5
44
TSIRUL’NIKOVA et al.
The hydrolysis of the corresponding nitriles is used
at cooling to 5–10°С. The precipitate of acid I was
filtered off after 15–20 h and washed with distilled
water to chloride ion disappearance. Yield 48%, mp
218–222°С with decomposition (mp 218–222°С with
to obtain acid II as well as other similar acids of the
secondary amines series [3]. The main disadvantages
of this process consist in the use of highly toxic
acrylonitriles, poor processability and laboriousness
1
3
decomp. [3]). The product was identified by the
NMR spectroscopy data.
С
(
many stages, manifold use of energy-consuming
procedures of distillation). The pure product II in this
case was obtained in a low yield by multiple re-
crystallization of technical acid II.
Ethylene diamine-N,N'-dipropionic acid (II).
Into a four-neck flask were charged under stirring
1
00 ml of water and 1.5 mol of β-chloropropionic acid,
We found conditions for direct carboxyalkylation
of ethylene diamine with calcium β-chloropropionate
in the presence of calcium oxide to keep the pH of the
reaction mixture at 9.0–11.0 at 75–85°С. Further
decomposition of the formed calcium complex of the
acid II by hydrochloric acid gives rise to acid II
released as dihydrochloride [4].
which was neutralized with calcium oxide to рН 9.0–
1
0
1.0. To the obtained suspension was added dropwise
.7 mol of ethylene diamine maintaining the
temperature of the reaction mixture at 80–85°С and рН
at 9.0–11.0 by adding calcium oxide. When all amine
was added, the reaction mixture was kept for 1.0–1.5 h
at the same temperature and рН, cooled to 50–55°С,
and mixed with concentrated hydrochloric acid at 70–
Ethylene diamine-N,N,N',N' -tetrapropionic acid
I). A four-neck flask equipped with mechanical stirrer,
7
5°С to decompose the calcium complex. Then the
(
obtained solution was cooled to 10–15°С, and after
reflux condenser and dropping funnels was charged
under stirring with 100 ml of water, 2.14 mol of β-
chloropropionic acid and placed into a bath with
heating and cooling. The acid was neutralized with
2
0 h the acid II dihydrochloride precipitate was
filtered off. The latter was washed with ethanol and
dried. Yield 40%. The target product structure was
1
3
confirmed with С NMR spectra data.
4
0% NaOH aqueous solution to рН 9.0–11.0. This
mixture was heated to 40–45°С. Then 1 mol of
ethylene diamine and 40% NaOH solution were slowly
added dropwise for maintaining pH 9.0–11.0 with such
rate that the temperature of the reaction mixture would
not exceed 85°С. When all amine was charged and pH
value became invariable in time, the reaction mixture
was stirred at 80–85°С for 1.0–1.5 h, then it was
cooled to room temperature and filtered from sodium
chloride. The filtrate was cooled to 10–15°С and
acidified with hydrochloric acid to рН 1.5–2.0. After
REFERENCES
1
.
Dyatlova, N.M., Temkina, V.Ya., and Kolpakova, I.D.,
Kompleksony Complexones, Moscow: Khimiya, 1970,
p. 107.
Tsirul’nikova, N.V. and Chicherina, G.P., RF Patent
no. 2308448, 2007, Byull. Izobret., no. 29.
2
3
.
.
Martell, A.E. and Chaberek, S., J. Am. Chem. Soc.,
950, vol. 72, p. 5357.
1
1
5–20 h dihydrochloride I was filtered off, dissolved
4. Tsirul’nikova, N.V. and Tarasova, М.А., RF Patent
no. 2307828, 2007, Byull. Izobret., no. 28.
in water and treated with triethylamine to рН 4.0–4.5
RUSSIAN JOURNAL OF GENERAL CHEMISTRY Vol. 80 No. 3 2010