Thermometer spirit

Gently warm a mixture of 32 g. (32 ml.) of ethyl acetoacetate and 10 g. of aldehyde-ammonia in a 400 ml. beaker by direct heating on a gauze, stirring the mixture carefully with a thermometer. As soon as the reaction starts, remove the heating, and replace it when the reaction slackens, but do not allow the temperature of the mixture to exceed 100-no the reaction is rapidly completed. Add to the mixture about twice its volume of 2A -hydrochloric acid, and stir the mass until the deposit either becomes solid or forms a thick paste, according to the quality of the aldehyde-ammonia employed. Decant the aqueous acid layer, repeat the extraction of the deposit with more acid, and again decant the acid, or filter off the deposit if it is solid. Transfer the deposit to a conical flask and recrystallise it twice from ethanol (or methylated spirit) diluted with an equal volume of water. The i,4-dihydro-collidine-3,5-dicarboxylic diethyl ester (I) is obtained as colourless crystals, m.p. 130-131°. Yield 12 5 g,... 

Hydrolysis of benzyl cyanide to phenylacetamide. In a 1500 ml. three-necked flask, provided with a thermometer, reflux condenser and efficient mechanical stirrer, place 100 g. (98 ml.) of benzyl]cyanide and 400 ml. of concentrated hydrochloric acid. Immerse the flask in a water bath at 40°. and stir the mixture vigorously the benzyl cyanide passes into solution within 20-40 minutes and the temperature of the reaction mixture rises to about 50°, Continue the stirring for an additional 20-30 minutes after the mixture is homogeneous. Replace the warm water in the bath by tap water at 15°, replace the thermometer by a dropping funnel charged with 400 ml. of cold distilled water, and add the latter with stirring crystals commence to separate after about 50-75 ml. have been introduced. When all the water has been run in, cool the mixture externally with ice water for 30 minutes (1), and collect the crude phenylacetamide by filtration at the pump. Remove traces of phenylacetic acid by stirring the wet sohd for about 30 minutes with two 50 ml. portions of cold water dry the crystals at 50-80°. The yield of phenylacetamide, m.p. 154-155°, is 95 g. RecrystaUisation from benzene or rectified spirit raises the m.p. to 156°. 

Cloud point. Measures the solubility/compatibility of a resin with solvents. The value reported is the temperature at which a specific mixture of a resin and a solvent or solvents blend gives a cloudy appearance, having been cooled from a temperature at which the mixture was clear. Commonly, a test tube of a given diameter is used and the temperature is noted when the lower end of the thermometer, placed at the bottom of the tube, disappears. Resins with cloud points below 0°C are commonly regarded as soluble and cloud points greater than 10°C indicate poor solubility/compatibility. White spirit with various aromatic contents is a widely used solvent in the determination of cloud point, but other solvents or solvents mixtures are also used. 

Methylated spirit contains, in addition to ethyl and methyl alcohols, water, fusel-oil, acetaldehyde, and acetone. It may be freed from aldehyde by boiling with a—3 per cent, solid caustic potash on the water-bath with an upright condenser for one hour, or if larger quantities are employed, a tin bottle is preferable, which is heated directly over a small flame (see Fig. 38). It is then distilled with the apparatus shown in Fig. 39. The bottle is here surmounted with a T-piece holding a thermometer. The distillation is stopped when most of the spirit has distilled and the thermometer indicates 80°. A further purification may be effected by adding a little powdered permanganate of potash and by a second distillation, but this is rarely necessary. The same method of purification may be applied to over-proof spirit, which will henceforth be called spirit as distinguished from the purified product or absolute alcohol. 

Spiramycin complex, 15 290, 29 It, 300 Spirit soluble azo dyes, 9 421 Spirit thermometers, 24 464... 

To prepare absolute alcohol, 100 gms. of freshly burnt quicklime in the form of small lumps are placed in a 500-c.c. distilling flask, and 300 gms. of rectified spirits added. After 8 hours the alcohol is distilled off on a water bath until a thermometer in the neck of the flask indicates 80°. The alcohol so obtained still contains about 3% of water. 

Place a mixture of 114 g (140 ml, 1.0 mol) of heptan-2-one (1), 300 ml of rectified spirit (95% ethanol) and 100 ml of water in a 1.5-litre three-necked flask fitted with an efficient double surface condenser and a thermometer dipping into the reaction mixture. Through the third neck add 65 g (2.8 mol) of clean sodium, preferably in the form of wire (Section 4.2.65, p. 462) although small pieces may be used with somewhat inferior results, gradually and at such a... 

In a 1-litre three-necked flask, equipped with a reflux condenser, a mechanical stirrer and a thermometer dipping into the reaction mixture, place 50 g (0.275mol) of benzophenone (Expt 6.121), 500ml of rectified spirit, 50g of sodium hydroxide and 50 g (0.76 mol) of zinc powder. Stir the mixture the temperature slowly rises to about 70 °C. After 3 hours, when the temperature has commenced to fall, filter the reaction mixture with suction and wash the residue twice with 25 ml portions of hot rectified spirit. Do not allow the residual zinc powder to become dry as it is flammable. Pour the filtrate into 2 litres of ice water acidified with 100 ml of concentrated hydrochloric acid. The benzhydrol separates as a white crystalline mass. Filter at the pump and dry in the air. The yield of crude benzhydrol, m.p. 65 °C, is 49 g. Recrystallise from 50 ml of hot ethanol and cool in a freezing mixture of ice and salt. Collect the colourless crystals and dry in the air 36 g of pure benzhydrol, m.p. 68 °C, are obtained. Dilute the mother-liquor with water to precipitate the residual benzhydrol, and recrystallise this from a small quantity of hot alcohol. 

Cognate preparations. Cyclohexane-1,2-dione. Equip a 1-litre, three-necked flask with a reflux condenser, thermometer and dropping funnel. Place 250 g (2.55 mol) of pure cyclohexanone in the flask, heat to 70-80 °C and add a solution of 280 g (2.52 mol) of pure selenium dioxide in 1500 ml of rectified spirit from the dropping funnel over a period of 2 hours, maintaining the temperature at 70-80 °C. Reflux the reaction mixture for a further 2 hours. Distil off as much of the alcohol as possible and decant the liquid residue from the elemental selenium. Wash the latter several times with ether, and combine the... 

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