Esterification propionic acid

Reaction of 1-pentanol with propionic acid provides 1-pentyl propionate [624-54-4] a new coatings solvent for automotive refinish and OEM paints, apphances, and for higher-solids systems (37). The esterification of 1-pentanol with formic acid to 1-pentyl formate [638-49-3] is conducted by concomitant removal of by-product water by a2eotropic distillation with diethyl ether (38). 

The ethyl 7-veratrylbutyrate, b.p. 203-207°/20 mm., is obtained in 80% yield by esterification of 7-veratrylbutyric acid by the Fischer-Speier method. The 7-veratrylbutyric acid is prepared by the method of E. L. Martin from /3-(3,4-dimethoxy-benzoyl)-propionic acid. 

Because of the insolubility of cellulose it is not possible to carry out uniform esterification with the lower organic acids (acetic acid, propionic acid etc.) and in those cases where incompletely substituted derivatives are required a two-stage reaction is employed. This involves total esterification in a medium in... 

Esterification of the propionic acid side chain at C-13 (ring C) with a methyl group catalyzed by S-adenosyl-L-methionine-magnesium protoporphyrin 0-meth-yltransferase yields protoporphyrin IX monomethyl ester (MPE), which originates protochlorophyllide by a P-oxidation and cyclization of the methylated propionic side chain. This molecule contains a fifth isocyclic ring (ring E), the cyclopentanone ring that characterizes aU chlorophylls. 

A further example is given in reference [88] Selective esterification of retronecine, the dialcoholic component of a pyrolizidine alkaloid, by the imidazolide method was found to be superior to the acid chloride/pyridine method. Acylation of the 9-position of retronecine with tiglic acid, pivalic acid, isobutyric acid, and propionic acid was investigated concerning the steric requirement of the carboxylic acid. 

By this method, for example, the absolute configurations of the following compounds were established (-)-2-phenylbutyric acid,[48] (-)-hydratropic acid,[48] (+)-0-acetyl-mandelic acid,t48] (-)-2-(7/-carbazolyl)propionic acid,t48] (+)-1 -phenylethanol,[48] (-)-menthol,t48] (+)-1 -phenylethylamine,[48] and 1-alanine ethylester.[48] The determination of the absolute configuration of bacteriochlorophylles c, d and e was made possible by the esterification of the phaeophorbides by CDI to imidazolides.[49]... 

Jso-propyl lactate has been prepared by heating iso-propyl alcohol and lactic acid in a sealed tube at 1700,1 2 and from silver lactate and iso-propyl iodide, together with the iso-propyl ester of a-iso-propoxy-propionic acid.3 Direct esterification of the acid with the alcohol, with sulfuric acid, has failed to give a yield greater than 20 per cent of the theoretical amount, and the product has been less pure. 

The principal competing reactions to ruthenium-catalyzed acetic acid homologation appear to be water-gas shift to C02, hydrocarbon formation (primarily ethane and propane in this case) plus smaller amounts of esterification and the formation of ethyl acetate (see Experimental Section). Unreacted methyl iodide is rarely detected in these crude liquid products. The propionic acid plus higher acid product fractions may be isolated from the used ruthenium catalyst and unreacted acetic acid by distillation in vacuo. 

A few publications dealing with enzymatic conversion using lipases in a chromatographic reactor appeared in the recently literature. Mensah et al. [178] studied the enzymatic esterification of propionic acid and isoamyl alcohol (dissolved in hexane) to produce isoamyl propionate according to the following scheme ... 

Fig. 12. Outlet concentration profiles from a batch chromatographic bioreactor for enzyme catalyzed esterification. Water, which when in the liquid phase irreversibly inhibits the reaction, is adsorbed. The profiles of water (open circle), propionic acid (filled square), isoamyl alcohol (filled triangle) and isoamyl propionate (open square) at the reactor outlet are presented. (Reprinted with permission from [178])...

The second reaction studied using lipase as catalyst was the reversible re-gioselective esterification of propionic acid and 2-ethyl- 1,3-hexanediol [180]. While the previously described reaction was almost irreversible, this reaction is equilibrium limited with an apparent equilibrium constant of 0.6 0.1. In addition, the accumulated water inhibits the enzyme. Therefore, only the removal of the water from the reaction zone assures high enzymatic activity as well as drives the reaction beyond thermodynamic equilibrium. Experiments with two... 

Fig. 13.5 Concentration profiles in the pervaporation-assisted esterification of 1-propanol and propionic acid.

A process performance study has been conducted by David et al. [47] taking the coupling of pervaporation with the esterification reactions of 1-propanol and 2-pro-panol with propionic acid as a model system. Toluene sulfonic acid was appHed as the homogeneous acid catalyst A PVA-based composite membrane from GFT was used. Fig. 13.5 shows the comparison between the esterification reaction with and without pervaporation. Without pervaporation, the conversion factor reaches a hm-it, which corresponds to the equihbrium of the esterification reaction. Coupling of the esterification to pervaporation allows the reaction to reach almost complete conversion. 

It will be shown that Reactions 2 and 3 can be made to proceed at a high rate and with a high selectivity. Combined with simple esterification. Reactions 2 and 3 form a basis for two-step routes for the synthesis of respectively ethyl acetate and propionic acid starting from methanol and synthesis gas as the only feedstock. 

It is known that enantioselectivity of enzymes depends on many different parameters such as temperature, substrate structure, reaction medium, and presence of water. Enantiopreference of enzymes can be greatly affected, even reversed, by changing the reaction solvent. Such an example was reported by Ueji et al. in 1992 for Candida cylindracea lipase-catalyzed esterification of ( )-2-phenoxy propionic acid with 1-butanol [29]. 

Kuppers et al. 133 investigated a similar reaction using a different approach. They investigated the enzymatically catalyzed esterification of propionic acid with... 

The alkylation products are synthetically useful because simple subsequent transformations furnishes precursors of important natural products as illustrated in Scheme 8E.23. Simple oxidative cleavage of allylic phthalimide 45 generates protected (5)-2-aminopimelic acid, whose dipeptide derivatives have shown antibiotic activity. The esterification via deracemization protocol is not limited to the use of bulky pivalic acid. The alkylation with sterically less hindered propionic acid also occurs with high enantioselectivity to give allylic ester 116, which has been utilized as an intermediate towards the antitumor agent phyllanthocin and the insect sex excitant periplanone. Dihydroxylation of the enantiopure allylic sulfone gives diol 117 with complete diastereoselectivity. Upon further transformation, the structurally versatile y-hydroxy-a,(f-un-saturated sulfone 118 is readily obtained enantiomerically pure. 

Low Molecular Weight Acids. The method devised for analyzing free fatty acids will resolve Ci to CB acids as shown in Figure 1, except for formic and propionic acids which are poorly resolved under the conditions used. Propionic acid, however, has been shown to be absent in all mixtures of oxidation products, and thus it presents no problem in this study. Acetophenone, shown in the chromatogram, was a convenient and reliable internal standard for this technique. Detection by thermal conductivity was selected because the flame ionization detector is insensitive to formic acid and, as noted, the high volatility of methyl formate and acetate precludes their quantitative determination by reasonably simple esterification procedures. 

Acrylic acid esters can polymerize readily this must be taken into account during their preparation. Thus, attempts to prepare pentafluorophenyl acrylate from acrylo-yl chloride in the presence of pyridine led to extensive polymerization of the product [24], This polymerization can be prevented by using the less nucleophilic 2,6-dimethylpyridine as base and diethyl ether or pentane instead of THF as solvent (Scheme 7.5). Esterifications of acrylic acid under acidic conditions should be conducted in the presence of small amounts of hydroquinone as radical scavenger. Acrylic acid derivatives can also be prepared by acylation with a propionic acid with a leaving group at C-3 followed by/3-elimination. 

Separately, 72.02 g ethyl 2-(4-isobutylphenyl)-propionate, obtained by the esterification of 2-(4-isobutylphenyl)-propionic acid with ethanol and concentrated H2S04, are solved with 100 ml methanol, this solution is introduced drop by drop into the reaction flask, and stirred and cooled for 5... 

Figure 9.37 Chemical structures of chlorophylls-a and b which contain a propionic acid esterified to a C20 phytol chlorophylls-cj and C2 have an acrylic acid that replaces the propionic acid. Also included are the pheopigments, the four dominant tetrapyrrole derivatives of chloropigments (pheopigments) found in marine and fresh-water/estuarine systems (chlorophyllide, pheophorbide, pheophytin, pyropheophorbide.) More specifically, chlorophyllase-mediated de-esterification reactions (loss of the phytol) of chlorophyll yield chlorophyllides. Pheophytins can be formed when the Mg is lost from the chlorophyll center. Pheophorbides are formed from removal of the Mg from chlorophyllide or removal of the phytol chain from pheophytin, and pyrolyzed pheopigments, such as pyropheophorbide and pyropheophytin, are formed by removal of the methylcarboxylate group (-COOCH3) on the isocylic ring from the C-13 propionic acid group.

Cellulose esters (e.g., cellulose triacetate, cellulose diacetate, cellulose propionate, and cellulose butyrate) are prepared by initially treating cellulose with glacial acetic acid (or propionic acid and butyric acid) followed by the corresponding acid anhydride with a trace of strong acid as a catalyst in chlorinated hydrocarbon. Complete esterification reactions result in the formation of a triester, which undergoes water hydrolysis to form a diester. Cellulose acetate alone or in combination with cellulose triacetate or cellulose butyrate is used as a semipermeable membrane for osmotic pumping tablets, primarily in controlled release systems. The permeability of the membrane can be further modulated by adding water-soluble excipients to the cellulose esters. 

For the esterification of terephthalic acid with ethylene glycol at 473 K, SO /TiCh calcined at 773 K is much more active than SiC -A Ch as shown in Fig. 6 [60]. The SO /TiCh showed a maximum activity when calcined at 573 K for the esterification of oleic acid with glycerol and of propionic acid with butanol at 403 K [61], where the active sites were attributed to Bronsted acid sites from a correlation between the activity and the Bronsted acidity. The esterification of phthalic anhydride with 2-ethylhexanol to form dioctyl phthalate is also efficiently catalyzed by solid super-acids, the selectivity being more than 90% [62]. The... 

A new transesterification stanoxane catalyst, tin (di(chlorodimethylsiloxy)-tin chlor-odimethylsilane), has been used to incorporate ethyl acrylate into the condensation polymer of 2,2-bis(hydroxymethyl)propionic acid. This catalyst is preferable because it allows the reaction to proceed under milder conditions than those using a condensation esterification reaction route and makes it likely for product crosslinking side reactions to occur. 

Aromatic and f-basic features are also linked to a quaternary center in phencyclidine (18, PCP), a well-known drug of abuse.(24) In the MHP test, PCP was not active up to 9 mg/kg sc (higher doses caused ataxia) but its analog 20 proved about twice as effective as morphine.(25) The activity of 20 fell 10-fold after esterification with propionic acid so the compound appears... 

Mensah et al. studied the esterification of propionic acid (P) and isoamyl alcohol (A) to isoamyl propionate and water in the presence of the lipase enzyme [P. Mensah, J. L. Gainer, and G. Carta, Biotechnol. Bioeng., 60 (1998) 434.] The product ester has a pleasant fruity aroma and is used in perfumery and cosmetics. This enzyme-catalyzed reaction is shown below ... 

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