2-Benzyl-succinic acid

The dependence of the glass-transition temperature on the copolymer composition varies with the chemical structure of the comonomer unit. Copolymerization with methyl succinic acid, dimethyl succinic acid, adipic acid, and propanediol results in a decreased glass-transition temperature, whereas copolymerization with benzyl succinic acid and terephthalic acid brings about an increased glass-transition temperature, as shown in Fig. 11. 

Formaldehyde and enantiomeric forms of various p-substitued phenols 7V-tosyl-/-tyrosine (a), 7V-benzoyl-/-tyrosine (b), 7V-p-hydroxyphenylsulfonyl-/-phenylalanine (c), p-hydroxy-benzyl-succinic acid (d), methyl-2-p-hydroxyphenyl-2-succinic acid (e), j3-p-hydroxyphenyl-butyric acid (f) and 7V-methyl, 7V-(p-hydroxybenzyl)-/-menthylamine (g) (XXXIXa-g) were systematically polycondensed both in acidic and basic media. 

A large number of trialkylacetic acid esters have been prepared by mixed Kolbe electrolysis of ethyl malonates [164]. Crossed-coupling is also used for chain extension. Extension by two carbon atoms is achieved with benzyl succinates [153, 180-182], whereby the purification of the chain extended fatty acid is simphfied by using the benzyl half ester [181a]. 

Pharmaceuticals. A wide variety of pyridine compounds, with varying, and often multiple, drug action are used commercially. A few examples are given. A number of antihistamines contain the pyridine moiety in their structure, as exemplified by chlorpheniramine maleate (2-[p-chloro-a-(2-dunethylaminoethyl)benzyl] pyridine acid maleate) doxylamine succinate (2-[cM2-dimethylamino)ethoxy- -methylbenzyl]-pyridine add succinate) and pyrilamine maleate (2-(2-dimethyl-aminoethyl-2-p-methoxybenzyl) aminopyndine acid maleate). These products are synthesized, e.g., from... 

To a solution of 3-N-benzyl-6-carboxamido-3-N-methylamino-l,2,3,4-tetrahydrocarbazole (1.0 g) in ethanol (100 ml) containing succinic acid (0.39 g), Pearlmans catalyst (1.0 g) was added and the mixture shaken under an atmosphere of hydrogen at 45 psi and 50°C for 2 h. The mixture was filtered (celite pad) and the pad washed thoroughly with ethanol. The combined flitrate and washings were evaporated to dryness, coevaporated with ethanol (3 times 100 ml) and recrystallised from methanol to give the (+)-6-carboxamido-3-N-methylamino-l,2,3,4-tetrahydrocarbazole succinate (1 1) salt, melting point 148°-155°C. 

Polymeric electrolytes, polymer-salt complexes, and gelled electrolytes, e.g., benzyl sulfonic acid siloxane, polyethylene oxide (imine, succinate)-LiC104, and PVDF gel in THF containing a mixture of Bu2Mg and AlEtCl2, respectively. 

A mixture of 1.72 g 2-(cyclohexanecarbonylamino)-succinic acid 4-benzyl ester (5.16 mmol), 5 mL pyridine, and 3 mL acetic anhydride was heated at 90 C for 2 h. Excess acid anhydride and pyridine were removed under reduced pressure, and the residue was then diluted with 150 mL ether. The organic phase was then washed successively with 50 mL l.ON HCl and 50 mL water, then dried over solid sodium sulfate, decanted, and concentrated under reduced pressure to yield an oil. The residue was purified by column chromatography (EtOAc/hexanes) to provide 1.16 g 3-(cyclohexanecarbonyl-amino)-4-oxo-pentanoic acid benzyl ester as a pale yellow oil, in a yield of 68%. 

A similar transformation with oxalyl chloride as the reagent and erythro- or threo-2,3-bis-Cbz-diamino-succinic acid monomethyl- or di-4-nitro-benzyl ester as the substrate has been reported [884]. 

With the availability of a bioprocess to produce succinic acid, interest is developing in succinate esters, as plasticizers having a biocomponent studies on a series of succinates have shown that the performance of di-2-ethylhexyl succinate (DEHS) in PVC is very close to that of DEHA except in permanence, where the volatility losses are greater than those of DEHA [29]. If DEHS becomes available at lower prices and if volatile losses are not important, this material may have some utility as a secondary plasticizer. Another type of succinate ester, butyl benzyl succinate, was also evaluated in flexible PVC flooring and shown to perform as both a fast-fusing plasticizer and a stain-resistant plasticizer [30]. 

With succinic acid and some other acids, better results are obtained by reversing the order of addition of the solutions, i.e. by adding the neutralized solution of the acid to the 5-benzyl-thiuronixmi chloride solution. 

Fig. 3.10 Chromatogram of standard acids separated as their benzyl esters on a SE-30 column using temperature programming from 144°C to 257°C at 3°C min then 257°C to 290°C at 5°C min" and isothermal at 290°C. Peak identifications are 1, lactic acid 2, 3-hydroxybutyric acid 3, oxalic acid 4, malonic acid 5, pyruvic benzoxime 6, maleic acid 7, succinic acid 8, fumaric acid 9 glutaric acid 10, malic acid 11, adipic acid 12, 2-oxoglutaric benzoxime 13, oxaloacetic benzoxime. (Redrawn with modifications from Oehlenschlager et al., 1975)...

Methyl, ethyl, n-propyl, isopropyl, n-hutyl, benzyl, cyclohexyl esters of formic, acetic, oxalic, succinic, tartaric, citric, benzoic, salicylic (and other substituted benzoic acids), phthalic and cinnamic acids phenyl esters of acetic, benzoic and salicylic acids. 

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