Funnel , addition Buchner, recrystallization

In a 5-I. flask, equipped with a mechanical stirrer, a reflux condenser and a separatory funnel, is placed 3 kg. of 75 per cent sulfuric acid (sp. gr. 1.67). The solution is heated to about 150°, the stirrer is started and r kg. (8.55 moles) of o-tolunitrile (Org. Syn. 4, 69) is added during the course of two hours. The temperature is maintained at 150-160° and the mixture is stirred for two hours after the addition of the nitrile is complete. The temperature is then raised to 190° and stirring is continued for another hour. Usually some crystalline material appears in the condenser at this stage. The reaction mixture is cooled, poured into ice water and filtered. The crude material is dissolved in an excess of 10 per cent sodium hydroxide solution (Note 1), filtered hot and the filtrate acidified with dilute sulfuric acid. The product is collected on a Buchner funnel, dried and recrystallized from about 3 1. of benzene (Note 2). The yield is 930-1030 g. (80-89 cent °f the theoretical amount) of a product which melts at 102-103° (Note 3). 

TsCl was obtained from Aldrich Chemical Company, Inc. and purified by recrystallization according to the following procedure. p-Toluenesulfonyl chloride (85 g) is dissolved in 150 mL of hot CHC13 and 200 ml. of petroleum ether (room temperature) is added in one portion to the clear, colorless solution. The resulting cloudy solution is clarified by addition of ca. 5 g of charcoal, stirred for 1 min, and filtered on a Buchner funnel. The filtrate is concentrated to ca. l/5th of its original volume by rotary evaporation, and the solid which appears is collected by filtration and dried under reduced pressure (25° C, 0.03 mm) to afford 68 g of TsCl as bright white crystals. 

Distillation of the alcoholic filtrate (Caution Note 5) under reduced pressure and in an atmosphere of nitrogen permits the isolation of an additional 8-10 g. of 3,4-dinitro-3-hexene. The blue oil boiling below 75°/20 mm. is discarded. To the undistilled residue is added 25 ml. of 95% ethanol, the resulting solution is cooled in an ice-salt bath, and the crystals are collected on a cold Buchner funnel and washed with 5 ml. of ice-cold alcohol. The combined crops of crystals are recrystallized from 80 ml. of 95% ethanol. The pure 3,4-dinitro-3-hexene separates as light-yellow needles, m.p. 31-32°, weight 50-55 g. (29-32%) (Note 6). 

Addition of HC1 to the benzoic acid extract will produce huge amounts of white crystals. Get out the Buchner funnel and have a field day Collect all you want. But they won t be in the best of shape. Recrystallize them. ("Note This compound is insoluble in the aqueous recovery solution.)... 

The isomerized rosin, 245 g. (0.72 mole) (Note 1), is placed in a 1-1. Erlenmeyer flask and dissolved in 375 ml. of acetone by heating the mixture on a steam bath. To this solution, at incipient boiling, is added slowly and with vigorous agitation (Note 5) 127 g. (0.81 mole) of diamylamine 2 (Note 6). Upon cooling to room temperature, crystals appear in the form of rosettes. The mass is agitated, cooled well in an ice bath, and filtered by suction. The crystalline salt is washed on a Buchner funnel with 150 ml. of acetone and dried in a vacuum oven at 50° for 1 hour. The optical rotation of this material is [< ]d —18° (Note 4). The solid is recrystallized four times from acetone. Each time a sufficient quantity (20 ml. per g.) of acetone is used to obtain complete solution, and the solvent is evaporated until incipient precipitation of the salt occurs. The yield of product is 118 g. [ ]d —60° (Note 4). An additional 29 g. of product, having the same rotation, can be recovered from filtrates of the previous crystallizations. 

In a 2-1. round-bottom flask, equipped with a stirrer, are placed 231 g. (0.5 mole) of the addition compound of /3-naphthalene diazonium chloride and mercuric chloride (p. 55), 700 cc. of acetone (b.p. 55-57°) and 189 g. (3 moles) of copper powder (Note 1). The mixture is quickly cooled to 20° and stirred for one hour. The mixture is treated with 700 cc, of concentrated aqueous ammonia solution (sp. gr. 0.9), mixed well, and allowed to stand overnight. The supernatant liquid is decanted the solid is collected on a Buchner funnel and washed successively with 25-cc. portions of water, acetone, and ether. After airdrying, the crude material is recrystallized from xylene, using decolorizing carbon. The crystals thus obtained are slightly yellow (Note 2) and melt at 241.5-243.50. The yield is 51-55 g. (45-48 per cent of the theoretical amount based on the addition compound used). 

A solution of 100 g. (1.06 moles) of phenol in 11. of methanol is allowed to drop at a rate of 110 ml. per hour (Note 1) over an activated alumina catalyst (Note 2) heated to 530° (Note 3). The exit from the hot tube is attached to a receiver arranged to lead by-product gases to an efficient hood (Note 4). After addition of the methanol solution is finished, the pale yellow product is transferred to a Buchner funnel and washed with methanol. The yield of crude product melting at 135-145° is 112-115 g. (65-67%). Recrystallization from ethanol (50 g. in 650 ml.) gives 85% recovery or from benzene (50 g. in 130 ml.) gives 60% recovery of colorless hexamethylbenzene, m.p. 165-166°. 

The preparation of trimethylantimony diiodide is identical to that of trimethylantimony dichloride up to the point of the addition of 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. For a reaction carried out on the basis of 0.25 mol of anhydrous antimony(III) chloride, a solution of 63,5 g. (0.25 mol) of iodine in 400 ml. of ethyl ether is prepared. This solution is added dropwise to the cold distillate. Stirring is maintained and the addition is continued until the color of iodine persists. The precipitate of trimethylantimony diiodide is filtered off on a fritted Buchner fuimel and washed with ethyl ether. The jdeld of the crude product is 47.7 to 65.3 g. (45.0 to 61.8% of theoretical based upon antimony (III) chloride). The diiodide may be recrystallized from ethanol. Anal. Calcd. for (CH3) 3Sbl2 Sb, 28.95 C, 8.55 H, 2.16. Found Sb, 29.31 C, 8.16 H, 2.25. The checkers report that the foregoing syntheses are also satisfactory using one-half the amounts prescribed. 

Recrystallized preparations of acrylamide are available commercially or may be prepared as follows. Dissolve acrylamide (70 g) in 1 liter chloroform at 50°C. Filter the solution hot and cool it to —20°C to bring about crystallization. Collect the crystalline acrylamide in a chilled Buchner funnel, wash with chilled (—20°C) chloroform and/or heptane, and dry. Additional discussion of the purification of reagents used for electrophoresis may be found elsewhere (35,36). 

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