Isobutyl alcohol groups

The amino group is readily dia2oti2ed in aqueous solution, and this reaction forms a basis for the assay of sulfas. Aldehydes also react to form anils, and the yellow product formed with 4-(dimethylamino)hen2a1dehyde can be used for detection in thiu-layer and paper chromatography. Chromatographic retention values have been deterrnined in a number of thiu layer systems, and have been used as an expression of the lipophilic character of sulfonamides (23). These values have corresponded well with Hansch lipophilic parameters determined in an isobutyl alcohol—water system. 

Chemical/Physical. Isobutyl alcohol will not hydrolyze because it does not have a hydrolyzable functional group (Kollig, 1993). 

Because salicylic acid contains the deactivating meta-directing carboxyl group, Friedel-Crafts reactions are generally inhibited. This effect is somewhat offset by the presence of the activating hydroxyl group. Salicylic acid reacts with isobutyl or /-butyl alcohol in 80 wt % sulfuric acid at 75°C to yield 5-/-butylsalicylic acid [16094-31-8], In the case of isobutyl alcohol, the intermediate carbonium ion rearranges to (CH3)3C+. 

Two or more compounds made up of the same number and types of atoms but with different chemical structures are known as isomers. We have already seen the difference between the two isomers -butyl and isobutyl alcohol. These are known as skeletal isomers, since they have different carbon skeletons. There are also positional isomers in which the "functional group" is located at a different position on the carbon skeleton. For example, alpha, beta, and gamma terpineol all have the same arrangement of carbon atoms but with the—OH (hydroxy) group and the double bond in different positions ... 

Treatment of isobutyl alcohol with HBr and H2SO4 at elevated temperatures leads to /-butyl bromide. In the first step, the hydroxyl group is protonated by the sulfuric acid to convert it into a better leaving group, the water molecule. Water then leaves, giving the primary isobutyl carbocation, 4-1. 

Salter (l8 divides the alcohols into three main groups on the basis of their oil/water solubility. Isopropyl alcohol is of the water soluble group, isobutyl alcohol is of the intermediate group, and 2-hexanol is of the oil soluble group. Table IV gives some results for alcohols of each class. No strong effect was seen. We have previously reported (15,) on the ability of alcohols to reduce the viscosity of sodium oleate gels. 

Since the side-chain is an isobutyl group, we must attach an amino acid root to the isobutyl alcohol. This can be accomplished via the phthalimidomalonic ester synthesis ... 

Arts. Refer to Sec. 11.7.1 for the structures and names of the various butyl groups. The common names of alcohols 1(a), 1(b), 11(a), and 11(b) are butyl alcohol, s-butyl alcohol, r-butyl alcohol, and isobutyl alcohol, respectively. 

The an isotropic phase formed at very high NaCl concentrations compared to the first system. Tween 20 has more hydroxyl groups than isobutyl alcohol. Therefore more NaCl was required to get anisotropic phase. At high NaCl concentration, the system divided into two isotropic phases. 

The residue of methyl esters (e.g. from esterification according to procedure 2.1.1 above) is treated with 200 pi of methylene chloride, which is evaporated off to entrain any traces of water. Transesterification is with 100 pi of 1.25 M HCl in isobutyl alcohol at 110 °C for 150 minutes [143]. An essentially similar procedure for making isoamyl esters has also been described [144]. The similar method of transbutylation developed by the Missouri group [145] has been replaced by the direct butyl esterification procedure [146, 147]. 

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