Propanoic Acid Anhydride

Figure 10.10 The synthesis of 2R-methylbutanoic acid, illustrating the use of a chiral auxiliary. The chiral auxiliary is 2S-hydroxymethyltetrahydropyrrole, which is readily prepared from the naturally occurring amino acid proline. The chiral auxiliary is reacted with propanoic acid anhydride to form the corresponding amide. Treatment of the amide with lithium diisopropyla-mide (LDA) forms the corresponding enolate (I). The reaction almost exclusively forms the Z-isomer of the enolate, in which the OLi units are well separated and possibly have the configuration shown. The approach of the ethyl iodide is sterically hindered from the top (by the OLi units or Hs) and so alkylation from the lower side of the molecule is preferred. Electrophilic addition to the appropriate enolate is a widely used method for producing the enantiomers of a-alkyl substituted carboxylic acids...

Propionic anhydride (8) Propanoic acid, anhydride (9) (123-62-6) [1S(R),2S]-N-(2-Hydroxy-1-methyl-2-phenylethyl)-N, 2-dimethylbenzene-propionamide (1S,2S)-Pseudoephedrine-(R)-2-methylhydrocinnamide Benzenepropanamide, N-(2-hydroxy-1-methyl-2-phenylethyl)-N, a-dimethyl-,... 

Propionic Anhydride. Propanoic acid anhydride propanoic anhydride methylacetic anhydride. C4H,03 mol wt 130.14. C 55.37%, H 7.75%, O 36.88%. (CH,CH3O0)jO. Obtained by dehydration of the acid or by carbonylation of its esters Reppe, Friederich, U.S. pat 2,730,546 (1956 to Badische Aniltn- Sc. Soda-Fabrik) from propionaldehyde by air oxidation in the presence of cobalt and copper acetate catalysts McFarlane, U.S. pat, 2,491,572 (1949 to Cela-nese). Other syntheses, e.g., from ethanol and carbon monoxide. 

Anhydrid kyseliny propionove BRN 0507066 Caswell No. 708 EINECS 204-638-2 EPA Pesticide Chemical Code 077704 HSDB 1215 Methylacetic anhydride Propanoic acid, anhydride Propanoic anhydride Propionic acid anhydride Propionic anhydride Propionyl oxide UN2496. Liquid mp = -45 bp = 170°, bpi8 = 67.5 d = 1.0110 slightly soluble in CCI4, freely soluble in Et20. 

Propanoic acid, ammonium salt. See Ammonium propionate Propanoic acid anhydride. See Propionic anhydride... 

Synonyms Methylacetic anhydride Propanoic acid anhydride Propanoic anhydride... 

Acid Anhydrides. Symmetrical anhydrides of monocarboxylic acids, when unsubstituted, are named by replacing the word acid by anhydride. Anhydrides of substituted monocarboxylic acids, if symmetrically substituted, are named by prefixing bis- to the name of the acid and replacing the word acid by anhydride. Mixed anhydrides are named by giving in alphabetical order the first part of the names of the two acids followed by the word anhydride, e.g., acetic propionic anhydride or acetic propanoic anhydride. Cyclic anhydrides of polycarboxylic acids, although possessing a... 

Succinic anhydride 211 reacts in the same fashion to produce the l,2,4-oxadiazol-5-yl propanoic acids 212 (Equation 34), which function as excellent substrates for coupling to amino acid derivatives <2000FES719, 1999HC0521, 1999H(51)2961>. 

A similar procedure was applied in the production of 3-(3-aryl-l,2,4-oxadiazol-5-yl)propanoic acids succinic anhydride was used instead of the acid chloride and the yields of these reactions were similar to the previous trials (46-62%). 

Propanethiol Propane-1-Thiol Propane-2-Thiol 1,2,3-Propanetriol Propanoic Acid Propanoic Anhydride... 

Answer IX-c is an unsymmetricai aliphatic anhydride (propanoic 2-cthyl-cyclopentanecarboxylic acid anhydride). 

SYNS METHYLACETIC ANHYDRIDE PROPANOIC ANHYDRIDE PROPIONIC ACID ANHYDRIDE PROPIONYL OXIDE... 

Bis-trifluoromethylmethylene)-1,2,4-thiadioxetane 1,1-dioxide (hexafluoro-isobutenylidene sulfate) (499) is a stable, colorless liquid obtained by treatment of bis(trifluoromethyl) ketene, 3,3,3-trifluoro-2-trifluoromethylpropanoic acid, or the anhydride of the latter with sulfur trioxide. It is said, on the basis of F nmr data, to be in equilibrium with a cyclic, eight-membered dimer (/Teq = 0.1321iter/mole at 34.5°C), analogous to the structure of the above-mentioned methylene sulfate . Hydrolysis of 499 gives 3,3,3-trifluoro-2-trifluoromethyl-propanoic acid. The cyclic sulfate is a powerful donor of sulfur trioxide, as exemplified by its reactions with fluoride, bromide, and iodide ions (but not chloride ions), triethylamine, dioxane, sulfolane, and alkenes (See... 

Nomenclature of Acid Anhydrides Section 13.1 B.2 (a) butanoic anhydride (b) propanoic anhydride ... 

Reactions between 3-halogenopropanoyl chlorides (218) (X = C1 or Br) and sodium, or ammonium, dithiocarbamates (219) produce perhydro-3-alkyl-2-thioxo-l,3-thiazin-4-ones (220) (Equation (29)) <85MI 607-0i>. A similar procedure, leading to 3-acyl-2-hydrazono-5,6-dihydro-l,3-thiazin-4(3/f)-ones (221) (R = Et), requires the treatment of hydrazones (222) with 3-chloro-propanoic acid in the presence of propanoic anhydride containing sodium acetate (Scheme 41). If propanoic anhydride is replaced by succinic anhydride then the acid (221) (R = CH2CH2CO2H) is the product, so it is likely that A-acylation occurs after the heterocycles (223) are formed (Scheme 41) <85MI 607-02>. 

Nitrocoumarin and hydroxylamine in ethanol yield a 1 2 adduct (20) (see Section II,A,3) which with mineral acid cyclizes to 5-nitro-2,3-dihydro-indoxazene-3-acetic acid (63).21 With diazomethane, 63 yields the methyl ester and with acetic anhydride the JV-acetyl derivative. Oxidation to indoxazene-3-carboxylic acid is successful using selenium dioxide, whereas hydrogenation in the presence of palladium-charcoal brings about ring opening to j3-amino-j3-(2-hydroxy-5-nitrophenyl)propanoic acid. 

AI3-28521 EINECS 202-603-6 HSDB 5309 Isobutyric acid anhydride Isobutyric anhydride Isobutyryl anhydride Propanoic acid, 2-methyl-, anhydride UN2530. Liquid mp = -63.5° bp = 183°, bp B89° d = 0,9535 freely soluble in Et20, soluble in CHCI3,... 

Synonyms Isobutyric acid anhydride Isobutyryl anhydride Isobutyryl oxide Isopropylformic anhydride 2-Methylpropanoic acid anhydride 2-Methyl propanoic anhydride 2-Methylpropionic anhydride Empirical CsHuOs... 

Methyl-2-propanethiol. Seet-Butyl mercaptan Methyl propanoate. See Methyl propionate 2-Methylpropanoic acid. Seejsobutyric acid 2-Methylpropanoic acid anhydride. See Isobutyric anhydride... 

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