Introduction to the study of organic chemistry : a text-book for students in the universitites and technical schools / by John Wade.

  • Wade, John.
Date:
1898
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Licence: Public Domain Mark

Credit: Introduction to the study of organic chemistry : a text-book for students in the universitites and technical schools / by John Wade. Source: Wellcome Collection.

    456/490 (page 434)
    Cool and stir ; sulphanilic acid separates ; nearly neutralise silver with wash- ing soda, add excess caustic soda and extract with ether.] CHAPTER XLIX [Resorcinol.—Heat 10 grams sodium benzene sulphonate with 20 c.c. fuming sulphuric acid in reflux apparatus on sand-bath for 2 hours. Isolate sodium disulphonate (+ unchanged monosulpbonate) by calcium carbonate method. Fuse the mixed mono- and di-sulphonate with potash as in phenol prepn., and sept, phenol and resorcinol by fract. distn. Note m.-pt. and colour with ferric chloride.] [Quinol.—Use crude black quinone product as before ether extraction. Yield 25% .] Quinone.—10 c.c. aniline, 50 c.c. cone, sulphuric acid, 250 c.c. water, ice- cooled ; add 12 grams powdered bichromate in minimum qty. of water. Keep overnight at ordinary temp. Next day cool again, and add 24 grams bichromate in min. qty. water. After 3 hours, extract ; 3 extractions. Distil off ether on w.-b.; residue with steam. Yield 30%. Note m.-pt., colour, volatility, odour. [Phloroglucinol.—h grams resorcinol, 25 grams caustic soda, 3 c.c. water. Yield 60% . Note m.-pt. and ferric chloride colour.] Pyrogallol.—Heat gallic acid to its m.-pt. in test tube. Note carbon dioxide and sublimed pyrogallol. M.-pt. of latter, and colour with iron salts. Absorption of oxygen from air by its solu. in caustic alkali. CHAPTER L Salicylic Acid.—Dissolve 5 grams caustic soda in 7 c.c. w ater in iron dish ; add 10 grams phenol; heat gently and stir vigorously until powder obtained —not cake. Place in dist. flask, and pass washed and dried carbon dioxide raising temperature gradually from 100s to 200°—4 hours. Yield 50% . Note m.-pt. and tests. Qualitative Tests for Salicylic Acid (p. 303).-—Violet with ferric chloride) in neutral soln. not changed by acetic acid. Flocculent tribromo-epd. In- timate mixture with lime gives phenol (odour: picric acid). Qualitative Tests for Gallic Acid (p. 306).—Blue-black withferiic or ferro- so-ferric salts. No ppt. with gelatine. Rufigallic acid—moisten solid with cone, sulphuric acid on watch-glass, warm till red, turn into cold water. Qualitative Tests for Tannin (p. 306).—Blue-black with iron salts. Ppt. with cold, fresh gelatine solution. (Soak fragment of gelatine in cold water until it swells, then warm with a little water.) Rufigallic acid, as with gallic acid. CHAPTER LI Toluene-sulphonic Acid.—Mixed o- and ^-compounds in same way as with benzene, but more easily. Cresols.—Mixed o- and p-epds. as with phenol. Note colours and b.-pts. Nitrotoluenes and Toluidines. —Mixed o- and p-epds. iu same way as nitrobenzene and aniline. Note b.-pts. Separate bases with sulphuric acid. CHAPTER LII Paratoluic Acid from Paratoluidine.—Precisely as with benzoic acid from aniline. Note m.-pt. and reactions (same as benzoic acid), [Paraxylene.—Distil 10 grams camphor with 10 grams zinc chloride. Warm product with cone, hydrochloric acid; wash with alkali and water; dry and fractionate.] Plithalic Acid and Anhydride.—6 grams naphthalene and 11 grams potassium chlorate (separately powdered), mixed and added slowly (draught cupboard) to 40 c.c. cone, hydrochloric acid. Washed chloride placed in re-