Abderhalden

Where substances are sufficiently stable, removal of solvent from recrystallised materials presents no problems. The crystals, after filtering at the pump (and perhaps air-drying by suction), are heated in an oven above the boiling point of the solvent (but below this melting point of the crystals), followed by cooling in a desiccator. Where this treatment is inadvisable, it is still often possible to heat to a lower temperature under reduced pressure, for example in an Abderhalden pistol. This device consists of a small chamber which is heated externally by the vapour of a boiling solvent. Inside this chamber, which can be evacuated by a water pump or some other vacuum pump, is... 

Methods for removing water from solids depends on the thermal stability of the solids or the time available. The safest way is to dry in a vacuum desiccator over concentrated sulfuric acid, phosphorus pentoxide, silica gel, calcium chloride, or some other desiccant. Where substances are stable in air and melt above 100°, drying in an air oven may be adequate. In other cases, use of an Abderhalden pistol may be satisfactory. 

Bis-(chloromethyl)durene [3022-16-0] M 231.2, m 197-198 . Crystd three times from benzene, then dried under vacuum in an Abderhalden pistol. 

Methoxynaphthalene [93-04-9] M 158.2, m 73.0-73.6°, b 273°/760mm. Fractionally distd under vacuum. Crystd from absolute EtOH, aqueous EtOH, benzene or n-heptane, and dried under vacuum in an Abderhalden pistol or distd in vacuo. [Kikuchi et al. J Phys Chem 91 574 1987.]... 

Methylnaphthalene [91-57-6] M 142.2, m 34.7-34.9 , b 129-130 /25mm. Fractionally crystd repeatedly from its melt, then fractionally distd under reduced pressure. Crystd from benzene and dried under vacuum in an Abderhalden pistol. Purified via its picrate (m 114-115°) as described for 1-methylnaphthalene. 

Naphthylamine [134-32-7] M 143.2, m 50.8-51.2 , b 160 , pK 3.94. Sublimed at 120° in a stream of nitrogen, then crystd from pet ether (b 60-80°), or abs EtOH then diethyl ether. Dried under vacuum in an Abderhalden pistol. Has also been purified by crystn of its hydrochloride from water, followed by liberation of the free base and distn finally purified by zone melting. CARCINOGEN. 

Nitrophenol [88-75-5] M 139.1, m 44.5-45.5 , pK 7.23. Crystd from EtOH/water, water, EtOH, benzene or MeOH/pet ether (b 70-90°). Can be steam distd. Petrucci and Weygandt [Anal Chem 33 275 1961] crystd from hot water (twice), then EtOH (twice), followed by fractional crystn from the melt (twice), drying over CaCl2 in a vacuum desiccator and then in an Abderhalden drying pistol. 

Phenylanisole (4-methoxybiphenyl) [361-37-6] M 184.2, m 89.9-90.1". Crystd from benzene/pet ether. Dried under vacuum in an Abderhalden pistol. 

A -Phenyl-l-naphthylamine [90-30-2] M 219.3, m 63.7-64.0°, pK j, -0.1. Crystd from EtOH, pet ether or benzene/EtOH. Dried under vacuum in an Abderhalden pistol. 

Tetramethylcyclobutan-l,3-dione [933-52-8] M 140.2, m 114.5-114.9°. Crystd from benzene and dried under vacuum over P2O5 in an Abderhalden pistol. 

Abderhalden pistol. [Das et al. J Chem Soc, Faraday Trans I 78 3485 1982.] HIGHLY POISONOUS and potentially explosive. 

Pringsheim and Merkatz, Z. physiol. Chem. 105, 173 (igig). Abderhalden and Zemplen, ibid. 72, 58 (1911). 

Cyclopropyltriphenylphosphonium Bromide (5). The lactone salt is pyrolyzed by placing it in a round-bottom flask fitted with an adaptor attached to a vacuum source (aspirator is sufficient). The flask is heated (oil bath) to 180-190° for 48 hours. The residue is a virtual quantitative yield of the tan product, which may be crystallized from ethyl acetate giving cream crystals, mp 189-190°. An alternate setup is convenient if a drying pistol (Abderhalden) is available. The compound is placed in the pistol, which is then evacuated. Decalin (bp approx. 187°) is refluxed over the pistol to provide the heating source. The work-up is the same. 

Abderhalden, Fleischmann, and Irion, Fermentforschung 10, 447 (1928). sKosseI, Zeit. physiol. Chcm. 25, 177 (1898) Vickery and Leavenworth, J. Biol. Chem. 78, 627 (1928). 

All analytical and test samples were recrystd from either acet-n-hexane mixts or acetonitrile and dried in an Abderhalden drying app over refluxing nitrobenzene for at least 4 hours. The product was identified as 2,2,2,f,4,4/,4, 6,6,6w-nonanitroter-phenyl by elemental analysis and X-ray molecular wt detn ... 

Reagent 111 was formed by dissolving 0.50 g (3.5 mmol) of II in 25 mL of water in a 50-mL round-bottom flask. To this solution was added 0.15 g (3.61 mmol) of sodium hydroxide, and the mixture was heated on a steam bath for 30 min. The water was removed and the residue suspended in hot toluene. The toluene suspension was filtered and the remaining solid dried in an Abderhalden drying pistol with phosphorus pentoxide. This procedure gave 0.55 g (99%) yield of Reagent 111. 

Phenyl-2(lH)Pyridone Sodiim Salt. A solution of sodium metal (0.25 g, 11.3 mmol) and anhydrous methanol (10 mL) was allowed to react to form sodium methoxide. Pyridone IV (1.88 g, 11 mmol) was added to the solution and allowed to stand at room temperature for 24 h. The methanol was removed under reduced pressure and the residue was extracted with hot benzene 3 times and dried in the Abderhalden drying pistol for 30 min. The yield was 1.7 g (82%). 

Acetyl-2-(i>-ara6i io-tetrahydroxybutyl)-6-methylpyrrole (6 g.) is heated at 80° under diminished pressure over phosphorus pentoxide in an Abderhalden dryer, to constant weight that is, for about three hours. The product is allowed to cool, dissolved in hot ethyl alcohol, and left to crystallize, giving colorless needles m. p., 152°. 

Ab der-Halden A continuous process for distilling coal tar. It is operated under reduced pressure with the heat provided by five, superheated steam. This provides a clean separation of the products, without cracking. Developed in France in the 1920s by C. Ab der-Halden who formed the company PROABD to exploit it. PROABD is now a division of BEFS Technologies, Mulhouse, France, which offers this process and others under the same trade name. Not to be confused with the Abderhalden reaction in biochemistry. 

Almost at the same time Abderhalden (Al) showed the peptide character of the undialyzable part of urine. By means of the Fischer analysis method he isolated from the hydrolyzate of this mixture certain free amino acids, and for the first time introduced the name polypeptide for the analyzed constituent of urine. 

As early as 1905 Abderhalden (Al) isolated from the hydrolyzate of the nondiffusible fraction of human urine four amino acids, i.e., leucine, alanine, glycine, and glutamic acid, and detected two others phenylalanine and aspartic acid. Some amino acids derived from this fraction have been quantitatively determined by Albanese et al. (A3) who found in the amount of the nondiffusible fraction corresponding to one liter of urine as much as 32.8 mg tryptophan, 18.0 mg phenylalanine, 16.2 mg methionine, 15.2 mg cystine, 13.1 mg arginine, 6.7 mg histidine, and 3.9 mg tyrosine. 

Al. Abderhalden, E., and Pregl, F., Uber einen im normalen menschlichen Ham vorkommenden schwer dialyslerbaren Eiweissabkommling. Z. physiol. Chem. 46, 19-23 (1905). 

F. Ehrlich in E. Abderhalden s Handbueh der biologischen Arbeit.smeth-oden IV, Part 2, 2405 (1936) H. Bock in E, Bamann and K. Myrbftck s Die Methoden der Enzymforschung George Thieme Verlag, Leipzig, p. 1914 (1941). 

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