(Official Hive Translator)
09-29-03 04:12
No 461624
(Rated as: good read)
This issue has been brought up a couple of times on The Hive (Post 447654 (FriendlyFinger: "Propiophenone via carboxylic acid & tosic ??", Chemistry Discourse),Post 436844 (jimwig: "some old info on propionic acid", Chemistry Discourse)). However, no exact info ever was obtained on this most interesting matter.
Now i found a couple of interesting patents and from them it seems obvious that, even if this rxn CAN bee applied to MEK to get Et-COOH, in any case it is not as simple as it seemed, not at all.
Here is a quote from Patent GB647094:
It is generally accepted that most oxidising agents, when acting upon methyl alkyl ketones tend to favour cleavage of the opposite type, namely between the carbonyl group and the longer alkyl residue giving rise for instance in the case of methyl isobutyl ketone to mixtures of carboxylic acids in which acetic and isobutyric acids predominate.
It may however be pointed out that it is known that aromatic carbioxylic acids may be prepared in good yields from aryl methyl ketones by the action of alkali metal hypochlorites or alkali metal hypoobromites and that unsaturated carboxylic acids have been obtained in good yields by the treatment of the corresponding unsaturated aliphatic methyl ketones. A few derivatives of saturated aliphatic acids have been obtained in good yields by a similar method using sodium hypobromite solutions. Only one instance describing the successful use of hypochlorite appears to have been recorded and this is in connection with the preparation of trimethyl acetic acid from pinacolone.
On the other hand it has been found that 3:3 dimethylheptan-2-one was hardly attacked by hypochlorite.
In view of the prior knowledge it could by no means be foreseen that solutions of alkali metal hypochlorites or even the corresponding hypobromites could be used in the treatment of methyl isobutyl ketone to produce isovaleric acid of good quality and in economically useful yields.
So, as you can see, while there is a vague mention that haloform rxn sometimes does proceed 'correctly' with hypobromite, it seems quite unlikely that things will work out w/straight hypochlorite.
Another very useful tidbit of information was found in Patent US3994897:
...It is known from Houben-Weyl, Methoden der organischen Chemie, volume 8, pages 415-416, that carboxylic acids can be manufactured by oxidation of methyl ketones with hypohalites in an aqueous medium. The publication recommends dispersing the ketone by means of oxidation-resistant emulsifiers or carrying out the reaction in the presence of dioxane; all the examples were carried out in this way. In most cases the reaction only takes place satisfactorily with hypobromite solutions, which are more expensive and less stable than hypochlorite solutions.
...Compared to conventional processes, the process of the invention suprisingly gives carboxylic acids more simply and more economically and in some cases in better yield and better purity, and permits the manufacture, even on an industrial scale, of a large number of carboxylic acids by using a hypochlorite.
...The following methyl ketones are examples of suitable starting materials II: pinacolone, acetone, mesityl oxide, cinnamalacetone, 2-methylhept-4-en-6-one, 2-methylheptan-6-one, 2-methylhept-1-en-6-one, benzalacetone, furylideneacetone, dodecyl methyl ketone, cyclohexyl methyl ketone, benzyl methyl ketone, phenyl methyl ketone.
The nature of the invention, as it appears, is conducting the rxn with several catalysts: sulfonic amide chlorides (like Chloramine); some bromine or iodine salt; a polymerisation inhibitor - a thiosulfate or sulfide or several others. What seems very intriguing though is that all the examples seem to lack the essential details or something - at least, no mention of bromides nor a polymerisation inhibitors is ever present in ANY of the examples
I would bee infinitely grateful if someone beesides me could take a look at that patent and say what he thinks: i myself am not certainm that i understood it correctly. So if someone's interested...
Anyway, it seems reasonable to assume that by using the conditions from the second patent we will arrive at the wanted target. So here are some representative procedures to give you a general idea:
Patent GB647094:
EXAMPLE 1.
250 grams of methyl isobutyl ketone vere treated with 4750 ml of commercial sodium hypochlorite solution (14-15 % available chlorine) which was added slowly with stirring. During the addition the temperature was kept between 7-10 C by external cooling. Stirring was continued for five hours at this temperature and then for a further two hours at room temperature. After standing overnight, the lower layer (containing chloroform and unchanged ketone) was separated and 40 g of ketone were recovered by distillation.
The aqueous layer, after concentration to 3,5 L, was acidified with 400 ml of dilute sulphuric acid ( 33,3 % v/v) and the crude acid which separated was distilled to give isovaleric acid, boiling range 175-178 C; yield 110 grams ( 51% of theory on ketone consumed).
Patent US3994897:
EXAMPLE 1
50 parts of pinacolone are slowly added in portions in the course of 15 minutes to a mixture of 750 parts by volume of water, 660 parts by volume of sodium hypochlorite solution (containing 113 parts of sodium hypochlorite) and 0.5 part of amidosulfonic acid at 5 DEG C. The mixture is cooled with ice water. The temperature rises to 23 DEG C and the mixture turns cloudy; it is then stirred for a further 3 hours at room temperature. The chloroform formed is separated off, and the aqueous solution is acidified with 55 parts by volume of concentrated sulfuric acid (96% strength by weight) and steam-distilled. Pivalic acid (trimethylacetic acid) is separated off and the aqueous phase is extracted once with 40 parts by volume of ether. Yield: 42.8 parts of pivalic acid (83.8% of theory); melting at 33 DEG C.
EXAMPLE 5
50 parts of 2-methylheptan-6-one are added slowly, in portions, to a mixture of 900 parts by volume of sodium hypochlorite solution (containing 149 parts of sodium hypochlorite), 200 parts by volume of water and 1.5 parts of diaza-bicyclo [2,2,2] octane at from 32 DEG to 36 DEG C. After a further reaction time of 1.5 hours at 40 DEG C, 12 parts of sodium bisulfite are added, the organic phase is separated off, the aqueous phase is acidified and the organic phase which forms is again separated off. On distilling the combined organic phases, 22.1 parts of 5-methylhexanoic acid (43.6% of theory) are obtained at from 73 DEG to 103 DEG C at 0.05 mm Hg.
I hope this post of mine will stir up some interest since propionic acid, despite its usage in food industry, is a heavily controlled chemical.
,Antoncho
P.S. I bet that this improvement to hypochlorite oxidation will also do in application to THF-->GBL oxidation (NaOCl - max 60% yield, in situ NaOBr - 73%). Huh?
(Official Hive Translator)
09-30-03 04:06
No 461844
Here’s a useful addition (from Buler’s Organic Syntheses):
"...potassium hypoclorite solution is prepared by treating CaOCl2 (~35%) with aq. K2CO3, CaCO3 is filtered and washed with water."
As you can see, there is not much detail in there, but perhaps there isn't a need for more
. BTW, in that example KOCl is reacted with aq/methanolic o-MeO-benzyl alcohol to give 4-MeO-BA in a 51%
yield.Antoncho
(Hive Bee)
09-30-03 04:52
No 461856
Ullmanns 6th:
Industrially, propionic acid is currently produced almost exclusively by three different processes:
1) Carbonylation of ethylene with carbon monoxide and water
2) Oxidation of propanal
3) Direct oxidation of hydrocarbons
Processes such as production of propionic acid as a byproduct in the synthesis of hydroxylammonium salts from 1-nitropropane [108-03-2] [33] (® Hydroxylamine - 4.4. Acid Cleavage of Nitroalkanes), by wood distillation, or by nitric acid oxidation of 1-propanol [62309-51-7] have become obsolete, although the latter gives propionic acid in 90 % yield [34]. Synthesis of propionic acid via the alkali melt of an n- and isopropanol mixture could never compete successfully with other pro-cesses, although propionic acid was obtained with > 98 % yield [35] , [36]. The carbonylation of ethanol [64-17-5] [37] and acetic acid [64-19-7] [38] have also not yet been carried out industrially.
The Koch synthesis has been investigated intensively [39] , [40]. As a carbonylation reaction of ethylene [74-85-1] in a strongly acidic medium, it is a variant of the Reppe synthesis. However, compared with the latter it never achieved much industrial significance and was carried out with little success.
Other possible sources of propionic acid, which are not used industrially for economic reasons, are its formation as a byproduct in the high- and low-pressure carbonylation of methanol [67-56-1] to give acetic acid (2 % formation of propionic acid), the atmospheric oxidation of n-butene [25167-67-3] (4 % formation of propionic acid), and the direct reaction of ethylene, carbon monoxide, and water over noble-metal catalysts [41][42][43][44][45][46][47][48][49].
Processes for making propionic acid accessible specifically by C1- chemistry have yet to be assessed for their future importance. Two-step reactions have been described, in which propionic acid is obtained directly from synthesis gas (20 – 60 bar, 150 – 160 °C, Rh catalysts) [50] , [51]. With the current availability of ethylene and naphtha these processes are, however, not yet competitive.
It is sometimes desirable, to use propionic acid produced by natural methods, particularly for the use of propionic acid in flavors and fragrances. Appropriate microbiological and enzymatic processes have been developed, which are usually based on the anaerobic fermentation of starch or sugars [52][53][54]. However, the expensive production of this "natural" propionic acid limits its use to special areas of application.
[33] Ullmann, 3rd ed., 8, 744.
[34] Celanese, Patent GB771583 , 1957.
[35] SRI-Process Economics Program, no. 42, A 1, Menlo Park 1975, pp. 18.
[36] Dow Chemical, Patent US1926068, 1933 (C. J. Strosacker, C. C. Kennedy, E. L. Pelton).
[37] Ullmann, 4th ed., 9, 161 ff.
[38] Texaco Dev., Patent DE3124720, 1981 (J. F. Knifton). = Patent GB2078732
[39] M. Sittig, Chem. Proc. Monogr. no. 8 (1965) p.76.
[40] [39] no. 23 (1966) pp. 105.[39]: M. Sittig, Chem. Proc. Monogr. no. 8 (1965) p.76.
[41] Monsanto, Patent BE793203, 1971 (M. D. Forster, D. E. Morris). = Patent US3186490
[42] Monsanto, Patent US3989748, 1968 (F. E. Paulik, A. Hershman, J. F. Roth).
[43] Monsanto, Patent US3989747, 1968 (J. H. Craddock, J. F. Roth, A. Hershman, F. E. Paulik).
[44] BP Chemicals, Patent DE2101909, 1970 (G. E. Foster, J. R. Bethell).
[45] Monsanto, Patent BE796294, 1972 (D. E. Morris). = Patent GB1367607
[46] BP Chemicals, Patent GB1363961, 1972 (M. J. Wriglesworth, D. J. Westlake).
[47] Monsanto, Patent US3944603, 1972 (D. E. Morris).
[48] Monsanto, Patent DE2263442, 1972 (D. Forster, D. E. Morris). = Patent US3816490
[49] BASF, Patent DE2604545, 1976 (K. Schwirten, W. Disteldorf, W. Eisfeld, R. Kummer). = Patent GB1565716
[50] E. Drent, ACS Symp. Ser. 328 (1987) 154 – 175.
[51] Texaco, Patent US4362822, 1981 (J. F. Knifton).
[52] P. Blanc, G. Goma, Biotechnol. Lett. 11 (1989) 189 –194.
[53] M. J. T. Carrondo, J. P. S. G. Crespo, M. J. Moura, Appl. Biochem. Biotechnol. 17 (1988) 295 – 312.
[54] H. Dellweg: Biotechnology, vol. 3, Verlag Chemie, Weinheim 1983, p. 472.
(Hive Bee)
10-10-03 07:05
No 463783
For preparation see:
JACS 55, 1647 (1933)
roger2003
(Chief Bee)
10-10-03 07:59
No 463793
(Rated as: excellent)
The Action of Bleaching Powder on Methyl Ethyl Ketone
Charles D. Hurd and Charles L. Thomas
JACS 55, 1646-1649 (1933)
In contrast to the general familiarity of the reaction between acetone and bleaching powder, very little is known of the action of bleaching powder on other ketones. Ethyl methyl ketone was selected to see if the reaction would yield chloroform and calcium propionate or ethylidene chloride and calcium acetate. Only the first of these two possibilities was realized. This provides a convenient source of propionic acid.
The general equation for this type of synthesis is:
2 RCOCH3 + 6 CaOCl2 -> (RCOO)2Ca + 3 CaCl2 + 2 Ca(OH)2 + 2 CHCl3
In this case R represents C2H5-
Experimental Part
Three hundred grams of commercial bleaching powder (24% available chlorine) was made into a paste with 750 mL of water at 15°C. The temperature of the water must be above 10°C, otherwise too viscous a paste results. This mixture was put into a 3-liter flask which was equipped with a dropping funnel, mercury-sealed stirrer and condenser. Then 25 mL of ethyl methyl ketone was gradually introduced with stirring, care being taken to avoid frothing over. The mixture became quite warm and 10 mL of chloroform, a 45% yield, distilled. The refractive index of the distillate was 1.4452 (for chloroform 1.4458; for ethylidene chloride, 1.4165).
The residue in the flask was neutralized with nitric acid. Then more nitric acid was added to liberate the propionic acid, purposely adding less than the calculated amount to avoid subsequent extraction of nitric acid. Even with an excess, however, ether extracts but insignificant quantities of nitric acid from a dilute aqueous solution.
The acidified solution was made up to 2000 mL with water. An aliquot portion of 500 mL of this was extracted four times with ether for the organic acid and the extracts made up to 250 mL Titration of an aliquot portion of 50 mL of this ether solution with 0.2016 N alkali required 27.5 mL This corresponds to a yield of 8.18 g or 40.7% of the calculated amount of propionic acid.
(Hive Bee)
10-10-03 08:35
No 463795
Propanol is converted over the aldehyde to acid (in 91% yield)in one step with CuO
Patent US1951280
Patent US2173111
Patent US2294984
(Official Hive Translator)
10-15-03 01:26
No 464741
Well, Rhodium, you've found the answer at last
Now we can put a firm period on this issue instead of a question mark.
Of course, the procedure above needs to bee twitched as the hypochlorite to MEK ratio is way too big. I can see a potential problem here as well
Antoncho