Undecanoic acids

Undecanoic acid, 32, 104 10-Undecynoic acid, 32, 104 Unsaturation, quantitative estimation by bromate-bromide titration method, 34, 86, 89 Urea, 30, 24 31, 11 Urea, I-(T -bromophenyl)-, 31, 8 1-(o-chlorophenyl)-2-thio-, 31, 21 1,1-dimethyl-, 32, 61 I-(P-phenetyl)-, 31,11... 

Bromine appears at the 10-position on addition of HBr to 10-undecanoic acid or its ethyl ester in benzene if the HBr is introduced under H2, diphenylamine is added as antioxidant, or impurities (aldehydes) that form peroxides in air are previously removed.200,213 However, in presence of peroxides (which may be specifically added or formed from adventitious aldehyde and atmospheric oxygen), radical addition of HBr occurs, leading to 11-bromo-undecanoic acid or its ethyl ester 200 213... 

The first approach involved the amide formation with the 10-undecanoic acid (3) and the diamine 4 to create the monomer 5 which was then polymerized further by metathesis, as shown in Figure 14.6. A second approach to the synthesis of polyamide Nylon involved forming the polymer using the diacid 6, which was polymerized with the aliphatic diamine 4 in the presence of strong bases. Both these methods were able to use the biorenewable starting material and a metathesis step, and both led to the production of the unsaturated PAX, 20 polyamide [39]. Overall, Meier and coworkers found that the synthesis of the diacid first, followed by polymerization with TBD (1,5,7-triazabicyclo[4.4.0]dec-l-ene), was the most efficient route and had some advantages over classical methods, such as avoiding the use of an acid chloride. 

Fig. 1. Treatment of ll-[3 -(benzoyloxy)-17 -oxoestia-l, 3, 5 (10 )-tiien-7 a-yl]undecanoic acid [55592-11-5] (23) in (C4Hg) N with 1. isobutyl...

Figure 15.11 (a) Total ion clnomatogram of a Grob test mixture obtained on an Rtx-1701 column, and (b) re-injection of the entire clnomatogram on to an Rtx-5 column. Peak identification is as follows a, 2,3-butanediol b, decane c, undecane d, 1-octanol e, nonanal f, 2,6-dimethylphenol g, 2-ethylhexanoic acid h, 2,6-dimethylaniline i, decanoic acid methyl ester ], dicyclohexylamine k, undecanoic acid, methyl ester 1, dodecanoic acid, methyl ester. Adapted from Journal of High Resolution Chromatography, 21, M. J. Tomlinson and C. L. Wilkins, Evaluation of a semi-automated multidimensional gas chromatography-infrared-mass specti ometry system for initant analysis , pp. 347-354, 1998, with permission from Wiley-VCH. 

Fig. 14.8. Chromatogram and mass spectrum showing typical GC/MS data. The mass spectrum shown was obtained from the peak indicated with the arrow. Peak identification ldecane, 2 = 1-octanol, 3 = 2,6-dimethylphenol, 4 = 2-ethylhexanoic acid, 5 = 2,3-dimethylaniline, 6 = dodecane, 7 = decanoic acid, methyl ester, 8 = dicyclohexyl amine, 9 = undecanoic acid, methyl ester, 10-dodecanoic acid, methyl ester.

Decene was hydrocarboxylated with a [PdClaj/TPPTS catalyst in acidic aqueous solutions (pH adjusted to 1.8) in the presence of various chemically modified cyclodextrins (Scheme 10.11) [18]. As in most cases, the best results were obtained with DiOMe-P-CD. In an interesting series of reactions 1-decene was hydrocarboxylated in 50 50 mixtures with other compounds. Although all additives decreased somewhat the rate of 1-decene hydroformylation, the order of this inhibitory effect was 1,3,5-trimethylbenzene < cumene < undecanoic acid, which corresponds to the order of the increasing stability of the inclusion complexes of additives with p-CD, at least for 1,3,5-trimethylbenzene (60 M ) and cumene (1200 M ). These results clearly show the possible effect of competition of the various components in the reaction mixture for the cyclodextrin. 

Egyptian mongoose Herpestes ichneumon 2,4,6,10-Tetramethyl 1-undecanoic acid Anal glands Hefetz etal., 1984... 

Testosterone (T.) derivatives for clinical use. T. esters for im. depot injection are T. propionate and T. heptanoate (or enanthate). These are given in oily solution by deep intramuscular injection. Upon diffusion of the ester from the depot, esterases quickly split off the acyl residue, to yield free T. With increasing lipophilicity, esters will tend to remain in the depot, and the duration of action therefore lengthens. A T. ester for oral use is the undecanoate. Owing to the fatty acid nature of undecanoic acid, this ester is absorbed into the lymph, enabling it to bypass the liver and enter, via the thoracic duct, the general circulation. 17-0 Methyltestosterone is effective by the oral route due to its increased metabolic stability, but because of the hepatotoxicity of Cl 7-alkylated androgens (cholestasis, tumors) its use should be avoided. Orally active mesterolone is 1 a-methyl-dihydrotestosterone. Trans-dermal delivery systems for T. are also available. 

Weak acid/strong base titration is used in the pharmacopoeial assays of benzoic acid, citric acid, chlorambucil injection, mustine injection, nicotinic acid tablets and undecanoic acid. 

Undecanoic Acid Heptadecafluoro-2-hydroxy-2H.3H.3H- E10b2, 44 [Oxiran - C(OH)-COOH]... 

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