Propionic acid anhydride

Propionyl nitrite (Nitric acid-propionic acid anhydride). CH3.CH2,CO.O.NO raw 103.09 N 13.59% OB to C02 —85.36% golden-yel liq bp <60° (decompn). Prepn is by reacting nitrosyl chloride with Ag propionate... 

Subsequent conversion of dextran derivatives with acetic acid or propionic acid anhydride is an effective method for revealing structural features on the molecular level. This is illustrated on a dextran propionate (Mw 5430 gmol x) which can be completely acetylated with acetic anhydride/pyridine in a separate step yielding a peracetylated sample (dextran propionate acetate, DPA). The assignment of the chemical shifts of DPA is carried out via 2D NMR (Fig. 17). 

A mixture of 5 parts l-(3-cyano-3,3-diphenylpropyl)-4-(2-oxo-l-benzimidazolinyl)piperidine, 7.5 parts propionic acid anhydride and 80 parts benzene is stirred and refluxed for 16 hours. After cooling, the reaction mixture is washed twice with 100 parts water. The aqueous layer is dried over potassium carbonate, filtered and evaporated. The residue is recrystallized from 60 parts of ether, yielding 4 parts crude l-(3-cyano-3,3-diphenylpropyl)-4-(2-oxo-3-propionyl-l-benzimidazolinyl)piperidine. This crop is recrystallized from 20 parts m-methyl-2-pentanone 4-ethyl-2-pentanone, yielding l-(3-... 

The starting materials used by Nicolaou et al. (Scheme 2, above) include 3-pentanone (4), methacrolein, 3-benzyloxypropanal, and propionic acid anhydride, which together account... 

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

PROPIONIC ACID ANHYDRIDE (123-62-6) CgHioOj Combustible liquid. May forms explosive mixture with air [explosion limits in air (vol %) 1.48 to 11.9 flash point 145°F/63°C autoignition temp 545°F/285°C Fire Rating 2]. Reacts... 

PROPIONIC ACID ANHYDRIDE (123-62-6) Combustible liquid (flash point 145°F/ 63°C). Reacts with water, evolving heat and forming propionic acid. Violent reaction with strong oxidizers, strong acids, caustic materials. Incompatible with ammonia, aliphatic amines, alkanolamines, isocyanates, alkylene oxides, epichlorohydrin, nitromethane. 

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. 

Tosyl starch sample (DSjos = 102 0.3 g) was allowed to react with 5 ml (39 mmol) propionic acid anhydride/0.1 g DMAP in 5 ml anhydrous pyridine. The mixture was kept at 20 °C for 20 h and at 80 °C for 5 h. After cooling down to room temperature, the product was isolated by precipitation in 100 ml of ethanol, filtered off, thoroughly washed with ethanol and dried at 50 °C under vacuum. 

Conversion of 6-O-trityl cellulose (see Chapter 4) with acetic acid anhydride or propionic acid anhydride and subsequent detritylation by treating the completely functionalized polymers with HBr in acetic acid yields the... 

Often the chemistry required to synthesize an internal standard is not dissimilar to the derivatization reactions with which the analysis will be familiar. Figure 3 shows examples of the types of reactions that have been used to prepare internal standards in an analytical laboratory. Whenever possible the closest homolog (or analog) should be prepared. The paracetamol homolog was produced by shaking 4-aminophenol hydrochloride with propionic acid anhydride in water until the product... 

To 0.500 mL of the seawater sample (with a boron content of 0-5 mg/L) in the polyethylene beaker add 1.0 mL of glacial acetic acid and 3.0 mL of propionic acid anhydride. Mix by swirling and then add dropwise 0.25 mL of oxalyl chloride and wait at least 15 min for it to cool to room temperature. 

A soln. of 3-propionylamino-6-methyl-2,4-pyronone in propionic acid anhydride refluxed 1 hr. 2-ethyl-6 -methyl-(a-pyrono-3, 4 4,5-oxazole). Y 98%. F. e. s. F.Dallacker, P. Kratzer, and M.Lipp, A. 645, 97 (1961). 

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]. 

W. Reppe and H. Kroper [483] isolated large amounts of propionic acid anhydride in the synthesis of propionic acid from ethylene, carbon monoxide and water. They proved their presumption that ethylene and carbon monoxide react with preformed propionic acid by repeating the experiments with propionic acid as starting material (1). 

Butyric acid anhydride refluxed 4 hrs. with a-propionylpropionic acid mono-fluoroboric acid enolester anhydride complex prepared from propionic acid anhydride and BF3 4-methyl-3,5-octanedione. Y 82%. F. e. s. H. Musso and K. Figge, A. 668, 15 (1963). 

In 2007, Birman et al. showed that BTM (23) could also be used as a powerful desymmetrization agent [53]. Indeed, by subjecting lobelanidine to 20mol% of 23 in the presence of propionic acid anhydride (1.1 equiv.) in CHCI3 at room temperature, the corresponding propionic ester was obtained in quasi-enantiopure form and up to 92% yield. Jones oxidation and subsequent hydrolysis eventually resulted in the isolation of (-)-lobeline, a natural product exhibiting anti-asthmatic, expectorant, and respiratory stimulant activities (Scheme 41.6). 

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