Diethyl 5- valerate

Thallium diethyl valerate yields" small needles, M.pt. 215° C., which are completely soluble in cold alcohol, ether, pyridine, chloroform, or hot carbon tetrachloride, moderately soluble in cold toluene, acetone, or ethyl acetate, and insoluble in light petroleum. 

Successful results have been obtained (Renfrew and Chaney, 1946) with ethyl formate methyl, ethyl, n-propyl, iso-propyl, n-butyl, iso-butyl, sec.-butyl and iso-amyl acetat ethyleneglycol diacetate ethyl monochloro- and trichloro-acetates methyl, n-propyl, n-octyl and n-dodecyl propionates ethyl butyrate n-butyl and n-amyl valerates ethyl laurate ethyl lactate ethyl acetoacetate diethyl carbonate dimethyl and diethyl oxalates diethyl malonate diethyl adipate di-n-butyl tartrate ethyl phenylacetate methyl and ethyl benzoates methyl and ethyl salicylates diethyl and di-n-butyl phthalates. The method fails for vinyl acetate, ieri.-butyl acetate, n-octadecyl propionate, ethyl and >i-butyl stearate, phenyl, benzyl- and guaicol-acetate, methyl and ethyl cinnamate, diethyl sulphate and ethyl p-aminobenzoate. 

In a 500-ml round-bottom flask fitted with a condenser, and a heating mantle is placed a mixture of 25 g of diethyl 5-(l -carboxy-2 -oxocyclohexyl)valerate, 70 g of barium hydroxide, and 200 ml of methanol, and the mixture is refluxed for 24 hours. After cooling, the mixture is acidified (pH 4) by cautious addition of cold 10% aqueous hydrochloric acid. The acidified solution is saturated with sodium chloride and then extracted three times with 100-ml portions of chloroform. The combined chloroform extracts are dried (anhydrous magnesium sulfate) and evaporated. On vacuum distillation, the residue affords the product (about 15 g), bp 176-17870.5 mm. 

Pentanoic acid (valeric acid). Convert the diethyl propylmalonate into valeric acid, b.p. 183-185 °C, following the procedure described for hexanoic acid. The yield is 75 per cent of theory. 

Replacement of the benzene ring with an -butyl segment has been disclosed Scheme 3.124) [73, 248], Thus, methylation of 5-(A,-tosylamino)valeric acid [250], followed by coupling with diethyl L-glutamate, detosylation, alkylation with (26) HBr and hydrolysis afforded (594). 

NTE was first identified as the presumptive target of neuropathic OP compounds in the initiation of OPIDN (Johnson, 1970). Its activity in cells and tissues is operationally defined as the enzymatic hydrolysis of the non-physiological substrate, phenyl valerate, which is resistant to inhibition by diethyl 4-nitrophenyl phosphate (paraoxon) and sensitive to inhibition by A.A -diisopropylphosphor-odiamidic fluoride (mipafox) under specified conditions of preincubation with inhibitors and subsequent incubation with substrate (Johnson, 1977 Kayyali et al., 1991 Makhaeva et al., 2007). 

Thallium diethyl n hexoate forms transparent needles, half an inch in length, softening at 182° C. and melting at 190° C. except for its solubility in light petroleum, it agrees in all respects with the valerate. 

NTE is an integral membrane protein in neurons and some non-neural cell types of vertebrates [3,27,32] and its activity depends on lipid contents. It is present in all neurons, but is absent from glia [32], NTE can hydrolyze many esters of carboxylic acids. NTE is conveniently detected in vitro by its ability to catalyse OP-sensitive hydrolysis of an artificial substrate, phenyl valerate. Its activity is operationally defined as phenyl valerate hydrolysis resistant to inhibition by 0,0-diethyl-4-nitrophenyl phosphate (paraoxon, non-neuropathic) and sensitive to inhibition by NJ T-diisopropyl phosphorodiamidic fluoride (mipafox, neuropathic), determined under specified conditions [3]. Differential centrifugation of brain homogenates resulted in an enrichment of NTE in microsomal fractions containing elements of endoplasmic reticulum (ER), Goldgi, and plasma membrane [39],... 

Fig. 12. Chromatogram of benzyl esters of C, -C, organic acids obtained using a flame-ionization detector. Column, 3 m X 4 mm I.D. sorbent, 10% SE-130 onChiomosorb W AW DMCS temperature initially 130°C (4.7 min), increased to 150°C at 5°C/min. Peaks 1 = diethyl ether 2 = n-hexanoic acid 3-12 = benzyl esters of the following acids 3 = formic 4 = acetic 5 = propionic 6 = iso-butyric 7 = n-butyric 8 = lactic 9 = isovaleric 10 = -valeric 11 = by-product 12 = n-hexanoic. From ref. 32.

Dr Schupphaus found that propyl and isobutyl alcohols with camphor were active solvents, and the ketones, palmitone, and stearone in alcohol solution, also alpha- and beta-naphthol, with alcohol and anthraquinone (diphenylene diketone) in alcoholic solution, and also iso-valeric aldehyde and its derivatives, amyliden-dimethyl and amyliden-diethyl ethers. 

Benzyl octanoate Benzyl valerate L-Bomeol t-Butyl alcohol Butyl crotonate Butyl isohexanoate n-Butyl mercaptan Butyl octanoate Butyl sorbate Butyraldehyde diethyl acetal... 

Amyl phenylacetate Amyl valerate Amyris (Amyris balsamifera) oil trans-Anethole Anisaldehyde diethyl acetal Anise (Pimpinella anisum) extract p-Anisonitrile Anisyl alcohol o-Anisyl alcohol p-Anisyl isobutyrate Bay (Pimenta acris) oil Benzaldehyde propylene glycol acetal Benzothiazole Benzylacetone 2-Benzylheptanol Benzyl isoamyl ether Benzyl isovalerate Benzyl methyl ether Benzyl octanoate ... 

Cyclohexanone diethyl acetal 2-Ethyl hexyl acetate Ethyl hydroxyheptyl ketone Ethyl octanoate Hexyl butyrate Hexyl Isobutyrate Hydroxycitronellal Isoamyl Isovalerate lsoamyl-2-methylbutyrate Isoamyl valerate Isobutyl hexanoate Isodecanolc acid p-Menthane-8-hydroperoxlde... 

Evaporation of the diethyl ether yields about 180 mg (88%) of pentanoic acid (valeric acid), which may be further purified by microdistillation at reduced pressure (23 mmHg, 96°C) to yield a colourless oil with expected spectroscopic properties. 

Some specific recent applications of the GC-MS technique to various types of polymers include the following PE [49,50], poly(l-octene) [51], poly(l-decene) [51], poly(l-dodecene) [51], 1-octene-l-decene-l-dodecene terpolymer [51], chlorinated polyethylene [52], polyolefins [53, 54], acrylic acid methacrylic acid copolymers [55], polyacrylates [56], styrene-butadiene and other rubbers [57-59], nitrile rubber [60], natural rubbers [61, 62], chlorinated natural rubber [63, 64], polychloroprene [65], PVC [66-68], silicones [69, 70], polycarbonates [71], styrene-isoprene copolymers [72], substituted PS [73], polypropylene carbonate [74], ethylene-vinyl acetate copolymers [75], Nylon [76], polyisopropenyl cyclohexane a-methyl styrene copolymers [77], m-cresol-novolac epoxy resins [78], polymeric flame retardants [79], poly(4-N-alkyl styrenes) [80], polyvinyl pyrrolidone [81], vinyl pyrrolidone-methyl acryloxysilicone copolymers [82], polybutylcyanoacrylate [83], polysulfide copolymers [84], poly(diethyl-2-methacryloxy)ethyl phosphate [85], ethane-carbon monoxide copolymers [86], polyetherimide [87], bisphenol A [88], ethyl styrene [89], styrene-isoprene block copolymer [89], polyvinyl alcohol-co-vinyl acetate [90], epoxide thiol [91], maleic acid-propylene copolymer [92], P-hydroxy butyrate-P-hydroxy valerate copolymer [93], polycaprolactams [39,94], PS [95,96], polypyrrole [95,96], polyhydroxy alkanoates [97], poly(p-chloromethyl) styrene [81], polybenzooxazines and siloxy substituted polyoxadisila-pentanylenes [98,99] poly benzyl methacrylates [100], polyolefin blends after ageing in soil [101] and polystyrene peroxide [43]. 

Chromatogram of 2,4-dinitrophenyl-hydrazones of carbonyl compounds in 25% dimethylformamide/cyclohexane (1) formaldehyde, acetaldehyde, and acrolein, (2) formaldehyde, acetaldehyde, -butyraldehyde, and -valer-aldehyde, (3) -hexylaldehyde and w-dodecylaldehyde, (4) diacetyl (mono-hydrazone), cyclopentanone, cyclohexanone, mixture of methylcyclohe-xanones, (5) fural (trans-derivative), fural (cis-derivative), acetaldehyde, acetone, methyl ethyl ketone, diethyl ketone, and methyl isobutyl ketone. Spots near the start are due to 2,4- dinitrophenylhydrazine. 

Fig. 11.2 Total ion current chromatogram (Varian MAT 44 GC-MS) of organic acids extracted using ethyl acetate and diethyl ether from the urine of a patient with propionic acidaemia and separated as their trimethylsilyl derivatives on a 25 m SE-54 WCOT capillary column using temperature programming from 70°C to 220°C at 4 C min Peak identifications are 1, lactate 2, 3-hydroxypropionate 3, 3-hydroxybutyrate 4, 2-methyl-3-hydroxybutyrate 5, 3-hydroxyisovalerate 6, 3-hydroxy- -valerate 7, aceto-acetate 8 and 9, 2-methyl-3-hydroxyvalerate 10, 3-oxovalerate 11, 2-methyl-3-oxo-valerate (isomer 1) 12,2-methylacetoacetate 13,2-methyl-3-oxovalerate (isomer 2) 14 propionylglycine 15, glutarate 16, adipate 17, 5-hydroxymethyl-2-furoate 18, 2-hydroxyglutarate 19,3-hydroxy-3-methylglutarate 20,4-hydroxyphenylacetate 21 and 22, methylcitrate 23,4-hydroxyphenyl-lactate 24, palmitate. (Redrawn with modifications from Truscott et al., 1979)...

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