D-2- -propionic acid

Fig. 8.5. HPLC chromatogram of a first-out silage juice using a Rezex ROA-organic acid column. Identity a, laotio aoid b, formic acid c, acetic acid d, propionic acid e, n-butyric acid f, 2-ethylbutyric acid (internal standard).

FIGURE 9.1 Temperature dependence of the storage and loss moduli of chitosan films with the indicated draw ratios. The films were heat-treated at 120°C for 2h. Solvents were (a) acetic acid, (b) formic acid, (c) butyric acid, and (d) propionic acid. 

Nucleophilic replacement reactions (by AcS, Ph CO S , MeS , and PhCHaS") with methyl 0-toluene-p-sulphonyl-L-lactate and sodium L-2-chloropropionate give 2-acylthio- and 2-alkylthio-D-propionic acids and esters. Extensive racemization accompanies the use of excess thio-acetate or thiobenzoate, due to further 5 2 replacement reactions, as observed for LiAlH4 reduction of L-(2-methylthio)propionic acid or its methyl ester. Diborane reduction gives optically pure L-(2-methylthio)-propanol, however. This work includes a new synthesis of ( + )-2-mercaptopropionic acid, though by known methods, and establishes the D configuration for this isomer. 

By contrast, in the system propionic acid d) - methyl isobutyl ketone (2), (fi and are very much different when y 1, Propionic acid has a strong tendency to dimerize with itself and only a weak tendency to dimerize with ketone also,the ketone has only a weak tendency to dimerize with itself. At acid-rich compositions, therefore, many acid molecules have dimerized but most ketone molecules are monomers. Acid-acid dimerization lowers the fugacity of acid and thus is well below unity. Because of acid-acid dimerization, the true mole fraction of ketone is signi-... 

Dichlorophenols. Among all the dichlorophenols, C H Cl O, it is 2,4-dichlorophenol that is produced in greatest quantity. 2,4-Dichlorophenol is used in manufacturing 2,4-dichlorophenoxyacetic acid [94-75-7] (2,4-D) and 2-(2,4-dichlorophenoxy)propionic acid [720-36-5] (2,4-DP). Industrially, 2,4-dichlorophenol can be obtained by chlorinating phenol, -chlorophenol, o-chlorophenol, or a mixture of these compounds in cast-iron reactors. The chlorinating agent may be chlorine or sulfuryl chloride in combination with a Lewis acid. For example ... 

Propionic acid [79-09-4] M 74.1, b 141 , d 0.992, n 1.3865, n25 1.3843, pK 5-6.8 (Ho scale, aq H2SO4), pK2 4.88. Dried with Na2S04 or by fractional distn, then redistd after refluxing with a few crystals of KMn04. An alternative purification uses the conversion to the ethyl ester, fractional distn and hydrolysis. [Bradbury J Am Chem Soc 74 2709 1952.] Propionic acid can also be heated for 0.5h with an amount of benzoic anhydride equivalent to the amount of water present (in the presence of Cr03 as catalyst), followed by fractional distn. [Cham and Israel 7 C/iem 5oc 96 I960.]... 

This was transformed into the quaternary d-bromocamphorsulphonate, m.p. 265°, but no resolution has yet been effected. The lactam of 3-carboxyhexahydrocarbazole-1 ll-)3 8 -dipropionic acid (XXIV, with a carboxyl group at C ), CigH jO N, rn.p. 257-8°, has also been prepared. The same authors, with Holmes, have synthesised the lactam of 11-ethylhexahydrocarbazole-l-)3-propionic acid, Ci,H3iON, m.p. 106-8-107-5°, of which (XXrV) is a carboxy-derivative. 

The successful labeling of the elusive 14a-position in cholestane represents a very important application of this reaction.It is known that hydroboration of the double bond in 5of-cholest-14-ene (174) occurs on the a-side. Consequently, by using deuteriodiborane (generated by the reaction of boron trifluoride etherate with lithium aluminum deuteride) and then propionic acid for hydrolysis of the alkylborane intermediate, 14a-d,-5a-cholestane (175) is obtained in 90% isotopic purity. This method also provides a facile route to the C-15 labeled analog (176) when the alkylborane derived from 5a-cholest-14-ene is hydrolyzed with propionic acid-OD. ... 

Chemical Name (+)-6-methoxy-a-methyl-2-naphthaleneacetic acid Common Name d-2-(6-methoxy-2-naphthyl)propionic acid Structural Formula ... 

Najfpour, G.D., Propionic and Acetic Acid Fermentation using Propionibacterium acidipropionici in Batch and Continuous Culture , Ph.D. thesis, University of Arkansas, Fayetteville, AR, 1983. 

C2Hs.C02.CH2.CH2,N02 mw 147,15 N 9.52% OB to C02 -114.15% colorl mobile liq mp, when distd above 150° the compd deton bp 106.0 to 108.2° at 10mm d 1.1727g/cc RI 1.4336. Prepn is by reacting at a boil 2-nitro-ethylalcohol with propionic acid in benz solvent, with coned sulfuric acid as the coupling reagent. The prod is recovered by vac distn Ref Beil 2, 524 ... 

Abbreviations N-methyl-D-aspartate (NMDA), alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA), L(+)-2 amino-3-phosphonopropionic acid (L-AP3), 6-cyano-7-nitroqninoxaline (CNQ5Q, 2,3-dihydroxy-6-nitro-7-sulfamyl-benzo-f-quinoxaline (NBQX), 3-(2-carboxypiperazin-4-yl)-propyl-l-phosphonic acid (CPP), 7 Chlorokynnreic... 

Casanola-Martin GM et al. (2006) New tyrosinase inhibitors selected by atomic linear indices-based classification models. Bioorg Med Chem Lett 16(2) 324-330 Tan CY, Wainman D, Weaver DF (2003) N-, alpha-, and beta-substituted 3-amino-propionic acids design, syntheses and antiseizure activities. Bioorg Med Chem 11(1) 113-121... 

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. 

By this method, for example, the absolute configurations of the following compounds were established (-)-2-phenylbutyric acid,[48] (-)-hydratropic acid,[48] (+)-0-acetyl-mandelic acid,t48] (-)-2-(7/-carbazolyl)propionic acid,t48] (+)-1 -phenylethanol,[48] (-)-menthol,t48] (+)-1 -phenylethylamine,[48] and 1-alanine ethylester.[48] The determination of the absolute configuration of bacteriochlorophylles c, d and e was made possible by the esterification of the phaeophorbides by CDI to imidazolides.[49]... 

Zmijewski, M., Gillespie, T.A., Jackson, D.A. etal. (2006) Application of biocatalysis to drug metabolism preparation of mammalian metabolites of a biaryl-bis-sulfonamide AMPA (a-amino-3-hydroxy-5-methylisoxazole-4-propionic acid) receptor potentiator using Actinoplanes missouriensis. Drug Metabolism and Disposition The Biological Fate of Chemicals, 34, 925—931. 

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. 

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