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.

    459/490 (page 437)
    soln. with dil. hydrochloric acid. Recryst. hot water. Yield 00% . Note m.-pt. Compare with phenol tests. Oxidation of Naphthalene to Phthalic Acid.—(See chap, lii.) CHAPTER LXI Anthraquinone.—8 grams anthracene in 10 c.c. glacial acid; 12 grams chromium trioxide in 18 c.c. acid gradually added. Sublime. Note colour , and m.-pt. Conversion of Anthraquinone into Benzoic J^eid.—Fuse 3 grams in iron spoon at 200° with 3 grams caustic soda and 1 c.c. water. Dissolve melt in water and ppt. benzoic acid with dil. hydrochloric acid. Collect, wash, dry, and sublime ; identify by m.-pt. and tests. [Sodium Anthraquinone-Sulphonate.—4 grams anthraquinone, 10 c.c, fuming sulphuric acid; heat until nearly all dissolved. Dilute, filter, neutra- lise hot with sodium carbonate ; sodium salt cryst. on cooling.] [Alizarin.—2 grams sulphonate, 7 grams caustic soda, ] gram potassium chlorate, 10 c.c. water. Heat in sealed tube (one-third full) for day and night at 165-175°. Extract alizarin with boiling water and ppt. dye with dilute- acid. Wash, dry, and sublime. Note m.-pt., colour, solubility in caustio alkalies, and pptn. from these solns. by metallic salts. Note colours of- lakes.j CHAPTER LXII Azoxybenzene.—4 grams sodium, 20 c.c. dry alcohol; 5 c.c. nitrobenzene. Note m.-pt. Yield 50% . Distil some with fine iron filings and compare azobenzene with that prepared by following method. Azobenzene.—Boil 10 grams caustic soda, 50 c.c. nieth. spirit until nearly dissolved (reflux appts.); then add at ordinary temp. 10 c.c. nitrobenzene. After 2 hours add 6 grams zinc dust and boil for 3 hours. Dist. off alcohol, extract residue with hot water, wash with dil. hydrochloric acid to remove zinc cpds. Finally wash with water an d extract with boiling alcohol. Yield 70% . Purify, and note m.-pt. and red. vapour. Amido-Azobenzene.—5 grams aniline hydrochloride, dissolved in 20 c.c. aniline at 35°; add 2'5 grams sodium nitrite in minimum qty. water (3 or 4 c.c.). Keep at 35-40° for 1§ hours. Next day stir in 14 c.c. cone, hydrochloric acid; strain and press ; dissolve liquid in excess of dilute acid, filtev; add excess of caustic soda ; collect and crystallise residue. [Triamido-Azobenzene.—A few drops of a dilute soln. of metaphenylene- diamine salt to soln. contg. trace of nitrite. Can be used for the colorimetric1 estimation of nitrites in water.] [.Methyl Orange.—Make sulphanilic acid : 10 c.c. aniline heated for 5 hours at 20° with 20 c.c. cone, sulphuric acid. Crystallise repeatedly from hot water. Use 12 grams acid in 200 c.c. water; neutralise with washing soda. Calculated qties. for diazo, etc. Note red with acids, colourless with alkalies.] CHAPTER LXIII Quinoline.—10 c.c. nitrobenzene, 20 c.c. aniline, 50 c.c. glycerol; mix and cautiously stir in 30 c.c. cone, sulphuric acid. Yield 40%. Note b.-pt., odour. Make hydrochloride and crystallise. Quinolinic Acid.—5 c.c. quinoline in good sized flask (reflux) with 5 grams permanganate in 100 c.c. water. Boil until pimple colour (of clear liquid) disappears. Then add gradually through condenser, still boiling, 5 grams permanganate in 100 c.c. water, until purple colour permanent. Filter off manganese dioxide, slightly acidify with dil. sulphuric acid, decolourise excess of permanganate with drop of sulphite solution, and shake out with ether. Note m.-pt.