2-Cyclohexylpropanoic acid

Cyclohexylpropanoic acid 3-Methylcyclohexanecarboxylic acid ( )-4-Methyl-3-hexenoic acid... 

Men who were exposed to a mist of a specific type of Finnish white spirits used for washing cars (Pfaffli et al. 1985) had elevated levels of dimethylbenzoic acid, a metabolite of trimethylbenzene, in their urine following the workshift. This study attempted to quantify exposure to white spirits through the analysis of dimethylbenzoic acid isomers, which are easily detected markers. It assumed that being in a mixture does not affect the metabolism of trimethylbenzene or any of the other constituents of Stoddard solvent. The amount excreted was linearly related to the estimated exposure level. The composition of the white spirits in this study included 11% aromatics with 1% trimethylbenzene isomers, which is similar to the compositions of Stoddard solvent used in the United States. A correlation between exposure to 1,2,4-trimethylbenzene, a component of white spirits, at the TLV- TWA (25 ppm), and the urinary concentration of 3,4-dimethylhippuric acid (3,4-DMHA) was reported in ceramics workers (Fukaya et al. 1994). Rats were dosed by gavage with t-butylcyclohexane (800 mg/kg), another component of white spirits, and seven compounds were identified as urinary metabolites (Flenningsen et al. 1987). The primary metabolite was trans-4-t-butylcyclohexanol, with lesser amounts of 2 "-hydroxy-4t-butylcyclohexanol, 2-methyl-2-cyclohexylpropanoic acid, 2 "-hydroxy- 4 "-t-butylcyclohexanol, 2-methyl-2-cyclohexy 1-1,3-propanediol, 2-hydroxy-4-butylcyclohexanol, and Cis-4-t- butylcyclohexanol also being detected. Rats that had a white spirit formulation (690.8 mg/kg) applied to their tails 5 days/week for 6 weeks were reported to have excreted several products (dimethylbenzoic acid isomers) of trimethylbenzene metabolism in their urine. 

Cinnamic acid undergoes reactions that are typical of an aromatic carboxyhc acid. Using standard methodology, simple esters are easily prepared and salts are formed upon neutrali2ation with the appropriate base. Hydrogenation of cinnamic acid under mild conditions leads to 3-phenylpropanoic acid [501-52-0] whereas under forcing conditions, such as under high pressure in presence of a nickel catalyst, complete saturation to 3-cyclohexylpropanoic acid [701-97-3] is readily accompHshed (8). 

Such a rearrangement is not observed with glycine, alanine, 2-aminobutanoic acid or 2-amino-3-cyclohexylpropanoic acid, occurs partially with valine and isoleucine, but is complete with phenylalanine, tyrosine and threonine. By analogy with previous dediazoniation studies on 2-amino acids in acidic media,309 this rearrangement has been explained by the anchimeric assistance of alkyl (Val, lie), aryl (f he, Tyr) or hydroxy (Thr) groups during the dediazoniation process 306 for example, in the case of phenylalanine (4). 

With the straight-chain and less sterically hindered carboxylic acids, < 1, such as n-hexanoic, -octanoic, 3-cyclohexylpropanoic, iso-nonanoic and cyclohexanecarboxylic acids, the pHo.5 values go from lanthanum through a minimum to the middle rare earths and then gradually increase through to lutetium. The yttrium behavior in this case is more similar to the lighter lanthanides such as cerium and praseodymium. 

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