3- propionic acid reduction

The second method of preparation (shown in Scheme 2) depends on treating dehydroepiandrosterone (prepared from cholestrol or sitosterol) with acetylene to form the 17a-ethnyl-17p-hydroxy derivative, which is carbonated to the 17a-propionic acid. Reduction of the unsaturated acid in alkaline solution yields the saturated acid, which cyclizes to the lactone on acidification. Bromination to the 5,6-dibromo-compound, followed by oxidation of the hydroxyl group to the ketone, and then dehydro-bromination to the 7a-hydroxyl derivative, produces spironolactone when esterified with thiolacetic acid. 

Similar results were obtained on reduction of 3,4,5-trimethylisoxa-zole/ Further examples of such a cleavage were found later. Thus, j8-(3-halogenoisoxazol-5-yl) propionic acids (163) on treatment with sodium amalgam give a mixture of S-cyano-y-ketovaleric and succinic acids (163—> 164) The reaction can be interpreted as a result of... 

An isoindol1 none moiety forms part of the aromatic moiety of yet another antiinflammatory propionic acid derivative. Carboxylation of the anion from -nitro-ethylbenzene (45) leads directly to the propionic acid (46). Reduction of the nitro group followed by condensation of the resulting aniline (47) with phthalic anhydride affords the corresponding phthalimide (48). Treatment of that intermediate with zinc in acetic acid interestingly results in reduction of only one of the carbonyl groups to afford the isoindolone. There is thus obtained indoprofen (49). ... 

A pilot scale UASB reactor was simulated by the dispersed plug flow model with Monod kinetic parameters for the hypothetical influent composition for the three VPA ccmiponents. As a result, the COD removal efflciency for the propionic acid is smallest because its decomposition rate is cptite slow compared with other substrate components their COD removal eflSciencies are in order as, acetic acid 0.765 > butyric acid 0.705 > propionic acid 0.138. And the estimated value of the total COD removal efficiency is 0.561. This means that flie inclusion of large amount of propionic acid will lead to a significant reduction in the total VFA removal efficiency. 

Addifion of oils and oilseeds to the diet is another method that has been used to reduce CH4 emissions (Beauchemin et ah, 2008 Eckard et ah, 2010). Lipid addition to the diet may reduce CH4 emissions by hydrogenation of unsaturated fatty acids, enhanced propionic acid production, and protozoal inhibition (Johnson and Johnson, 1995). Reductions in CH4 of >40% have been demonstrated with lipid supplementation... 

It appeared that, we needed to limit or omit the ethyl iodide if we were going to operate the ethylene carbonylation in ionic liquids. Unfortunately, the previous literature indicated that EtI or HI (which are interconvertible) represented a critical catalyst component. Therefore, it was surprising when we found that, in iodide based ionic liquids, the Rh catalyzed carbonylation of ethylene to propionic acid was still operable at acceptable rates in the absence of ethyl iodide, as shown in Table 37.2. Further, we not only achieved acceptable rates when omitting the ethyl iodide, we also achieved the desired reduction in the levels of ethyl propionate. More importantly, when the reaction products were analyzed, there was no detectable ethyl iodide formed in situ. However, we should note that we now observed traces of ethanol which were normally undetectable in the earlier Ed containing experiments. 

Subsequent insertion of CO into the newly formed alkyl-ruthenium moiety, C, to form Ru-acyl, D, is in agreement with our 13C tracer studies (e.g., Table III, eq. 3), while reductive elimination of propionyl iodide from D, accompanied by immediate hydrolysis of the acyl iodide (3,14) to propionic acid product, would complete the catalytic cycle and regenerate the original ruthenium carbonyl complex. 

Methyloxindole has been prepared by the reduction of a-(2-nitro-phenyl)propionic acid,2 by heating j8-propionylphenylhydrazine with lime3 or with sodium alkoxides,4 and by reduction of the benzoyl derivative of oxindole-3-aldehyde.6... 

Propanol with magnesium in reduction of chlorobenzene, 47, 104 Propionic acid, 2-(2,4,5,7-tetranitro-flcoken-9-ylideneamtnooxv)-, (+)- AND (-)-, 48, 120 Propionyl fluoride, 45, 6 Propiophenone, condensation with paraformaldehyde, 48, 91 -Propylaminc, 45, 85 -Propylhydrazine, 45, 85 C-( -Propyl)-N-phenylnitrone, generation from phenylhydroxylamine and -butyraIdehyde, 46, 97 Purification of tetrahydrofuran (Warning), 46,105 477- Pyran-4-0ne, 2-6-dimethyl-3,5-DIPHENYL-, 47, 54... 

An increase in the elimination half-life in rats was achieved by blocking the benzylic position of the propionic acid chain by introduction of a cyclopropane ring 22 (%F = 88, Vdss = 1 L/kg, f1/2 = 6.3 h) however, in the case of 22, this led to a reduction in the receptor subtype selectivity (EC50 on SI Pi/1,5 = 0.21,123 and 5.1 nM, respectively). Similarly, blocking the benzylic position by cyclizing onto the phenyl ring to form indanylacetic acid 23 resulted in an improved elimination of half-life (%F — 71, Vdss = 0.4L/kg, f1/2 = 6.7h). Acid 23 showed a similar pharmacokinetic profile in the dog and showed efficacy in the rat skin transplantation model when combined with sub-therapeutic doses of CsA. Compound 23 has been reported to be efficacious in the rat EAE model when dosed therapeutically or prophylactically [94—96]. 

Monsanto [117] has developed a way to electrosynthesize by reductive carboxylation the optically active precursor to Naproxen, (S)-2-(6 -methoxy-2 -naphthyl)propionic acid, a drug used to treat arthritis. A more economical route was needed since the US patent expires in 1993 while the market is growing. The electrochemical process is said to cut manufacturing costs by over 50%. Since it uses CO 2 instead of the hazardous HCN used in conventional synthesis, it is also safer. 

But catalytic reduction of the same phenyl propionic acid gives cis cinnamic acid. Therefore by adding hydrogen under various conditions, one can obtain a desired isomer. The conversion of acetylene into olefinic compounds has been carried out not only for the sake of obtaining the adduct, but Michael studied the various addition reactions for the sake of obtaining a desired product cis or trans. For example, he found that the addition of bromine to acetylene-dicarboxylic acid leads predominantly to the formation of trans isomer. 

Coumarin (7.88) is a well-known 6-lactone (six-membered ring) of natural origin found in various preparations such as some tobaccos, alcoholic beverages, and cosmetics. Besides reactions of oxidation, reduction, and conjugation, coumarin is also subject to lactone hydration in vivo and in the presence of microsomes [170-174], The resulting metabolites include ortho-coumaric acid (7.89) formed directly from coumarin, 3-(2-hydroxyphenyl)-propionic acid (7.91) formed following reduction of coumarin to dihydrocou-... 

Photolytic. Photoproducts reported from the sunlight irradiation of propanil (200 mg/L) in distilled water were 3 -hydroxy-4 -chloropropionanilide, 3 -chloro-4 -hydroxypropionanilide, 3, 4 -di-hydroxypropionanilide, 3 -chloropropionanilide, 4 -chloropropionanilide, propionanilide, 3,4-di-chloroaniline, 3-chloroaniline, propionic acid, propionamide, 3,3, 4,4 -tetrachloroazobenzene, and a dark polymeric humic substance. These products formed by the reductive dechlorination, replacement of chlorine substituents by hydroxyl groups, formation of propionamide, hydrolysis... 

Surprisingly, the partial reduction of quinone 137 is best achieved by refluxing in acetic or propionic acids (yield 67%). Thereby the acids suffer oxidative decarboxylation (82CL701 85BCJ515). Two further unexpected routes are based on the redox reaction with cycloheptatriene (85BCJ2072) and electrolysis under the conditions of the cyclic voltammetry measurements (87BCJ2497), respectively. 

The indirecl reduction by borones consists of two steps addition of a borane across the double bond, and decomposition of the alkylborane by an organic acid, usually propionic acid [341 ... 

Ibuprofen Ibuprofen, 2-(4-iTo-butylphenyl)propionic acid (3.2.23), can be synthesized by various methods [88-98]. The simplest way to synthesize ibuprofen is by the acylation of Mo-butylbenzol by acetyl chloride. The resulting iTo-butylbenzophenone (3.2.21) is reacted with sodium cyanide, giving oxynitrile (3.2.22), which upon reaction with hydroiodic acid in the presence of phosphorus is converted into 2-(4-iTo-butylphenyl)pro-pionic acid (3.2.23), which subsequently undergoes phases of dehydration, reduction, and hydrolysis. 

Beccalli et al. reported a new synthesis of staurosporinone (293) from 3-cyano-3-(lH-indol-3-yl)-2-oxo propionic acid ethyl ester (1464) (790). The reaction of 1464 with ethyl chlorocarbonate and triethylamine afforded the compound 1465, which, on treatment with dimethylamine, led to the corresponding hydroxy derivative 1466. The triflate 1467 was prepared from 1466 by reaction with trifluoromethanesulfonic anhydride (Tf20) in the presence of ethyldiisopropylamine. The palladium(O)-catalyzed cross-coupling of the triflate 1467 with the 3-(tributylstannyl)indole 1468 afforded the vinylindole 1469 in 89% yield. Deprotection of both nitrogen atoms with sodium ethoxide in ethanol to 1470, followed by photocyclization in the presence of iodine as the oxidizing agent provided the indolocarbazole 1471. Finally, reductive cyclization of 1471 with sodium borohydride-cobaltous chloride led to staurosporinone (293) in 40% yield (790) (Scheme 5.248). 

This assumption of Pauly s was confirmed by Knoop and Windaus, who found that histidine is resistant to reduction by sodium and alcohol whereas the pyrimidine rii is very unstable towards this reagent. On reducing Frankel s oxydesaminohistidine, which is obtained from histidine by the action of nitrous acid, they obtained /8-imidazole-propionic acid. This compound was identical with the synthetical product prepared from glyoxylpropionic acid, ammonia and formaldehyde — ... 

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