Pentane acid

Preparation 86.—Racemic Leucine [U cemic,-4k-methyl-2-amino-pentan acid]. 

Preparation 315.—jS-Iodopropionic Acid [Z-Iodo-pentan acid],... 

Normal Caproate 2 Methyl Pentan 4 Acid Methyl 3 Pentan Acid 4 4 Mcthjrl Pentan... 

VALERIANIC ACID n CH,(CH,),COOH (w Propyl acetic acid — Pentane acid) when shaken with water at 16° two layers are formed. 

High vacuum distillation gave a crystalline product, containing small amounts of impurities, inter alia some 2-butynoic acid. Crystallization from a 3 1 mixture of pentane and diethyl ether at low temperature gave the pure acid, m.p. 77°C, in 38-45 yields. 

The extracts were kept below 0°C (note 5). The combined extracts were washed with 5i acetic acid and subsequently dried over magnesium sulfate (note 6). The extract was concentrated in a water-pump vacuum to about 60 ml by means of the rotary evaporator, care being taken that the bath temperature remained below 25°C. The remaining pale yellow solution was warmed to about 35°C (internal temperature). The temperature rose gradually but was kept at about 45°C by occasional cooling. When after about 45 min the exothermic reaction had subsided, the flask was placed in a water-bath at 55°C. After 30 min the remaining pentane was removed in a water--pump vacuum. The orange residue, n 1.5878, yield aa. 92% was almost pure allenic dithioester. 

Addition occurs rapidly in a variety of solvents including pentane benzene dichloro methane chloroform and acetic acid... 

Each isomer has its individual set of physical and chemical properties however, these properties are similar (Table 6). The fundamental chemical reactions for pentanes are sulfonation to form sulfonic acids, chlorination to form chlorides, nitration to form nitropentanes, oxidation to form various compounds, and cracking to form free radicals. Many of these reactions are used to produce intermediates for the manufacture of industrial chemicals. Generally the reactivity increases from a primary to a secondary to a tertiary hydrogen (37). Other properties available but not Hsted are given in equations for heat capacity and viscosity (34), and saturated Hquid density (36). 

Detergents have been manufactured from long-chain alkenes and sulfuhc acid, especially those obtained from shale oil or cracking of petroleum wax. These are sulfated with 90—98 wt % acid at 10—15°C for a 5-min contact time and at an acid—alkene molar ratio of 2 1 (82). Dialkyl sulfate initially forms when 96 wt % acid is added to 1-dodecene at 0°C, but it is subsequently converted to the hydrogen sulfate in 80% yield upon the further addition of sulfuhc acid. The yield can be increased to 90% by using 98 wt % sulfuhc acid and pentane as the solvent at -15°C (83). 

However, for the past 30 years fractional separation has been the basis for most asphalt composition analysis (Fig. 10). The separation methods that have been used divide asphalt into operationally defined fractions. Four types of asphalt separation procedures are now in use ( /) chemical precipitation in which / -pentane separation of asphaltenes is foUowed by chemical precipitation of other fractions with sulfuric acid of increasing concentration (ASTM D2006) (2) solvent fractionation separation of an "asphaltene" fraction by the use of 1-butanol foUowed by dissolution of the 1-butanol solubles in... 

From Boron Halides. Using boron haUdes is not economically desirable because boron haUdes are made from boric acid. However, this method does provide a convenient laboratory synthesis of boric acid esters. The esterification of boron haUdes with alcohol is analogous to the classical conversion of carboxyUc acid haUdes to carboxyUc esters. Simple mixing of the reactants at room temperature or below ia a solvent such as methylene chloride, chloroform, pentane, etc, yields hydrogen haUde and the borate ia high yield. 

The alkylate contains a mixture of isoparaffins, ranging from pentanes to decanes and higher, regardless of the olefins used. The dominant paraffin in the product is 2,2,4-trimethylpentane, also called isooctane. The reaction involves methide-ion transfer and carbenium-ion chain reaction, which is cataly2ed by strong acid. 

Azabicyclo[2.1.0]pentane-3-carboxylic acid antimicrobial activity, 7, 346 l-Azabicyclo[3.3.3]undecane — see Manxine 1 - Aza-2-boracyclohexane, 1 -methyl-synthesis, 1, 647... 

Ethanol with acetic acid, acetone, benzene, chloroform, cyclohexane, dioxane, ethyl ether, pentane, toluene, water or xylene. 

Hydroxy-3-methylbutyric (a-hydroxyisovaleric) acid [600-37-3] M 118.1, m 86°, pK, -3.9. Crystd from ether/pentane. 

Dried with Linde type 5A molecular sieves or Na2S04 and fractionally distd at reduced pressure. Alternatively, it was refluxed with, and distd from, BaO. Also purified by fractional crystn from the melt and distd from zinc dust. Converted to its phosphate (m 135°) or picrate (m 223°), which were purified by crystn and the free base recovered and distd. [Packer, Vaughn and Wong J Am Chem Soc 80 905 1958.] The procedure for purifying via the picrate comprises the addition of quinoline to picric acid dissolved in the minimum volume of 95% EtOH to yield yellow crystals which are washed with EtOH and air dried before recrystn from acetonitrile. The crystals are dissolved in dimethyl sulfoxide (previously dried over 4A molecular sieves) and passed through a basic alumina column, on which picric acid is adsorbed. The free base in the effluent is extracted with n-pentane and distd under vacuum. Traces of solvent are removed by vapour phase chromatography. [Mooman and Anton J Phys Chem 80 2243 1976.]... 

Phenyl acetate [122-79-2] M 136.2, b 78°/10mm, d 1.079, n 1.5039. Freed from phenol and acetic acid by washing (either directly or as a soln in pentane) with aqueous 5% Na2C03, then with saturated aqueous CaCl2, drying with CaS04 or Na2S04, and fractional distn at reduced pressure. 

Ferrocene carboxylic acid [1271-42-7] M 230.1, m 210°(dec), 225-230°(dec). Yellow crystals from pet ether. Also crystd from aqueous ethanol. [Matsue et al. J Am Chem Soc 107 3411 1985.] Acid chloride m 49° crystallises from pentane, Xmax 458nm [J Org Chem 24 280 1959], Methyl ester crystallises from aq MeOH m 70-71°. Anhydride m 143-145° from pet ether [J Org Chem 24 1487 7959]. Amide m 168-170° from CHCl3-Et20 or m 167-169° from C6H6-MeOH. [J Am Chem Soc 77 6295 1955 76 4025 7954.]... 

HCIO4). Refluxed with benzene (6mL/g) in a flask fitted with a Dean and Stark trap until all the water was removed azeotropically (ca 4h). The soln was cooled and diluted with dry pentane (4mL/g of AgC104). The ppted AgC104 was filtered off and dried in a desiccator over P2O5 at 1mm for 24h [Radell, Connolly and Raymond J Am Chem Soc 83 3958 1961]. It has also been recrystallised from perchloric acid. [Caution due to EXPLOSIVE nature in the presence of organic matter.]... 

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