File:Image from page 335 of "Practical methods of organic chemistry" (1901) (14585181107).jpg

Identifier: practicalmethods00gatt Title: Practical methods of organic chemistry Year: 1901 (1900s) Authors: Gattemann, Ludwig. [from old catalog] Subjects: Publisher: [n.p.] Contributing Library: The Library of Congress Digitizing Sponsor: The Library of Congress

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Text Appearing Before Image: th these substances the other reaction is useless. (See B. 19, 1765 ;32, 278, etc.) 39. REACTION: KOLBES SYNTHESIS OF OXYACIDS Example : Salicylic Acid from Sodium Phenolate andCarbon Dioxide1 Dissolve 12J grammes of chemically pure sodium hydroxide in20 c.c. of water in a porcelain dish, or better a nickel dish, andwith stirring, treat gradually with 30 grammes of crystallised phe-nol. The greatest portion of the water is then evaporated by heating over a free flame,the mass being continuallystirred. As soon as a crys-talline film forms on thesurface of the liquid, theheating is continued witha luminous flame, which isnot placed directly underthe dish, but is kept in con-stant motion. In order tofasten the dish, a pair ofcrucible tongs is clampedin a vertical position, andthe dish supported betweenits jaws. There is first ob-tained a caked, bright-coloured mass, which is crushed from timeto time with a mortar-pestle. As soon as the particles no longer 1 J.pr. [2] 10,89; 27,39; 3L397-

Text Appearing After Image: Fig. 77. AROMATIC SERIES 317 bake together, the mass is pulverised quickly in a dry mortar, thedry mass is then heated with thorough stirring in a nickel dish todusty dryness. It is then placed in a tubulated retort of 200 c.c.capacity. The retort is then immersed as far as possible in an oil-bath (Fig. 77). This is heated to no°, and at this temperaturea current of dry carbon dioxide is passed over the sodium pheno-late (the end of the delivery tube is 1 cm. above the upper surfaceof the sodium phenolate) ; this is passed into the retort for anhour. The temperature is then gradually raised (200 per hour)during the course of four hours, while a not too rapid current ispassed in, to 1900. The mixture is finally heated 1-2 hours at2000. During the operation the mass is stirred several times witha glass rod. After cooling, the phenol in the neck of the retort ismelted by the application of a flame to the outside, the dusty, finepowder is poured into a large beaker, the retort is washed

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