Dodecanoic acid

The telomer 137, obtained by the reaction of butadiene with malonate, is a suitable compound for the syntheses of naturally occurring dodecanoic acid derivatives, such as queen substance (I38)[l 7], one of the royal jelly acids (139)[I18], and pellitorine fl40)[ll9]. 

Dodecanoic acid Tetradecanoic acid Hexadecanoic acid Octadecanoic acid Icosanoic acid... 

Nylon-6,9, Nylon-6,10, and Nylon-6,12. These nylons are all produced from hexamethylenediamine and either azelaic, sebacic, or dodecanoic acid. They are produced by a process similar to that for nylon-6,6, usually using batch autoclaves. 

The polyamide copolymer of dodecanoic acid with methylenedi(cyclohexylamine) (MDCHA, PACM) was sold as continuous filament yam fiber under the tradename QIANA. As late as 1981, over 145,000 t was produced using high percentages, typically 80%, of trans, trans MDCHA isomer. The low melting raffinate coproduct left after t,t isomer separation by fractional crystallisation was phosgenated to produce a Hquid aUphatic diisocyanate marketed by Du Pont as Hylene W. Upon terrnination of their QIANA commitment, Du Pont sold the urethane intermediate product rights to Mobay, who now markets the 20% trans, trans—50% cis, trans—30% cis, cis diisocyanate isomer mixture as Desmodur W. In addition to its use in polyamides and as an isocyanate precursor, methylenedi (cyclohexyl amine) is used directiy as an epoxy curative. The Hquid diamine mixture identified historically as PACM-20 is marketed as AMICURE PACM by Anchor Chemical for performance epoxies. 

Resolution of racemic alcohols by acylation (Table 6) is as popular as that by hydrolysis. Because of the simplicity of reactions ia nonaqueous media, acylation routes are often preferred. As ia hydrolytic reactions, selectivity of esterification may depend on the stmcture of the acylatiag agent. Whereas Candida glindracea Upase-catalyzed acylation of racemic-cx-methylhenzyl alcohol [98-85-1] (59) with butyric acid has an enantiomeric value E of 20, acylation with dodecanoic acid increases the E value to 46 (16). Not only acids but also anhydrides are used as acylatiag agents. Pseudomonasfl. Upase (PFL), for example, catalyzed acylation of a-phenethanol [98-85-1] (59) with acetic anhydride ia 42% yield and 92% selectivity (74). 

Sodium dodecanoate (sodium laurate) [629-25-4] M 222.3, pK 5.3 (-COOH). Neutralised by adding a slight excess of dodecanoic acid, removing it by ether extraction. The salt is recrystd from aq soln by adding pure Me2CO and repeating the process (see sodium decanoate on p. 468). Also recrystd from MeOH. 

Figure 15.7 Cliromatographic separation of cliiral hydroxy acids from Pseudomonas aeruginosa without (a) and with (h) co-injection of racemic standards. Peak identification is as follows 1, 3-hydroxy decanoic acid, methyl ester 2, 3-hydroxy dodecanoic acid, methyl ester 3, 2-hydroxy dodecanoic acid, methyl ester. Adapted from Journal of High Resolution Chromatography, 18, A. Kaunzinger et al., Stereo differentiation and simultaneous analysis of 2- and 3-hydroxyalkanoic acids from hiomemhranes hy multidimensional gas cliromatog-raphy , pp. 191 -193, 1995, with permission from Wiley-VCH. (continuedp. 419)...

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. 

Lipase CA also polymerized hydrophobic oxyacids efficiently. The DP value was beyond 100 in the polymerization of 16-hydroxyhexadecanoic acid, 12-hydroxy dodecanoic acid, or 10-hydroxy decanoic acid under vacuum at high temperature (90°C) for 24 h, whereas the polyester with lower molecular weight was formed from 6-hydroxyhexanoic acid under similar reaction conditions. This difference may be due to the lipase-substrate interachon. 

FIGURE 2.6 Concentration profiles of (a) hexadecanoic acid, sample concentration C = 0.025 mol 1 , (b) dodecanoic acid, sample concentration C = 0.1 mol 1" , obtained on microcrystalline cellulose with decaline as mobile phase [20]. 

The following experimental results are presented on the use of solid acid catalysts in esterification of dodecanoic acid with 2-ethylhexanol and methanol. In the next figures, conversion is defined as X [%] = 100-(1 - [Acid]fi ai / [Acid]Muai), and the amount of catalyst used is normahzed cat [%] - 100-A/cat / (A/acid + Milcohol)-Several alcohols were used to show the range of apphcability. The selectivity was assessed by testing the formation of side products in a suspension of catalyst in alcohol. Under the reaction conditions, no products were detected by GC analysis. 

Figure 33.1. Esterification of dodecanoic acid with 2-ethylhexanol (left) non-catalysed and catalysed (0.5-5 wt% SZ catalyst) reaction profiles (right).

Figure 33.2. Esterification of dodecanoic acid with methanol, using an alcohokacid ratio of 3 1 and sulfated zirconia (SZ) as catalyst.

The experimental results are presented for the esterification of dodecanoic acid (C12H24O2) with 2-ethylhexanol (CgHigO) and methanol (CH4O), in presence of solid acid catalysts (SAC). Reactions were performed using a system of six parallel reactors (Omni-Reacto Station 6100). In a typical reaction 1 eq of dodecanoic acid and 1 eq of 2-ethylhexanol were reacted at 160°C in the presence of 1 wt% SAC. Reaction progress was monitored by gas chromatography (GC). GC analysis was performed using an InterScience GC-8000 with a DB-1 capillary colunm (30 m x 0.21 mm). GC conditions isotherm at 40°C (2 ntin), ramp at 20°C min to 200°C, isotherm at 200°C (4 min). Injector and detector temperatures were set at 240°C. 

Chemicals and catalysts - Double distilled water was used in all experiments. Unless otherwise noted, chemicals were purchased from commercial companies and were used as received. Dodecanoic acid 98 wt% (GC), methanol, propanol and 2-ethylhexanol 99+ wt% were supplied by Aldrich, niobic acid by Companhia Brasileira de Metalurgia e Mineragao (CBMM), zirconil chloride octahydrate 98+ wt% by Acros Orgartics, 25 wt% NH3 solution and H2SO4 97% from Merck. Zeolites beta, Y and H-ZSM-5 were provided by Zeolyst, and ion-exchange resins by Alfa. 

The colvooi efficiency is determined by the separation number tained for the methyl esters of decanoic, undecanoic, and dodecanoic acids (E o> 12> A relative difference in the molecular sizes of the homologous pairs decreases with increasing molecular size, the first pair of methyl esters (E, /E t) provides a separation number value that is about 8% higher than that of the... 

Salmi T, Paatero E and Fagerstolt K (1993b) Optimal Degree of Backmixing in Autocatalytic Reactions A Case Study Chlorination of Dodecanoic Acid, Chem Eng Res Des, 71 531-542. 

Unlike the crystalline cycloamylose complexes, combining ratios of host to guest in solution are usually 1 1. A notable exception is the interaction of the cycloamyloses with long chain aliphatic carboxylic acids. Solubility plots suggest that as many as four cycloheptaamylose molecules may interact with a single molecule of dodecanoic acid (Schlenk and Sand, 1961). In analogy to the crystalline state, cycloamyloses may form channels in solution in order to accomodate extended chains. 

The submitters employed a sample of dodecanoic acid, m.p. 42.5-43°, obtained by fractional distillation of commercial material. The checkers used Eastman Kodak Company yellow-label-grade dodecanoic acid, m.p. 44.5-45°. If a product free of homologous material is desired, purified dodecanoic acid should be used as starting material. 

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