Org. Synth. 1947, 27, 1
DOI: 10.15227/orgsyn.027.0001
β-ALANINE
Submitted by Jared H. Ford
Checked by Homer Adkins and James M. Caffrey.
1. Procedure
In a
2-l. three-necked flask equipped with a mechanical stirrer, a thermometer, and a dropping funnel is placed
185 g. (0.55 mole) of technical barium hydroxide octahydrate. The flask is heated on a
steam bath in a
hood. When the
barium hydroxide has dissolved in its water of crystallization, the stirrer is started and
70.1 g. (1.00 mole) of β-aminopropionitrile (p. 93) is added dropwise over a period of 40 minutes. The temperature is maintained at 90–95° during the addition and for 40 minutes thereafter. Forty grams of asbestos filter aid
(Note 1) and 1 l. of hot water are added, and the mixture is saturated with
carbon dioxide (Note 2) while the temperature is held at 85–90°. The mixture is filtered with suction, the precipitate is returned to the flask with 500 ml. of hot water, and the mixture is heated and stirred for 20 minutes. After the
barium carbonate has been filtered the washing procedure is again repeated with a second 500 ml. of hot water. The combined filtrates and washings are concentrated under reduced pressure on the steam bath
(Note 3) until solid material separates. To the residue are added 200 ml. of hot water and
0.5 g. of decolorizing carbon (Note 4). The resulting solution is warmed on the steam bath for a few minutes and then filtered into a weighed
500-ml. Erlenmeyer flask. The flask is heated on a steam bath, and a jet of clean compressed air is directed at the surface of the solution. When the total weight of the solution is 130 g., it is cooled to 15–20° and diluted slowly with
400 ml. of methanol. After the solution has stood for several hours in the refrigerator, the product is filtered with suction and washed with two
100-ml. portions of methanol. The yield of
β-alanine melting at
197–198° (dec.) is
75–80 g. (
85–90%).
2. Notes
1.
Standard Super-Cel (Johns-Manville, Inc.) was used.
2.
Either
carbon dioxide gas or Dry Ice may be used, and the saturation may be completed in 15–20 minutes by either method. The
pH of the saturated solution is about 8–9 when tested with a universal indicator paper, such as Alkacid or Hydrion.
3.
The submitter used a special apparatus suitable for the rapid evaporation of water under reduced pressure. The checkers used standard flasks.
4.
The solution is nearly colorless at this point, but the
carbon aids in the removal of finely divided insoluble material.
3. Discussion
β-Alanine has been prepared by the catalytic reduction of
cyanoacetic acid,
1 esters,
2 or salts;
3 by heating
acrylonitrile,
4 β-aminopropionitrile,
5 bis-(β-cyanoethyl) amine,
6 β-hydroxypropionitrile,
7 β-alkoxypropionitriles,
8 bis-(β-cyanoethyl) ether,9 or bis-(β-cyanoethyl) sulfide9 with aqueous
ammonia at 150–225°; by the hydrolysis of
β-aminopropionitrile with concentrated
hydrochloric acid and subsequent removal of the acid with anion-exchange resins;
10 by hydrolysis of
β-phthalimidopropionitrile prepared from
phthalimide and
acrylonitrile;
11 from
β,β'-iminodipropionic acid,
β,β'-iminopropionitrile, or diethyl-β,β'-iminopropionate through preliminary conversion with
phthalic anhydride at 200° to the corresponding phthalimide and subsequent hydrolysis.
12 The method as described above has been published.
13 Additional references to methods of preparation are given in connection with a procedure for making
β-alanine from
succinimide through the action of
potassium hypobromite.
14,15
Appendix
Chemical Abstracts Nomenclature (Collective Index Number);
(Registry Number)
β,β'-iminopropionitrile
diethyl-β,β'-iminopropionate
hydrochloric acid (7647-01-0)
ammonia (7664-41-7)
methanol (67-56-1)
carbon dioxide (124-38-9)
phthalic anhydride (85-44-9)
carbon (7782-42-5)
Phthalimide (85-41-6)
β-hydroxypropionitrile (109-78-4)
cyanoacetic acid (372-09-8)
barium hydroxide (17194-00-2)
barium carbonate (513-77-9)
barium hydroxide octahydrate (12230-71-6)
β-Alanine (107-95-9)
Succinimide (123-56-8)
β-Aminopropionitrile (151-18-8)
acrylonitrile (107-13-1)
bis-(β-cyanoethyl) amine (111-94-4)
bis-(β-cyanoethyl) ether (1656-48-0)
bis-(β-cyanoethyl) sulfide (111-97-7)
β-phthalimidopropionitrile
potassium hypobromite
β,β'-iminodipropionic acid
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