Sodium pimelate

In a little known work, Palaszek examined the conversion of several simple " C-labelled precursors into a-terthienyl in T, erecta 196). These were DL-glucose-UL- C, DL-ornithine-2- C, sodium malonate-2- C, DL-cystine-l- C, DL-serine-3- C, malonic-2- C acid, DL-methionine-2- C, and sodium pimelate-T- C. The dilution factors for the last three were the lowest, 1865, 1385 and 445 respectively. Thus preformed polyacetylenes are not necessarily required. 

Glutarlc acid (n =3), pimelic acid (n = 5) and suberic acid (n = 6) may be obtained from the corresponding dibromides. These are converted by aqueous - alcoholic potas-sium or sodium cyanide into the dinitriles, and this latter are smoothly hydrolysed by 50 per cent, sulphuric acid into the dicarboxybc acids ... 

Pimelic acid. Heat a mixture of 18 g. of pentamethylene dicyanide and 250 g. of 50 per cent, sulphuric acid by weight in a 750 ml. round-bottomed flask under reflux for 9 hours. INIost of the pimehc acid separates from the cold reaction mixture. Filter oflF the crystaUine acid upon a sintered glass funnel. Saturate the filtrate with ammonium sulphate and extract it with three 50 ml. portions of ether. Dissolve the residue on the filter (which is shghtly discoloured, but is fairly pure pimehc acid) in the combined ethereal extracts, dry with anhydrous sodium or magnesium sulphate, and remove the ether by distiUation. Recrystallise the residual sohd acid from benzene containing 5 per cent, of ether. The yield of pure pimehc acid, m.p, 105-106°, is 22 g. 

Sahcyhc acid, upon reaction with amyl alcohol and sodium, reduces to a ring-opened ahphatic dicarboxyhc acid, ie, pimelic acid (eq. 5). The reaction proceeds through the intermediate cyclohexanone-2-carboxyhc acid. This novel reaction involves the fission of the aromatic ring to i j -hexahydrosahcyhc acid when sahcyhc acid is heated to 310°C in an autoclave with strong alkah. Pimelic acid is formed in 35—38% yield and is isolated as the diethyl ester. 

The crude material, which is a mixture of pimelic acid and unchanged salicylic acid, is esterified by boiling for four hours with 260 cc. of absolute ethyl alcohol and 3 cc. of concentrated sulfuric acid. Two-thirds of the alcohol is then removed by distillation. To the residue, 300 cc. of water and 200 cc. of ether are added, the mixture is shaken and the aqueous layer is removed. The ether solution is washed with two 100-cc. portions of 2 N sodium hydroxide solution to remove the ethyl salicylate (Note 7) and then with water until the disappearance of an alkaline reaction. The ether is evaporated and the residue is distilled under reduced pressure. The ethyl pimelate boils at i53-i56°/24 mm. i48-i52°/22 mm. The yield is 27-30 g. (35-38 per cent of the theoretical amount based upon the salicylic acid used). 

Pimelic acid has been prepared as a by-product of the reaction between trimethylene bromide and sodium cyanoacetic ester 1 by the action of carbon dioxide upon pcntamethylene-... 

Ethyl pentadecylate, 16, 37 Ethyl pentanehexacarboxylate, 10, 59 Ethyl phenylacetate, 16, 33 Ethyl -phenylacetoacetate, 18, 36 Ethyl 7-phen ylbut vrate, 18, 25, 26 Ethyl phenylcyanopyruvate, 11, 40 Ethyl (3-phenylethyl ketone, 16, 49 Ethyl phenylmalonate, 16, 33 18, 84 Ethyl phenyloxaloacetate, 16, 33 Ethyl phthalimidomalonate, 14, 58 Ethyl pimelate, 11, 42 17, 91 Ethyl propanetetracarboxylate, 10, 58 Ethyl propionate, 17, 54 Ethyl iso-propylmalonate, 11, 20, 21 Ethyl salicylate, 10, 51 11, 43 Ethyl sebacate, 14, 20 Ethyl sodium phthalimidomalonate, 14, 58... 

The parent compound also undergoes a further ring fission with sodium ethoxide, finally yielding pimelic acid (68).91 Adipic acid is obtained using alkaline hydrogen peroxide.88... 

Pimelic Acid. Hepbnedioic acid 1,5-pentanedi-earboxylic acid. CjHyO mol wt 160.17. C 52.49%, H 7.55%, O 39,96%. HOOC(CHj),COOH. Prepn starting with cyclohexanone and ethyl oxalate Snyder et at.. Org. Syn. coll. vol. II, p 531 (1943) by the action of sodium and isoamyl alcohol on salicylic acid Muller, ibid, p S35. 

The preparation of pimelic acid from a 2-oxocyclohexanecarboxylic ester by an excess of boiling methanolic potassium hydroxide solution is an equally smooth reaction.157 Pimelic acid is also obtained readily by reduction of salicylic acid with sodium and 1-pentanol, doubtless because 2-oxocyclohexanecarboxylic acid is formed as intermediate in the reducing medium 158... 

The Dieckmann condensation is an intramolecular reaction by which cyclic P-keto esters are formed using tethered di-esters under basic conditions. The name derives from its originator, Walter Dieckmann, who first reported the reaction in 1894 and demonstrated the formation of ethyl p-ketocyclopentanecarboxylate from ethyl adipate using sodium base and, in a similar fashion, the formation of p-ketocyclohexanecarboxylate from ethyl pimelate. ... 

By condensing dibromopimelic add and sodium diselenide, Fredga and Styrman [221] reported another add group containing polymer. The add hydrolysis of di(selenocyanato)derivatives of both the roc- and meso-dibromo-pimelic acids also yielded in each case the polymeric diselenide Polymers containing both selenium and sulfur in the backbone have been reported by Bergson et al. [222] ... 

Addition of talc into isotactic polypropylene (PP) induces two types of crystalline forms, i.e., a and forms [89,92,93 ]. Some reported that PP can form 4 different crystalline forms, i.e., a,jS,y,and(5 (smectic) forms [93]).Ferrageetal. [94] showed crystalline onset temperature shift by addition of talc and an a nucleating agent (sodium 2,2 -methyl-bis-(4,6-di-fert-butylphenyl phosphate) in polypropylene. Addition of triphenodithiazine, pimelic acid with calcium stearate, or quinacridone dye permanent red can increase thephase [94 to 96]. 

---