Condensate connections

Y-Phenylbutyric acid. Prepare amalgamated zinc from 120 g. of zinc wool contained in a 1-litre rovmd-bottomed flask (Section 111,50, IS), decant the liquid as completely as possible, and add in the following order 75 ml. of water, 180 ml. of concentrated hydrochloric acid, 100 ml. of pure toluene (1) and 50 g. of p benzoylpropionic acid. Fit the flask with a reflux condenser connected to a gas absorption device (Fig. II, 8, l,c), and boil the reaction mixture vigorously for 30 hours add three or four 50 ml. portions of concentrated hydrochloric acid at approximately six hour intervals during the refluxing period in order to maintain the concentration of the acid. Allow to cool to room temperature and separate the two layers. Dilute the aqueous portion with about 200 ml. of water and extract with three 75 ml. portions of ether. Combine the toluene layer with the ether extracts, wash with water, and dry over anhydrous magnesium or calcium sulphate. Remove the solvents by distillation under diminished pressure on a water bath (compare Fig. II, 37, 1), transfer the residue to a Claisen flask, and distil imder reduced pressure (Fig. II, 19, 1). Collect the y-phenylbutyric acid at 178-181°/19 mm. this solidifies on coohng to a colourless sohd (40 g.) and melts at 47-48°. 

The apparatus consists of a l-l. three-necked flask fitted with a gas inlet tube extending about 3 cm. into the flask and connected to the flask through a bubbler, a thermometer extending to the bottom, a mechanical stirrer, and a reflux condenser connected at the upper end with an exit tube leading to the hood. The reaction is carried out in an atmosphere of illuminating gas (Note 1). 

In a 5-I. round-bottomed flask, equipped with a reflux condenser connected to a gas trap (Note 1), are placed 2 1. (12.r moles) of 20 per cent hydrochloric acid and 500 g. (5.05 moles) of allyl isothiocyanate (Note 2). The mixture is refluxed over a free flame until the upper layer of allyl isothiocyanate has completely disappeared, about fifteen hours being required for the hydrolysis. When the reaction is complete, the solution is -poured into a 3-I. beaker and concentrated on the steam bath until crystals begin to form in the hot solution. This occurs when the volume is approximately 400 cc. (Note 3). 

The apparatus should be set up under a hood, or the top of the condenser connected to a gas absorption trap for the removal of bromine vapor, a small amount of which escapes continually under the conditions of the experiment. 

A 300-mL three-necked flask is equipped with a mechanical stirrer and a reflux condenser connected to a vacuum system through a cold trap. 

B. Benzobarrelene. A dry 1-1., three-necked, round-bottomed flask is equipped with a magnetic stirring bar, a combined gas-inlet tube and rubber septum, a 500-ml. pressure-equalizing dropping funnel, and a reflux condenser connected to a Nujol bubbler. The flask is charged with 500 ml. of dry tetrahydrofuran (Note 14) and 17 g. (0.74 mole) of sodium wire with a diameter of ca. 0.5 mm. The mixture is stirred and heated at reflux under an atmosphere of argon or nitrogen, and 50 ml. of freshly distilled tert-butyl alcohol is added. Immediately afterward a solution of 15 g. (0.051 mole) of... 

C. Active magnesium. A 200-ml., three-necked, round-bottomed flask is equipped with a Teflon-coated magnetic stirring bar, stopper, rubber septum, and condenser connected to an argon inlet (Note 6). The flask is charged with 1.5 g. (0.038 mole) of freshly cut potassium (Notes 7 and 8), 2.01 g. (0.0211 mole) of anhydrous magnesium chloride (Note 9), 3.55 g. (0.0214 mole) of anhydrous potassium iodide (Note 10), and 50 ml. of tetrahydrofu-ran (Note 11). The mixture is stirred vigorously (Note 12) and... 

A 500-ml. three-necked round-bottomed flask is provided with a small dropping funnel, a sealed mechanical stirrer, a reflux condenser connected to a gas-absorption trap, and a hydrogen chloride delivery tube which extends, to the bottom of the flask. 

A 1-1. three-necked round-bottomed flask is mounted on a steam cone and is fitted with a 250-cc. separatory funnel and a reflux condenser connected to a trap (Note 1) for absorbing gases. In the flask is placed 325 g. (198 cc., 2.73 moles) of thionyl chloride (Note 2), and to it is added, during the course of one hour, 125 g. (0.58 moles) of /-menthoxyacetic acid (p. 52). The flask is shaken frequently during the addition of the acid and, if necessary, is warmed to start the reaction. When all the acid has been added... 

A 50-ml., round-bottomed flask equipped with a magnetic stirring bar and a 20-ml. calibration mark (Note 1) is charged with 970 mg. (2.5 mmoles) of 4-cholesten-3/9-ol (Note 2). Ethyl vinyl ether is distilled into the flask to the 20-ml. mark (Note 3). The mixture is stirred to effect solution then 820 mg. (2.55 mmoles) of mercuric acetate (Note 4) is added to the reaction mixture. The flask is fitted with a reflux condenser connected to a gas inlet tube and flushed with argon. The reaction mixture is then stirred and heated (Note 5) at reflux under a positive argon pressure for 17 hours. After the solution has cooled to room temperature, 0.062 ml. (1.09 mmoles) of glacial acetic acid (Note... 

Dichlorophenoxyacetyl chloride i4)was prepared by addition of 110.0 g (0.498 moles) of 2,4-dichlorophenoxyacetic acid in 250 ml of benzene and 7 ml of N,N-dimethylformamide (DMF) into a one liter, 3-necked roundbottomed flask equipped with mechanical stirrer, addition funnel, thermometer and condenser connected to a caustic scrubber. After heating to reflux, a solution of... 

Dichloropropionyl chloridefiS was prepared by charging a two liter, 3-necked, roundbottom flask equipped with mechanical stirrer,thermometer, addition funnel, and condenser connected to a caustic scrubber with 250 g of 2,2-dichlorophenoxyacetic acid in 500 ml of chloroform and 10 ml of DMF. The mixture was refluxed for one hour, followed by the addition of 328 g of thionyl chloride over a period of one hour. The mixture was refluxed for two additional hours. After removal of excess thionyl chloride and solvent, the crude product was vacuum distilled yielding 210 g of the acid chloride (b.p. 75°C 20 mm). 

A 500 ml resin kettle was fitted with a stirrer, dropping funnel, and a condenser connected with a drying tube. 

An oven-dried 100 ml flask with a side arm dosed with a septum is fitted with a magnetic stirring bar and a reflux condenser connected to a mercury bubbler. The flask is cooled to room temperature under nitrogen, charged with 4.36 g (0.025 mol) of adipic acid monoethyl ester followed by 12.5 ml of anhydrous tetrahydrofuran, and cooled to —18° by immersion in an ice-salt bath. Then 10.5 ml of 2.39 m (or 25 ml of 1 m) solution of borane in tetrahydrofuran (0.025 mol) is slowly added dropwise over a period of 19 minutes. The resulting clear reaction mixture is stirred well and the ice-salt bath is allowed to warm slowly to room temperature over a 16-hour period. The mixture is hydrolyzed with 15 ml of water at 0°. The aqueous phase is treated with 6 g of potassium carbonate (to decrease the solubility of the alcohol-ester in water), the tetrahydrofuran layer is separated and the aqueous layer is extracted three times with a total of 150 ml of ether. The combined ether extracts are washed with 30 ml of a saturated solution of sodium chloride, dried over anhydrous magnesium sulfate, and evaporated in vacuo to give 3.5 g (88%) of a colorless liquid which on distillation yields 2.98 g (75%) of ethyl 6-hydroxyhexanoate, b.p. 79°/0.7 mm. 

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