Valeric acids

Valeric acid Pentanoic acid CH3(CH2)3C00H Valerian... 

In the light or medium cuts, the acids are linear as in valeric acid CHg - (CH2)3 - COOH or stearic acid CHg - (CH2)ig - COOH. 

CHjIjCHCHjsCOOH MO Valeric acid (+ (CH3),CHCH2C00CH2CH2CH(CH3),) MoAmyl ioovalerate... 

The gas is dried by passage through wash bottles containing concentrated sulphuric acid. Alternatively and more simply, the technique (described below for n.valeric acid) utilising solid carbon dioxide (Dry Ice or Drikold) may be employed. 

Alternatively, the solution of the Grignard reagent may be poured on to solid carbon dioxide (Dry Ice)—for experimental details, see under n-Valeric Acid, Section 111,84. 

MO-Valeric acid is converted by phosphorus and bromine into a-bromo-tso-valeryl bromide the latter upon beating with urea gives bromural ... 

Equip a 1 litre bolt-head flask with dropi)ing fuuncl and a double surface reflux condenser to the top of the latter attach a device (e.g.. Fig. II, 8, 1. c) for the absorption of the hydrogen bromide evolved. Place 100 g. (108 ml.) of dry iso-valeric acid (Section 111,80) and 12 g. of pmified red phosphorus (Section 11,50,5) in the flask. Add 255 g. (82 ml.) of dry bromine (Section 11,49,5) slowly through the dropping funnel at such a rate that little or no bromine is lost with the hydrogen bromide evolved the addition occupies 2-3 hours. Warm the reaction mixture on a water bath until the evolution of hydrogen bromide is complete and the colour of the bromine has disappeared. Pour off the liquid reaction product into a Claisen flask and distil mider the reduced pressure of a water pump. Collect the a-bromo-wo-valeryl bromide at 117-122°/25-30 mm. The yield is 150 g. 

It IS hard to find a class of compounds in which the common names of its members have influenced organic nomenclature more than carboxylic acids Not only are the common names of carboxylic acids themselves abundant and widely used but the names of many other compounds are derived from them Benzene took its name from benzoic acid and propane from propionic acid not the other way around The name butane comes from butyric acid present m rancid butter The common names of most aldehydes are derived from the common names of carboxylic acids—valeraldehyde from valeric acid for exam pie Many carboxylic acids are better known by common names than by their systematic ones and the framers of the lUPAC rules have taken a liberal view toward accepting these common names as permissible alternatives to the systematic ones Table 19 1 lists both common and systematic names for a number of important carboxylic acids... 

At 101.3 kPa at 1 atm. Calculated as valeric acid. Calculated as acetic acid. 

Cellulose valerates have been synthesized by conventional methods using valeric anhydride and sulfuric acid catalyst (25,26). Alternatively, the cellulose is activated by soaking in water, which is then displaced by methylene chloride or valeric acid the temperature is maintained at <38° C to minimize degradation. 

Esters of medium volatility are capable of removing the water formed by distillation. Examples are propyl, butyl, and amyl formates, ethyl, propyl, butyl, and amyl acetates, and the methyl and ethyl esters of propionic, butyric, and valeric acids. In some cases, ternary azeotropic mixtures of alcohol, ester, and water are formed. This group is capable of further subdivision with ethyl acetate, all of the ester is removed as a vapor mixture with alcohol and part of the water, while the balance of the water accumulates in the system. With butyl acetate, on the other hand, all of the water formed is removed overhead with part of the ester and alcohol, and the balance of the ester accumulates as a high boiler in the system. 

FIG. 13-65 Valeric acid-water separation with formic acid, (a) Mass balances on distillation region diagram, (h) Conceptual sequence. 

METHYL B-BROMOVALERATE (Valeric acid, 8-bromo-, methyl ester)... 

Amino-n-valeric acid hydrochloride [627-95-2] M 153.6, m 103-104 . Crystd from CHCI3. 

Valeric acid (n-pentanoic acid) [109-52-4] M 102.1, b 95 /22mm, 186.4 /atm, d 0.938, n 1.4080, pK 4.81. Water was removed from the acid by distn using a Vigreux column, until the boiling point reached 183 . A few crystals of KMn04 were added, and after refluxing, the distn was continued, [Andrews and Keefer 7 Am Chem Soc 83 3708 1961.]... 

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