Synthesis propionic acid

Ethylene reacts with carbon monoxide and water in the presence of nickel carbonyl to give propionic acid in high yield. If care is taken to maintain a high concentration of propionic acid in the reaction mixture and the temperature, which is normally 300 in the propionic acid synthesis, is decreased to 240 °C propionic acid anhydride is formed in high yield in the presence of Ni(CO)4. Propionic acid ethyl ester is the main product in the reaction of ethylene, carbon monoxide and water (low water concentration must be applied) with cobalt carbonyls instead of Ni(CO)4. The conversion of ethylene with carbon monoxide in dilute alkaline medium with the aid of potassium nickel cyanide gives propionyl propionic acid [403-405]. At higher temperatures and without pH correction in the same reaction mainly polyketones with the sequences -(CHg-CHg-CO)- are formed. If the reaction is carried out in absence of water or alcohols and in presence of palladium iodide as catalyst, a mixture of hexenolide isomers is the main product. Colorless polyketones of the same structure are obtained if an excess of ethylene is treated with carbon monoxide in the presence of complex palladium salts as catalysts in an alcoholic hydrogen halide solution at 100 °C and 700 atm [406]. 

Other possible chemical synthesis routes for lactic acid include base-cataly2ed degradation of sugars oxidation of propylene glycol reaction of acetaldehyde, carbon monoxide, and water at elevated temperatures and pressures hydrolysis of chloropropionic acid (prepared by chlorination of propionic acid) nitric acid oxidation of propylene etc. None of these routes has led to a technically and economically viable process (6). 

With the exception of acetic, acryUc, and benzoic all other acids in Table 1 are primarily produced using oxo chemistry (see Oxo process). Propionic acid is made by the Hquid-phase oxidation of propionaldehyde, which in turn is made by appHcation of the oxo synthesis to ethylene. Propionic acid can also be made by oxidation of propane or by hydrocarboxylation of ethylene with CO and presence of a rhodium (2) or iridium (3) catalyst. 

Propionic acid, 2-bromo-3-(3-indolyl)-methyl ester rearrangement, 4, 279 Propionic acid, 3-(3,4-dimethyoxyphenyl)-dihydrocoumarin synthesis from, 3, 848 Propionic acid, indolyl-synthesis, 4, 232 Propionic acid, 3-(l-indolyl)-sodium salt pyrolysis, 4, 202 Propionic acid, 3-(3-indolyl)-intramolecular acylation, 4, 220, 221 Propionic acid, 3-phenoxy-chroman-4-one synthesis from, 3, 855 Propionic acid, 3-(3-phenylisoxazoI-5-yl)-bromination, 6, 25... 

Propionic acid, pyrrolyl-synthesis, 4, 232 Propionic acid, 3-(2-pyrrolyl)-intramolecular acylation, 4, 221 Propylamine, oxadiazolyl-synthesis, 6, 445... 

Synthesis of Quinine. This required a parallel series of operations jn which the still unknown substance Aomomeroquinenine (3-vinylpiperi-dine-4-propionic acid) replaced its dihydro-derivative, Aomocincholoipon, for the final condensation with ethyl quininate. The first step was taken by ProStenik and Prelog,who converted cinchonine to cinchqnjcjn ... 

In 1909, Thiele and Landers reported the synthesis of p- (3-methoxy-isoxazol-5-yl)-propionic acid (77), from the corresponding chloride or bromide (76). In 1961, a similar reaction was reported for 3-chloro-5-arylisoxazoles, enabling the synthesis of 3-hydroxy-5-phenyl-... 

Johnson s classic synthesis of progesterone (1) commences with the reaction of 2-methacrolein (22) with the Grignard reagent derived from l-bromo-3-pentyne to give ally lie alcohol 20 (see Scheme 3a). It is inconsequential that 20 is produced in racemic form because treatment of 20 with triethyl orthoacetate and a catalytic amount of propionic acid at 138 °C furnishes 18 in an overall yield of 55 % through a process that sacrifices the stereogenic center created in the carbonyl addition reaction. In the presence of propionic acid, allylic alcohol 20 and triethyl orthoacetate combine to give... 

The tetramerization of suitable monopyrroles is one of the simplest and most effective approaches to prepare porphyrins (see Section 1.1.1.1.). This approach, which is best carried out with a-(hydroxymethyl)- or ot-(aminomethyl)pyrroles, can be designated as a biomimetic synthesis because nature also uses the x-(aminomethyl)pyrrole porphobilinogen to produce uroporphyrinogen III. the key intermediate in the biosynthesis of all kinds of naturally occurring porphyrins, hydroporphyrins and corrins. The only restriction of this tetramerization method is the fact that tnonopyrroles with different -substituents form a mixture of four constitutionally isomeric porphyrins named as porphyrins I, II, III, and IV. In the porphyrin biosynthesis starting from porphobilinogen, which has an acetic acid and a propionic acid side chain in the y6-positions, this tetramerization is enzymatically controlled so that only the type III constitutional isomer is formed. 

Synthesis via o-QM 3 and Reaction Behavior of 3-(5-Tocopheryl) propionic Acid... 

Tocopheryl)propionic acid (50) is one of the rare examples that the o-QM 3 is involved in a direct synthesis rather than as a nonintentionally used intermediate or byproduct. ZnCl2-catalyzed, inverse hetero-Diels-Alder reaction between ortho-qui-none methide 3 and an excess of <2-methyl-C,<9-bis-(trimethylsilyl)ketene acetal provided the acid in fair yields (Fig. 6.37).67 The o-QM 3 was prepared in situ by thermal degradation of 5a-bromo-a-tocopherol (46). The primary cyclization product, an ortho-ester derivative, was not isolated, but immediately hydrolyzed to methyl 3-(5-tocopheryl)-2-trimethylsilyl-propionate, subsequently desilylated, and finally hydrolyzed into 50. 

FIGURE 6.37 Synthesis of 3-(5-tocopheryl)-propionic acid (50) by trapping the intermediate ortho-QM 3 with a ketene acetal. Reaction products of 50 are formed in complete analogy to a-tocopherol (1). 

Rosenau, T. Potthast, A. Kosma, R Habicher, W. D. Novel tocopherol compounds XI. Synthesis bromination and oxidation reactions of 3-(5-tocopheryl)propionic acid. Synlett 1999, 3, 291-294. 

A further extension to this concept was (dimethylsilyl)propionic acid linker 75 used for the solid-phase synthesis of aryl-containing organic compounds [86], The linker was cleaved smoothly with TFA and has been used for the synthesis of compounds which involved alkylation, acylation, and Mitsunobu reactions. 

In mammals and in the majority of bacteria, cobalamin regulates DNA synthesis indirectly through its effect on a step in folate metabolism, catalyzing the synthesis of methionine from homocysteine and 5-methyltetrahydrofolate via two methyl transfer reactions. This cytoplasmic reaction is catalyzed by methionine synthase (5-methyltetrahydrofolate-homocysteine methyl-transferase), which requires methyl cobalamin (MeCbl) (253), one of the two known coenzyme forms of the complex, as its cofactor. 5 -Deoxyadenosyl cobalamin (AdoCbl) (254), the other coenzyme form of cobalamin, occurs within mitochondria. This compound is a cofactor for the enzyme methylmalonyl-CoA mutase, which is responsible for the conversion of T-methylmalonyl CoA to succinyl CoA. This reaction is involved in the metabolism of odd chain fatty acids via propionic acid, as well as amino acids isoleucine, methionine, threonine, and valine. 

The reaction of potassium 3-amino-4-oxo-3,4-dihydroquinazoline-2-thiolate 62 with a-bromophenylacetic acid 63 resulted in the formation of (3-amino-4-oxo-3,4-dihydroquinazolin-2-ylsulfanyl)-phenyl-acetic acid methyl ester 64 which on alkali treatment and subsequent acidification resulted in the synthesis of 2-phenyl- 1-thia-4,4a,9-triaza-anthracene-3,10-dione 65 <1999JCR(S)86>. Similarly, the reaction of potassium 3-amino-5,6-dimethyl-4-oxo-3,4,4a,7a-tetrahydrothieno[2,3- pyrimidine-2-thiolate 66 with a-bromo-ester 67 resulted in the formation of 2-(3-amino-5,6-dimethyl-4-oxo-3,4,4a,7a-tetrahydrothieno[2,3- / pyrimidin-2-ylsulfanyl)-propionic acid ethyl ester 68. Subsequent treatment with alkali followed by acidification resulted in the formation of 2,3,7-trimethyl-3a,9a-dihydro-l,8-dithia-4a,5,9-triazacyclopenta[ ]naphthalene-4,6-dione 69 <2000JHC1161>... 

A mutant E. coli strain LS5218 (fadR atoC) was employed for the synthesis of P(3HB-co-3HV) copolymer since this mutant strain constitutively expresses the enzymes involved in the transport and utilization of short chain fatty acids [58, 59]. P(3HB-co-3HV) could be synthesized by a recombinant E. coli strain LS5218 harboring the R. eutropha PHA biosynthesis genes when propionic acid or valeric acid was added as a cosubstrate [58,60]. The P(3HB-co-3HV) copolymer consisting of up to 40 mol% of 3HV could be produced. An alternative method that allowed synthesis of P(3HB-co-3HV) using propionic acid or valeric... 

The successful use of crop plants as a production method for biopolymer not only depends on the amount of PHA accumulated in plants but also on the type and quality of the PHA synthesized. Since poly(3HB) is a polymer with poor physical characteristics [16], it was important to engineer plants for the synthesis of PHA co-polymers with better physical characteristics. Poly(3-hydroxybu-tyrate-co-3-hydroxyvalerate) [poly(3HB-co-3HV)] is the best studied co-poly-mer. Poly(3HB-co-3HV) has lower crystallinity, and is more flexible and less brittle than poly(3HB) homopolymer [16]. Synthesis of poly(3HB-co-3HV) in bacteria was first achieved by fermentation of R. eutropha on glucose and propionic acid [2]. For a number of years, production of poly(3HB-co-3HV),... 

H. Ihre, A. Hult, J. M. J. Frechet, and I. Gitsov, Double-stage convergent approach for the synthesis of functionalized dendritic aliphatic polyesters based on 2,2-bis(hydroxymethyl)propionic acid, Macromolecules, 31 (1998) 4061 1068. 

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