(Newbee)
09-17-03 10:52
No 459617
(Rated as: good read)
I wanted to post this in the 'acetonedicarboxylic acid'-thread, which seemed appropriate, but couldn't (thread too old?). Well anyway, here is another synth for the title substance. No new concepts involved but it states to give excellent yields and looks simple enough. Somebee want to demonstrate his/her German skills
?The synthesis is taken from
'Reaktionen und Synthesen im organisch-chemischen Praktikum und Forschungslaboratorium' by Lutz Friedjan Tietze und Theophil Eicher, 2. neub. Aufl, - Georg Thieme Verlag Stuttgart - New York, p. 514, 'Q-11a Acetondicarbonsäure'
and it goes like that:
'Apparatur: 500 ml-Dreihalskolbeen mit KPG-Rührer, Innenthermometer und Gasableitungsrohr mit Blasenzähler und Schlauch. Die Reaktion muß in einem gut ziehenden Abzug durchgeführt werden.
Zu 94ml Oleum [note: SO3-content nowhere stated, other procedures use 20% or so] gibt man portionsweise unter Rühren bei -5 bis 0°C (Innentemp.) 42.0g (0.20 mol) Citronensäure-Monohydrat. Anschließend wird bei RT gerührt, bis die Kohlenmonoxid-Entwicklung nachläßt, und erhitzt dann auf 30°C. Sobald keine Kohlenmonoxid-Entwicklung mehr auftritt, bricht man die Reaktion ab. Es hat sich eine klare, gelbe Lösung gebildet
Zur Aufarbeitung wird die Reaktionslösung auf 0°C abgekühlt und vorsichtig mit 145g Eis versetzt (maximale Innentemp. 10 °C; Zeitbedarf ca. 20 min). Man kühlt erneut auf 0°C ab, läßt 1h bei dieser Temperatur stehen und filtert die ausgefallenen Kristalle über eine Glasfilternutsche (P2) ab. Die Kristalle werden zur Beseitigung von anhaftender H2SO4 zweimal mit Essigsäure-ethylester verrührt und filtriert. anschließend wird mit 50 ml Ether nachgewaschen und i.Vak. getrocknet. Man erhält 27.2g (93%) farblose Kristalle vom Schmp. 133°C (Zers.). Die nach dieser Methode hergestellte Acetondicarbonsäure zeigt nach 1 Woche keine Veränderung. Falls eine längere Lagerung vorgesehen ist, sollte aus Essigsäure-ethylester umkristallisiert werden.'
(Hive Bee)
09-17-03 12:51
No 459646
(Rated as: good read)
From Organic Syntheses, CV1, 10:
Acetonedicarboxylic acid
In a 5-l. round-bottomed flask (Note 1), fitted with a mechanical stirrer, is placed 3 kg. (1555 cc.) of fuming sulfuric acid (20 per cent of free sulfur trioxide). Then the flask is cooled very efficiently with a thick pack of ice and salt, until the temperature of the acid reaches −5° (Note 2). The stirring is started, and 700 g. (3.64 moles) of finely powdered u. s. p. citric acid is added gradually. The speed of the addition is regulated according to the temperature of the reaction mixture. The temperature should not rise above 0° until half of the citric acid has been added, after which the temperature should not be allowed to exceed 10° until the reaction is complete. The addition requires three to four hours, provided efficient cooling is used. The citric acid should be in solution at the end of this time; if not, the stirring should be continued until it has dissolved completely.
The temperature of the reaction mixture is allowed to rise gradually until a vigorous evolution of gas commences; at this point the flask is cooled with ice water to stop the excessive frothing, but cooling is not carried far enough to stop the evolution of gas entirely (Note 3). After the more vigorous foaming has ceased, the reaction mixture is raised to about 30° and kept there until no more foaming occurs. A convenient way of determining this point is to stop the stirring for a moment and allow the mixture to remain quiet. After a minute or so, a clear brown liquid giving off very few gas bubbles should result. This general procedure requires two to three hours.
The reaction mixture is cooled down again with ice and salt until the temperature reaches 0°, then 2400 g. of finely cracked ice is added in small portions at such a rate that the temperature does not rise above 10° until one-third of the ice has been added. Then the temperature may be allowed to rise to 25–30°. The addition of the ice requires about two hours; after this, the mixture is cooled again to 0° (Note 4) and then filtered as rapidly as possible through a funnel fitted with a filtros plate (Note 5). The crystals are thoroughly pressed and sucked as dry as possible. The acetonedicarboxylic acid is light gray to white in color. After the suction and pressing have removed practically all of the sulfuric acid, the crystals are transferred to a beaker and stirred with sufficient ethyl acetate (about 200–250 cc.) to make a thick paste. The crystals are filtered with suction. If acetonedicarboxylic acid entirely free from sulfuric acid is desired, the washing with ethyl acetate should be repeated. The yield of practically dry acetonedicarboxylic acid varies from 450–475 g. (85–90 per cent of the theoretical amount) (Note 6). This may be used directly for the preparation of the ester (p. 237). The acid itself is not stable and after a few hours gradually decomposes (Note 7).
2. Notes
1. The reaction must be carried out in a good hood, since a large amount of carbon monoxide is liberated.
2. The use of a very efficient ice and salt mixture around the reaction flask is necessary if the reaction is to be carried out within the time indicated. It is very necessary to regulate the temperature as directed, since a considerably lower yield is obtained if the temperature rises.
3. Some cooling is necessary, or the rapid evolution of gas will cause the reaction mixture to foam over with consequent loss of material.
4. Vigorous cooling before final filtration of the acetonedicarboxylic acid is essential to good yields, since the acid is fairly soluble in the reaction mixture.
5. The filtros plate for filtration can be very conveniently sealed into the Büchner funnel with a paste of water-glass and amorphous silica which is then hardened with concentrated sulfuric acid.
6. If the acid is to be esterified at once, careful drying from ethyl acetate is not necessary.
7. However, it has been observed that if the acid is purified by recrystallization from ethyl acetate and thoroughly dried it undergoes no decomposition, at least over a seven-month period, when kept at room temperature in a desiccator (i).
3. Discussion
Acetonedicarboxylic acid can be prepared from citric acid by the action of concentrated (ii) or fuming sulfuric acid (iii). The procedure described is a slight modification of that by Willstätter and Pfannenstiehl.3 While it is more complex than the details given by Ingold and Nickolls,3 it gives somewhat higher yields. The method of Ingold and Nickolls has been checked and found to have the advantage of requiring much less time.
This preparation is referenced from:
Org. Syn. Coll. Vol. 1, 237
Org. Syn. Coll. Vol. 1, 408
Org. Syn. Coll. Vol. 1, 485
Org. Syn. Coll. Vol. 4, 816
References and Notes
i.) Wiig, J. Phys. Chem. 32, 961 (1928).
ii.) Pechmann, Ber. 17, 2543 (1884).
iii.)Pechmann, Ann. 261, 155 (1891); Peratoner and Strazzeri, Gazz. chim. ital. 21, I, 295 (1891) [Chem. Zentr. I, 967 (1891)]; Jerdan, J. Chem. Soc. 75, 809 (footnote) (1889); Willstätter and Pfannenstiel, Ann. 422, 5 (1921); Ingold and Nickolls, J. Chem. Soc. 121, 1642 (1922); Wiig, J. Phys. Chem. 32, 961 (1928).
C, Weygand in his book, titled "Organisch-Chemische Experimentierkunst", J.A. Barth-Verlag, Leipzig 1948, uses basically the same procedure as quoted from the "Tietze-Eicher". In his synthesis he uses oleum with 15% SO3...
Quidquid agis, prudenter agas et respice finem!
(Hive Bee)
09-18-03 00:29
No 459717
(Rated as: good read)
Ullmann`s:
Acetonedicarboxylic Acid
Acetonedicarboxylic acid [542-05-2] , 3-oxoglutaric acid, b-ketoglutaric acid, 3-oxopentane dicarboxylic acid, HOOC–CH2–CO–CH2–COOH, Mr 146.10, was first isolated and described by V. PECHMANN [48] , [49].
Physical Properties. Acetonedicarboxylic acid forms colorless crystals that are readily soluble in water and ethanol, and sparingly soluble in trichloromethane and diethyl ether. It melts with decomposition at 138 °C. The dissociation constants (in 0.01 M solution) are K125= 4.68×10–4 and K225= 5.37×10–5 [50].
Chemical Properties. On heating above its melting point, acetonedicarboxylic acid decomposes into carbon dioxide and acetone [49]. When acetonedicarboxylic acid is warmed in water, a two-step decomposition occurs with acetoacetic acid [541-50-4] as an intermediate that decomposes further to acetone and carbon dioxide [50]. The decomposition is catalyzed by metal ions and protons [51]. Phenols react with acetonedicarboxylic acid in the presence of dehydrating agents to form coumarin derivatives [52][53][54].
Production. Acetonedicarboxylic acid is produced from citric acid [77-92-9] by many industrial processes that differ only slightly [55],[56]. Citric acid is treated with oleum and reacts to yield acetonedicarboxylic acid via decarbonylation and dehydration.
Other possible production methods include reaction of acetone with carbon dioxide [57] , [58] , oxidation of citric acid with chlorosulfuric acid [59] , or reaction of ketene with phosgene [60].
Uses. Acetonedicarboxylic acid is an important starting material in the production of pharmaceutically active alkaloids [61][62][63]. It is also suitable as a stabilizer for natural fats and oils [64] , [65].
Storage and Quality Specifications. Large quantities of acetonedicarboxylic acid can be stored for short periods in tightly closed polyethylene containers in refrigerated areas. The acid must not be stored in metal containers. Laboratory-scale quantities of the pure substance can be kept for longer periods over phosphorus pentoxide in a desiccator [66]. The commercial product has a concentration of ca. 98 %; the purity is determined by titration.
Toxicology. Acetonedicarboxylic acid can cause irritation and acid burns to the eyes, respiratory passages, and skin.
References
[48] H. v. Pechmann, Ber. Dtsch. Chem. Ges. 17 (1884) 929, 2542.
[49] H. v. Pechmann, Justus Liebigs Ann. 261(1891) 155.
[50] R. W. Hay, K. N. Leong, J. Chem. Soc. A 1971, 3639.
[51] J. E. Prue, J. Chem. Soc. 1952, 2331.
[52] H. P. Kansara, N. H. Shah, J. Univ. Bombay Sci. 17 A (1948) 47.
[53] K. A. Thakar, J. Indian Chem. Soc. 40 (1963) 397.
[54] V. M. Dixit, A. N. Kanakudati, J. Indian Chem. Soc. 28 (1951) 323.
[55] Beilstein, 3, 789; 3 (1), 275; 3 (2), 482; 3 (3), 1369.
[56] R. Adams, H. M. Chiles, C. F. Rassweiler, Organic Syntheses CV 1, 10 http://www.orgsyn.org/orgsyn/prep.asp?pr
[57] Mitsui Toatsu Chem Inc., JP-Kokai 75 71 625, 1975 (M. Kawamata, H. Tanabe).
[58] Montedison, Patent DE2429627 , 1974 (E. Alneri, G. Bottaccio, V. Carletti, G. Lana). = Patent US3912778
[59] C. H. Boehringer Sohn, Patent DE1160841 , 1961 (F. Gerner).
[60] Akzo, Patent DE2409342 , 1974 (N. Heyboer). = Patent US3963775
[61] R. C. Menzies, R. Robinson, J. Chem. Soc. 125 (1924) 2163.
[62] Sadolin + Halmblad, Patent GB791770 , 1958 (N. Elming, P. Nedenskov).
[63] C. Schöpf, G. Lehmann, Justus Liebigs Ann. Chem. 518 (1935) 1.
[64] Secretary of Agriculture, Patent US2605186 , 1951 (A. W. Schwab, H. A. Moser, C. D. Evans).
[65] A. Mosca, IT 494 153, 1951.
[66] E. O. Wilg, J. Phys. Chem. 32 (1928) 961.