Buchner synthesis

The residue of crystalline putrescine dihydrochloride is rinsed onto a Buchner funnel with the aid of 100-200 ml. of absolute ethanol used in several portions. The last portions of ethanol are used as wash liquid for the crystals. The crystals are finally pressed dry and washed with 25 ml. of ether. The air-dried product weighs 53-55 g. (72-74%) and melts above 275. Analysis for chlorine indicates that the salt is anhydrous. Concentration of the filtrate to a volume of about 25 ml. yields an additional 1-2 g. total yield 73-77%. The entire synthesis may be completed in one day. 

Bubbly liquid, structure of, 12 7 Buccal drug dehvery, 9 48 Bucherer reaction, 9 279 Bucherer synthesis, 2 571 Buchner, Edward, 11 8 Buckingham s theorem, 3 589 Buckingham Pi theorem, 11 744 Buckminsterfullerene (Ceo), 22 719 photovoltaic effects in, 22 220 Buckminsterfullerenes, 4 735 12 228. 

The decomposition of these latter esters at high temperatures constitutes the important synthesis of cyclo-propane derivatives (Buchner) ... 

Wohler s preparation of urea from ammonium cyanate, which could in principle be derived totally from inorganic constituents, is cited as an early demonstration (1828) that living cells were not obligatorily required for the synthesis of natural products. I can prepare urea without requiring a kidney or an animal—either man or dog. Three years after the death of Pasteur the finding by Hans and Edouard Buchner (1897) that fermentation still occured in a cell-free extract from yeast and so did not require the presence of organized cells, was virtually the final nail in the coffin for vitalism and an essential preliminary to the study of intermediary metabolism (Chapter 4). 

B. N,N,N-Trimethylcyclooclylammonium hydroxide. To a 1-1. round-bottomed flask equipped with a stirrer are added 100 g. (0.34 mole) of N,N,N-trimethylcyclooctylammonium iodide, 76 g. of silver oxide (Note 6), and 35 ml. of distilled water. The suspension is stirred at room temperature for 5 hours and is filtered through a Buchner funnel. The filter cake is washed with four 35-ml. portions of distilled water. The light yellow filtrate is transferred to a 1-1. round-bottomed flask and the volume is reduced to approximately 90 ml. employing a rotary evaporator and a 40° water bath. The viscous N,N,N-trimethyl-cyclooctylammonium hydroxide solution is transferred (Note 7) to a 200-ml. dropping funnel, with a pressure-equalizing side arm, for use in the next step in the synthesis (Note 8). 

The active principle was shown to be salicin by Buchner in 1828 but the bitter taste and damage to the gastric mucosa limited its use. Piria isolated salicylic acid from salicin in 1838. In 1859, Kolbe discovered the structure and synthesis of salicylic acid and in 1897 acetylsalicylic acid was synthesized by Hoffmann. Two years later, in 1899, acetylsalecylic acid, the first nonsteroidal antiinflammatory drug was registered under the name Aspirin (Fig. 2). 

Mesoporous silica spheres were synthesized under the catalyst of ammonia in the mixed water-DMF solvent. In typical synthesis, 0.8 g (2.2 mmol) CTAB was heated slightly to allow it dissolved in the mixed solvent of 19.0 g (1.06 mol) water and 19.0 g (0.26 mol) DMF. After cooling to room temperature, 1.0 g (15 mmol) ammonia and 2.08 g (10 mmol) TEOS were added to the mixture with an electromagnetic stirrer and the stirring rate was kept about 480 rpm. After stirring for 16 to 25 h, the white solid product was Filtered on a Buchner funnel and allowed to dry in air at room temperature. The dried precipitate was immersed into highly diluted aqueous ammonia (pH 10) and kept at 100 °C for 2 days, the product was washed with distilled water and dried at room temperature in air. Then the product was calcined at 550 °C for 4h to remove the templates. 

BUCHNER, EDUARD (1860—1917). A German chemist who was awarded the Nobel prize for chemistry in 1907. His works included the synthesis of diiodoacelamid through alcoholic fermentation caused by enzymes, as well as the discovery of zymase, die first enzyme to be isolated. He received his Ph.D. at the University of Munich, where he became a lecturer. Later, he taught and performed research at Tubingen, Berlin, and Wiirzburg. 

A 3 per cent solution of hydrazoic acid (synthesis 26A) is neutralized with an aqueous solution of pure potassium hydroxide. The resulting solution of potassium azide is concentrated on the steam bath to incipient crystallization. The solution is then made slightly acid with hydrazoic acid to replace the hydrogen azide lost by hydrolysis. A volume of ethyl alcohol twice that of the solution is added, and the solution is cooled in an ice bath. Since the solubility in alcohol of the alkali and alkaline earth azides is very slight (see table below), precipitation in the form of a white microcrystalline salt takes place readily. From 90 to 95 per cent recovery of the theoretical quantity of potassium azide can be effected. The precipitated azide is filtered on a Buchner funnel and washed with cold absolute alcohol and then with ether. Any traces of adhering solvent may be removed in a vacuum desiccator. In a typical run, 300 ml. of a solution of hydrazoic acid containing 8.5 g. of HN3 was neutralized with potassium hydroxide, and the isolation of potassium azide effected as indicated above. Yield 14.7 g. (91.5 per cent) KN3. 

To a solution of 2,3-butanedione dioxime (23.2 g, 0.2 mole) in 500 mL of boiling 95% ethanol in a 2-L Erlenmeyer flask is added a solution of cobalt(II) nitrate hexahydrate (29.0 g, 0.10 mole) in 500 mL of hot 95% ethanol. The red-brown solution is boiled on a hot plate for 5 minutes and then a solution of sodium bromide (15.8 g, 0.15 mole) in water (20 mL) is added. The brown solution is allowed to cool to 35°. Dimethyl sulfide (11 mL, 0.15 mole) is added, and the resulting solution is stirred vigorously for 8 hours with the flask open to the atmosphere. During the stirring a brown solid precipitates from solution. The solid is collected by suction filtration on a Buchner funnel and washed successively with 200-mL portions of water, ethanol, and diethyl ether. The fine, dark-brown crystals are air dried and dissolved in dichloromethane and the system is filtered. The filtrate is evaporated to give typically 20 g of product (yield is about 50%). Its purity, as it is isolated in the above procedure, is adequate for subsequent procedures of synthesis. The product can be purified further by recrystallization from dichloromethane-hexane. Anal Calcd. for Ci0H2oN404SBrCo C, 27.85 H, 4.68 N, 12.99 Br, 18.53. Found C, 27.61 H, 4.59 N, 13.03 Br, 18.64. 

The steps involved in the synthesis of trimethylantimony dibromide are the same as those for the preparation of trimethylantimony dichloride up to the addition of the chlorine. Instead of a gas inlet tube, an addition funnel is mounted on the flask containing the ice-cold distillate of ethyl ether and trimethylstibine. A solution of 100 g. (0.627 mol) of bromine in 500 ml. of carbon tetrachloride is added dropwise while the reaction mixture is gently stirred. The addition is stopped when the slurry remains yellowish brown. The crude material is filtered with suction on a fritted Buchner funnel and washed several times with... 

Buchner RR, Hugh TE, Ember JA, Morgan EL (1995) Expression of functional receptors for human C5a anaphylatoxin (CD88) on the human hepatocellular carcinoma cell line HepG2. Stimulation of acute-phase protein-specific mRNA and protein synthesis by human C5a anaphylatoxin. J Immunol 155 308-315. 

The total synthesis of the diterpenoid tropone, harringtonolide was accomplished in the laboratory of L.N. Mander. The key step to form the seven-membered ring was the Buchner reaction of a complex polycyclic diazo ketone intermediate. Upon treatment with rhodium mandelate, an unstable adduct was formed and was immediately treated with DBU to afford the less labile cycloheptatriene. 

Buchner, E., Curtius, T. Synthesis of 3-keto esters from aldehydes and diazoacetic acid. Chem. Ber. 1885,18, 2371-2377. 

Anciaux, A. J., Demonceau, A., Hubert, A. J., Noels, A. F., Petiniot, N., Teyssie, P. Catalytic control of reactions of dipoles and carbenes an easy and efficient synthesis of cycioheptatrienes from aromatic compounds by an extension of Buchner s reaction. J. Chem. Soc.,... 

Duddeck, H., Ferguson, G., Kaitner, B., Kennedy, M., McKervey, M. A., Maguire, A. R. The intramolecular Buchner reaction of aryl diazoketones. Synthesis and x-ray crystai structures of some poiyfunctionai hydroazuiene iactones. J. Chem. Soc., Perkin Trans. 11990, 1055-1063. 

Ffau and Plattner employed a Buchner reaction for the synthesis of vetiva-zulene from the Indane derivative I. At the high temperature at which the condensation of I with ethyl dlazoacetute was carried out the adduct 11 was in part isomerized to III suponiilcation of the mixture completed the Isumoij/.iition, and dehydrogena-... 

Buchner, Eduard. (1860-1917). A German chemist who was awarded the Nobel Prize for chemistry in 1907. His works included the synthesis of diiodoacetamid through alcoholic fermentation... 

Preparation of acetaminophen (Tylenol) A multi-step synthesis. You ve just recrystallized 4-nitroaniline on the way to acetominophen, and washed and collected the product on your Buchner funnel. So you... 

The powdered sample was soaked in n-hexane for three days and the oil-hexane miscella was then filtered by suction through a Buchner funnel. Most of the -hexane in the mixture was removed using a rotary evaporator with the temperature of the bath set at 40 °C, and the resulting oil sample was left in a fume hood for 72 hours to allow the remaining solvent to evaporate. The oil was then treated with anhydrous Na2S04 to remove all moisture. The resulting dry oil was used for biodiesel synthesis by reaction of the oil with anhydrous methanol in presence of NaOH catalyst. 

Cl Sih, PR Ravikumar, FC Huang, C Buchner, H Whitelock Jr. Isolation and synthesis of pinoresinol diglucoside, a new antihypertensive principle of Tu-Chang (Eucommia uhnoides Oliver). JAm Chem Soc 98 5412-5413, 1976. 

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