Distillation, apparatus simple

Fig. 23(D) shows a simple distillation apparatus with an adaptor fitted to the lower end of the condenser. This apparatus can also be used for the recovery of solvents, or for the concentration of a solution with collection of the distilled solvent.

The solution is concentrated under reduced pressure. The remaining oil is distilled under reduced pressure using a simple distillation apparatus. After a small forerun, 27 g (0.179 mol, 26iS yield) (Note 5) of 1 is collected, as a light yellow oil, bp 90-94 C/O.05 mn (Note 6). Further purification is accomplished by a second distillation under reduced pressure, bp 90.2 C/0.05 mm (Notes 7 and 8). 

The submitters used a short path simple distillation apparatus bp aS-ST-C (0.2 mm). 

To the cooled reaction mixture, 200 ml. of water is added carefully with stirring. Potassium carbonate is added with continued stirring until the water layer is saturated the mixture is now transferred to a separatory funnel and extracted three times with 60-ml. portions of ether. The combined ether extracts are dried over solid sodium hydroxide and are then transferred to a simple distillation apparatus. Distillation is commenced with a steam bath as source of heat when most of the ether has been removed, the steam bath is replaced by a flame. Distillation is continued until most of the piperidine (b.p. 106°) has been removed. The cooled residue in the distillation flask is recrystallized from petroleum ether (boiling range 30-60°) with the use of charcoal. There is obtained 30.0 g. (71%) of N-/3-naphthyl-piperidine as tan crystals, m.p. 52-56°. An additional recrystallization from the same solvent gives crystals, m.p. 56-58°, with about 10% loss in weight (Note 6). 

A 1-1. steel bomb is charged with 200 g. (1.51 moles) of dicyclo-pentadiene (Note 1). The bomb is flushed with ethylene (Note 2) and then filled while shaking to an initial pressure of 800-900 p.s.i. at 25°. Shaking is continued as the bomb is slowly heated (Note 3) to 190-200° and maintained at this temperature for 7 hours (Note 4). At the end of this period, the reaction vessel is cooled and vented, and the crude product is transferred into a simple distillation apparatus (Note 5). A fraction boiling between 93° and 100° is collected, yield 162-202 g. (57-71%, based on dicyclopentadiene) (Note 6). The norbornylene may be redistilled with negligible losses to give a final product, b.p. 94-97°/740 mm., m.p. 44-44.5° (sealed capillary). 

A. AcetamidoaceUme. A mixture of 75.0 g. (l.O mole) of glycine (Note 1), 475 g. (485 ml., 6 moles) of pyridine (Note 1), and 1190 g. (1.1 1., 11.67 moles) of acetic anhydride (Notes 1 and 2) is heated under reflux with stirring for 6 hours (Note 3) in a 3-1., three-necked, round-bottomed flask. The reflux condenser is replaced by one set for downward distillation, and the excess pjnidine, acetic anhydride, and acetic acid are removed by distillation under reduced pressure. The residue is transferred to a simple distillation apparatus such as a Claisen flask and is distilled to give 80-90 g. (70-78%) of a pale yellow oil, b.p. 120-125° (1 mm.). This product is of satisfactory purity for use in step B. 

Figure 032. Simple distillation apparatus for the distillation of liquors, wines, or beers to yield 90%+ ethyl alcohol.

A simple distilling apparatus that can be nsed for this experiment is shown in Fig. 4. The mercury thermometer bulb (or any other thermometer sensor) should be about level with the side arm to the condenser so that the temperature of coexisting vapor and Uqnid is measured. Except when samples of distillate are being taken for analysis, an adeqnate receiving flask should be placed at the lower end of the condenser. 

A typical vacuum distillation apparatus is shown in Fig. 11.10. The chief difference from the simple distillation apparatus is in the design of the receiver adapter. This must allow several fractions to be collected without needing to break the vacuum. The simplest design is the pig type shown in... 

No matter what type of distillation you are attempting, it is essential that you assemble the apparatus correctly, since you are dealing with hot, often flammable, liquids and vapours. A typical simple distillation apparatus is shown in Fig. 15.1 and the method of assembly is described in Box 15.1. 

A simple distillation apparatus consisting of a 10-ml round-bottom microflask with a 4-cm neck fitted with a one-hole rubber stopper is fabricated. The latter supports a glass tube drawn out at one end to approximately 0.4 mm inside diameter on the receiver end. The tube is bent so that it will extend to the bottom of a 50-ml volumetric flask. Absorption measurements are made with matched l-cm Corex cells, or equivalent, using a prism spectrophotometer. Any final pH adjustments on the test solution are made with a pH meter. 

A t3rpical vacuum distillation apparatus is given in Fig. 3.15. The prominent and major difference in comparison to a simple distillation apparatus is in the design of the receiver adapter. The skilful design of the receiving adapter permits the collection of several fractions successively without breaking the initially attained vacuum in the distillation assembly. 

Rgure 3.7. Simple distillation apparatus. (Figure modified from Chemweb 2005.)... 

Figure 1 Simple distillation apparatus comprising distillation flask (DF), distillation head (DFI), thermometer (T), condenser (C), and receiver (or collection) flask (RF). (Reproduced from Furniss BS, Flannaford AJ, Smith PWG, and Tatchell AR (1989) Vogel s Textbook of Practical Organic Chemistry, 5th edn., pp. 168-197. Flarlow Longman Scientific and Technical.)...

The reflux ratio, that is, the ratio of material returning via reflux to the distillation column or the distillation flask compared to the amount presented to the condenser in unit time must be carefully controlled. The higher the reflux ratio, the purer the material collected from the distillation. Reflux ratios are controlled in simple distillation apparatus by adjustment of the heating rate and by maintaining stable thermal conditions throughout the apparatus. 

Setting Up Place 10 mL of cyclohexane containing a nonvolatile dye in the round-bottom flask. Add a stirbar to the flask to ensure smooth boiling, and assemble the simple distillation apparatus shown in Figure 2.37a. Be sure to position the thermometer in the stillhead so the top of the mercury thermometer bulb is level with the bottom of the sidearm of the distillation head. Flave your instructor check your apparatus before you start heating the stillpot. 

Compare the results of a fractional distillation using a packed column, as described in the above experimental procedure, with those obtained using a simple distillation apparatus, an unpacked column, and one packed with a material different from that used originally. 

FIGURE 7.20 Apparatus for simple distillation. Compare these with Figure 7.9. (a) Normal-scale simple distillation apparatus, (b) Microscale simple distillation apparatus. 

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