Succinic acid, esterification

Table 1 Summary of succinic acid esterification results.

Esterification. Succinic anhydride reacts readily with alcohols to give monoesters of succinic acid, which are readily esterified to diesters by the usual methods (34—37). 

Succinic acid diesters are also obtained by one-step hydrogenation (over Pd on charcoal) and esterification of maleic anhydride dissolved in alcohols (40) carbonylation of acrylates in the presence of alcohols and Co complex catalysts (41—43) carbonylation of ethylene in alcohol in the presence of Pd or Pd—Cu catalysts (44—50) hydroformylation of acetylene with Mo and W complexes in the presence of butanol (51) and a biochemical process from dextrose/com steep Hquor, using Jinaerobiumspirillum succiniciproducens as a bacterium (52). 

One of the methods used to isolate succinic acid from the waste stream of the adipic acid process is esterification of the mixture of succinic, glutaric, and adipic acid followed by fractionation (65—69). 

Various techniques have been proposed for the recovery of pure succinic acid, including extraction (141—145), selective crystalliza tion (146—151), heating to dehydrate the acid and subsequent recovery of succinic anhydride by distillation (152), esterification foUowed by fractionation of the mixture of the esters (65—69), and separation as urea adduct (118,119). 

A series of experiments was conducted to form monoethyl and diethyl succinate using either sulfuric acid or acidic ion-exchange resin as catalysts. The esterification of succinic acid is modeled as a simple series reaction sequence. 

Succinic acid. Succinic add is also available via fermentation of glucose, and has the potential to become a large-scale industrial chemical in the future. However, there are only a few reports on dehydration reactions involving succinic acids in the literature, and most of these are concerned with esterification to produce dialkyl esters. The synthesis of various dialkyl esters was reported using metal exchanged montmorillonite clays (Na, Mn ", ... 

Figure 85 Esterification reaction of a hydroxyl-containing API and its counterion, succinic acid.

Hydrophobic starches are generated by a variety of reactions, for example by esterification with octenyl-substituted succinic acid anhydride.39 They can have the properties of a polymeric surfactant, which will generate a weak network with dispersed... 

Succinylated Monoglycerides occur as waxy solids having an off white color. They are a mixture of succinic acid esters of mono- and diglycerides produced by the succinylation of a product obtained by the glycerolysis of edible fats and oils, or by the direct esterification of glycerol with edible fatforming fatty acids. They melt at about 60°. They are soluble in warm methanol, in ethanol, and in n-propanol. 

Water solubility can be greatly improved by the standard ploy of esterification with succinic acid and conversion to the sodium salt. Applied to compound (155), this technique gives sodium artesunate (158), a water-soluble prodrug that may be given intravenously (196). It may be assumed that hydrolysis occurs in vivo to give back (155) as the active antimalarial because (156) has been shown to be unstable in aqueous solution and because analogous carboxylic acids with a nonhydro-lyzable ether link are relatively inactive. 

Mares et al. [52] recently concluded that hydrogen-ion catalysis during this esterification was not likely and that catalysis by undissociated acid occurred together with a reaction in which, kinetically at least, no form of catalysis was involved. On the other hand, Vansco-Szmercsanyi et al. [53] concluded that polyesterification of maleic, fumaric and succinic acids with ethylene glycol or 1,2-propylene glycol was catalysed by protons. Much work clearly remains to be done on defining the detailed mechanism of catalysis by the acidic species during esterifications. 

They are both chrysanthemic acid esters of (5-benzylfuran-3-yl)methanol (Elliott alcohol, 1) [15]. Patented methods [16] for the industrial preparation of Elliotf s alcohol are demanding or such as to be hardly exploited in industrial-scale plants. For instance, in one of these methods [17] (5-benzyl-3-furyl)methanol is obtained by a sequence of Claisen condensation of benzyl cyanide and a dialkyl succinate, hydrolysis, esterification, protection of the ketone group, formylation, cyclization to 5-benzyl-3-furfuryl ester and reduction to alcohol with lithium aluminium hydride. 

Esterification of hydroxylic functions with polyacids (e.g. succinic acid, phosphoric acid) represents an excellent way to prepare water-soluble prodrugs (see Chapter 38)... 

Treating starch phosphates with chlorine in methanol increased their viscosity.1606,1607 A viscous, semitransparent paste was obtained using com starch for simultaneous esterification of phosphoric acid and succinic acid in the presence of urea.1608 Polyphosphoric acid was also used, together with calcium carbonate and hydroxide as well as borax.1609... 

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