-2,3-dihydro-
1,4-benzoxazine-3-spiro-1 -cyclohexa-2 ,5 -diene-2,2-
dicarboxylate (XIX). To a solution of 0.31 g of
compound XII in 10 ml of acetone we added 0.5 g
of potassium carbonate and 0.34 g of diethyl bromo-
malonate [4], and the mixture was left overnight at
room temperature. It was then filtered, the filtrate
was evaporated, and the residue was purified by
column chromatography on Al2O3 (eluent chloroform),
followed by recrystallization from 2-propanol.
(CDCl3), , ppm: 1.17 s (9H), 1.21 s (9H), 3.93 s
(1H), 4.37 d (1H), 5.29 m (2H), 5.54 m (1H), 6.33 d
(1H), 6.49 d (1H), 6.78 m (3H).
7-Bromo-3 ,5 -di-tert-butyl-2-phenyl-2,3-dihydro-
1,4-benzoxazine-3-spiro-1 -cyclohexa-2 ,5 -dien-4 -
1
one (IX). mp 228 C. Yield 75%. H NMR spectrum
(CDCl3), , ppm: 1.07 s (9H), 1.09 s (9H), 4.01 s
(1H), 5.00 s (1H), 6.38 d (1H), 6.59 d (1H), 6.82 m
(3H), 7.19 m (5H).
1
mp 95 C. Yield 75%. H NMR spectrum (CDCl3),
2,4-Di-tert-butyl-7-nitrophenoxazin-3-one (XI).
1
, ppm: 1.08 m (6H), 1.39 s (18H), 4.08 4.17 m
(4H), 5.18 s (1H), 6.52 d.d (1H), 6.72 6.85 m (3H),
7.29 s (2H).
mp 95 C. Yield 25%. H NMR spectrum (CDCl3), ,
ppm: 1.33 s (9H), 1.49 s (9H), 7.11 s (1H), 7.76 d
(1H), 8.07 d.d (1H), 8.11 d. Mass spectrum: m/z 354
(M+).
ACKNOWLEDGMENTS
2-Benzoyl-3 ,5 -di-tert-butyl-2,3-dihydro-1,4-
benzoxazine-3-spiro-1 -cyclohexa-2 ,5 -dien-4 -one
(XV). To a solution of 0.14 g of compound XII in
10 ml of acetone we added 0.3 g of potassium carbo-
nate and 0.07 g of phenacyl bromide. The mixture
was refluxed for 1 2 min and was kept for 7 8 h at
room temperature. The solution was filtered, the fil-
trate was evaporated, and the residue was purified
by column chromatography on Al2O3 (eluent chloro-
form), followed by recrystallization from 2-propanol.
This study was financially supported by the Rus-
sian Foundation for Basic Research (project no. 98-
03-32903a) and by the Program Universities of
Russia Basic Research (project no. 5.3.1387).
REFERENCES
1. Olekhnovich, R.Ya., Korobov, M.S., Lyubchenko, S.N.,
Sukholenko, E.S., Nivorozhkin, L.E., Olekhnovich, L.P.,
and Minkin, V.I., Zh. Obshch. Khim., 1992, vol. 62,
no. 4, p. 901.
1
mp 179 C. Yield 45%. H NMR spectrum (CDCl3),
, ppm: 1.35 s (18H), 5.02 s (1H), 6.56 s (1H), 6.7
6.9 m (4H), 6.98 s (2H), 7.44 m (2H), 7.56 m (1H),
8.02 d (2H).
2. Olekhnovich, L.P., Simakov, V.I., Furmanova, N.G.,
Ivakhnenko, E.P., Rekhlova, O.Yu., Ryskina, T.A., and
Zhdanov, Yu.A., Zh. Obshch. Khim., 1992, vol. 62,
no. 4, pp. 885 900.
2-p-Bromobenzoyl-3 ,5 -di-tert-butyl-2,3-dihy-
dro-1,4-benzoxazine-3-spiro-1 -cyclohexa-2 ,5 -dien-
4 -one (XVI) was synthesized as described above for
compound XV by reaction of compound XII with
3. Olekhnovich, L.P., Ivakhnenko, E.P., Simakov, V.I.,
Lyubchenko, S.N., Ryskina, T.A., Zakharchenko, S.G.,
and Kogan, V.A., Zh. Obshch. Khim., 1990, vol. 60,
no. 7, pp. 1609 1617.
1
p-bromophenacyl bromide. mp 180 C. Yield 35%. H
NMR spectrum (CDCl3), , ppm: 1.36 s (18H), 5.07 s
(1H), 6.46 s (1H), 6.81 m (3H), 6.95 s (2H), 7.58 m
(3H), 7.88 d (2H).
4. Lieb, H. and Schoniger, W., Anleitung zur Darstellung
organischer Praparate mit kleinen Substanzmengen,
Wien: Springer, 1950. Translated under the title Sintez
organicheskikh preparatov iz malykh kolichestv
veshchestv, Leningrad: GNTIKhL, 1957, pp. 67 68.
Compounds XVII and XVIII were synthesized as
described above for compound III using ethyl bromo-
acetate as alkylating agent.
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 71 No. 5 2001