STUDY OF LIQUID-PHASE DEHYDRATION
1313
heated in the apparatus for distillation to 250–255ºC at
a residual pressure of 100–80 mm Hg. The distillate
was collected over 1.5 h at gradual lowering the
pressure to 30 mm Hg at the end of the reaction. 4.10 g
of distillate was obtained which was subjected to
steam-distillation, the products were extracted with
diethyl ether, the extract was dried for 5 minutes over
KOH, then ether was removed in a vacuum on a rotary
evaporator. Yield of a mixture of IV and V was 0.48 g.
5.476, 5.479, 5.520, 5.523 d.d (trans-H, J 17.6 Hz),
6.552, 6.580, 6.596, 6.624 m (vic-H), 6.642, 6.647,
6.659, 6.664 (2H, 2,6-Ar), 7.181, 7.185, 7.197, 7.202
(2H, 3, 5-Ar).
c. Finely ground mixture of 10.85 g (0.0791 mol) of
d,l-1-(4-aminophenyl)ethanol, 0.0543 g (0.5 wt.%) of
hydroquinone, and 0.211 g (2.0 wt.%) of H3 BO3 was
heated to 245ºC at a pressure of 80 mm Hg. The
mixture began to boil, and along with the increase in
the bath temperature to 255ºC a small amount of
distillate was obtained. The product was isolated and
purified as described above. Yield: 0.05 g, colored
1
Transparent liquid, easily oxidized in air. H NMR
spectrum, δ, ppm: 1.110, 1.129, 1.148 t (3H, CH3),
2.434, 2.453, 2.472, 2.491 q (2H, CH2), 4.873 s (2H,
NH2, V), 4.898, 4.901, 4.925, 4.929 d.d (cis-H, J 10.9
Hz), 5.310 s (2H, NH2, IV), 5.481, 5.485, 5.525, 5.529
d.d (trans-H, J 17.6 Hz), 6.558, 6.585 (vic-H), 6.611,
6.616, 6.627, 6.632 d (2H, 2,6-Ar, V), 6.652, 6.657,
6.669, 6.673 d (2H, 2,6-Ar, J 8.5 Hz, IV), 6.889,
6.894, 6.905, 6.910 d (2H, 3,5-Ar, V), 7.184, 7.189,
7.201, 7.206 d (2H, 3,5-Ar, J 8.4 Hz, IV).
1
liquid. According to the H NMR spectroscopy, a
substance consisted mostly of 4-aminostyrene contain-
ing admixture of 1-amino-4-ethylbenzene.
d. A mixture of 8.33 g (0.06 mol) of d,l-1-(4-
aminophenyl)ethanol, 0.05 g (0.6 wt %) of hydro-
quinone, 0.167 g of KHSO4 (2.0 wt.%), and 0.150 g of
KH2PO4 (1.8 wt.%) was treated as described in the
method b. Yield 0.05 g (0.7%) of 4-aminostyrene.
b. To a mixture of 9.8 g (0.0714 mol) of d,l-1-(4-
aminophenyl)ethanol, 0.10 g (1.02 wt %) of KHSO4
and 0.10 g (1.02 wt %) of hydroquinone heated to 65–
70°C was added 0.025 g (0.255 wt %) of H3BO3, the
reaction mixture was heated to 255°C, then the
pressure in the system was lowered to 100 mm Hg and
after 10 min to 30 mm Hg, and then the distillation
started. The distillate weight was 4.96 g. The residue
was subjected to steam-distillation, the distillates were
combined and again subjected to steam-distillation.
Then 4-aminostyrene was extracted with diethyl ether,
the extract was dried for 5 minutes over KOH, the
solution was decanted from drying agent, and the
solvent was removed in a vacuum on a rotary
evaporator. Yield: 0.15 g (1.8%), clear liquid coloriz-
REFERENCES
1. Kolesnikov, G.C., Sintez vinil’nykh proizvodbykh
aromaticheskikh i geterotsiklicheskikh soedinenii (Syn-
thesis of Vinyl Derivatives of Aromatic and Hetero-
cyclic Compounds), Moscow: Akad. Nauk SSSR, 1960.
2. Gauthier, D. and Gauthier, P., Bull. Soc. Chim., 1933,
vol. 53, p. 323.
3. Mowry, D.T., Renoll, M., and Huber, W.F., J. Am.
Chem. Soc., 1946, vol. 68, p. 1105.
4. Manecke, G. and Rotter, U., Makromol. Chem., 1969,
vol. 127, p. 264.
5. Agronomov, A.E. and Shabarov, Y.S., Laboratornye
raboty v organicheskom practikume (Laboratory Work
in Organic Workshop), Moscow: Khimiya, 1974, p. 191.
1
ing in air. H NMR spectrum, δ, ppm: 4.890, 4.894,
4.918, 4.921 d.d (cis-H, J 10.9 Hz), 5.323 s (2H, NH2),
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 80 No. 7 2010