Apparatus for distillation and refluxing

Apparatus for distillation and refluxing (typical assemblies), 88-89, 226f-228t... 

Fit up the apparatus shown in Fig. Ill, 31, 1 the capacity of the Claisen flask should be 100 ml. Place 40 g. (24-6 ml.) of redistilled thionyl chloride in the flask and 60 g. (62 ml.) of dry n-butyl alcohol (b.p. 116-117°) in the dropping funnel. Cool the flask in ice and add the n-butyl alcohol, with frequent shaking, over 1 hour (1). Reflux the mixture gently for 1 hour to complete the reaction and to remove the residual hydrogen chloride. Arrange the apparatus for distillation, and distil under normal pressure until the temperature rises to 120° then distil under diminished pressure (Fig. 11, 20, 1) and collect the di-n-butyl sulphite at 116-118°/20 mm. The yield is 66 g. 

Place 36 -0 g. of redistilled acetophenone, b.p. 201° (Section IV,136), 300 ml. of diethylene glycol, 30 ml. of 90 per cent, hydrazine hydrate and 40 g. of potassium hydroxide pellets in a 500 ml. Claisen flask provided with a reflux condenser and a thermometer dipping into the liquid (compare Fig. Ill, 31, 1). Warm the mixture on a boiling water bath until most of the potassium hydroxide has dissolved and then reflux (free flame) for one hour. Arrange the apparatus for distillation and distil until the temperature in the liquid rises to 175° (1) keep the distillate (ca. 50 ml.). Replace the reflux condenser in the flask and continue the refluxing for 3 hours. 

Reaction in the absence of catalyst. Assemble in a fume cupboard a 500-ml three-necked flask equipped with a sealed stirrer unit, a double surface reflux condenser and a separatory funnel fit the condenser and the funnel with calcium chloride guard-tubes. Place 179 g (109.5 ml, 1.5 mol) of redistilled thionyl chloride in the flask and 51 g (62.5 ml, 0.5 mol) of hexan-l-ol, b.p. 156-158 °C, in the separatory funnel. Add the alcohol with stirring during 2 hours there is a slight evolution of heat, sulphur dioxide is evolved and the liquid darkens considerably. When all the alcohol has been added, reflux the mixture for 2 hours. Rearrange the apparatus for distillation, and distil slowly the excess of thionyl chloride passes over below 80 °C, followed by a small fraction up to 120 °C and finally the crude 1-chlorohexane at 132— 134 °C. Wash the last-named successively with water, 10 per cent sodium carbonate solution, and twice with water. Dry with anhydrous calcium chloride and distil through a short fractionating column. Pure 1-chlorohexane passes over at 133-134 °C. The yield is 36 g (60%). 

Fit a reflux condenser into the short neck of a 125 ml. Claisen flask, a separatory funnel into the long neck, and plug the side arm with a small cork (compare Fig. Ill, 31, 1). Place 58 g. (62 ml.) of commercial n-caproic acid (1) in the flask and heat on a water hath. Add 75 g. (46 ml.) of redistilled thionyl chloride through the separatory funnel during 45 minutes shake the flask from time to time to ensure thorough mixing. Reflux the mixture for 30 minutes. Arrange the apparatus for distillation from an air bath (Fig. II, 5, 3) the excess of thionyl chloride passes over flrst, followed by n-caproyl chloride at 145-155° (mainly at 150-155°). The yield of acid chloride is 56 g. 

In a 500 ml. three-necked flask, equipped with a thermometer, mechanical stirrer and efficient reflux condenser, dissolve 16 g. of sodium hydroxide pellets in 95 ml. of hot methyl alcohol. Add 49 g. of guanidine nitrate, stir the mixture at 50-65° for 15 minutes, and then cool to about 20°. Filter oflF the separated sodium nitrate and wash with two 12 ml. portions of methyl alcohol. Return the combined filtrates to the clean reaction flask, add 69 g. of sulphanilamide (Section IX,9) and stir at 50-55° for 15 minutes. Detach the reflux condenser and, with the aid of a still-head ( knee-tube ), arrange the apparatus for distillation from an oil bath with stirring about 100 ml. of methyl alcohol are recovered. Add 12 g. of pure cycZohexanol. Raise the temperature of the oil bath to 180-190° and continue the distillation. Reaction commences with the evolution of ammonia when the uiternal temperature reaches 145°. Maintain the... 

Allyl cyanide. Into a 2-litre three-necked flask, provided with a sealed stirrer and two long double surface condensers, place 293 g (210 ml, 2.42 mol) of freshly distilled allyl bromide, b.p. 70-71 °C (Expt 5.54) and 226 g (2.52 mol) of dry copper(i) cyanide (Section 4.2.23, p. 429). Warm the flask on a water bath so that the allyl bromide refluxes but do not stir at this stage. Immediately the vigorous reaction commences (after 15-30 minutes), remove the water bath and cool the flask in a bath of ice and water the two double surface condensers will prevent any loss of product. When the reaction subsides, start the stirrer and heat the mixture on the water bath for 1 hour. Remove the condensers and arrange the apparatus for distillation close one neck with a stopper. Heat the flask in an oil bath, and distil the allyl cyanide with stirring it is advisable to reduce the pressure (water pump) towards the end of the distillation to assist the removal of the final portion of the allyl cyanide from the solid residue. Redistil and collect the pure allyl cyanide at 116-121 °C. The yield is 140 g (86%). 

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