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.

    454/490 (page 432)
    filings from test tube, heating from front backwards. Identify benzene by nitration. Yield 50% . Benzonitrile from Aniline.—Diazotise 10 c.c. aniline as in elimination of amido-group, and pour slowly, with vigorous shaking, down condenser of reflux appts. containing cuprous soln. at ordinary temp. Cuprous soln. made by adding (in good draught—poisonous cyanogen evolved in large qties.) hot soln. of copper sulphate soln. (26 grams in 100 c.c. water) to potassium cyanide soln. (60 grams ordinary fused cyanide in 52 c.c. water), until initial white ppt. has just redissolved. When all diazo soln. added, heat on w.-b. until no more nitrogen, and distil with steam. No need to dry, as wanted for next expt. Note odour. Yield 60% . Benzoic Acid from Benzonitrile.—Make up steam distillate to 100 c.c. with water, and boil in reflux appts. with 10 grams caustic soda. When no more ammonia, acidify with hydrochloric acid, and purify and sublime pptd. benzoic acid. Yield 80%. Take m.-pt. by capillary tube method. Test. Compare with stock acid. Qualitative Tests for Benzoic Acid (p. 260).—Ferric chloride in neutral soln. buff pulverulent ppt. After pressing dissolves in a few drops warm cone, hydrochloric acid, which deposits paste of acid on cooling, ltecrystd. from very little hot water forms plates. Odour of acid. Smoky flame. Benzene with soda-lime, which identify by conversion into nitrobenzene. Benzoyl Chloride.—5 grams acid, 10 grams powdered pentachloride (good draught). Distil from test tube, with water out of condenser. Redistil and noteb.-pt. and odour. Try action of cold and hot water on two or three drops, and then add caustic soda and prove benzoate and chloride. Yield 50%. Benzoating Alcohol.—Convert half benzoyl chloride into ethyl benzoate as with mannitol (p. 262) ; equal vol. alcohol; make very slightly alkaline each time, and shake well. Benzamide.—Rest of chloride with powdered ammonium carbonate (2 grams per c.c.) Shake cold product with cold water to remove excess carbonate; recryst. boiling water. Take m.-p.t. Yield 50%. Hydrolyse with caustic soda and prove ammonia and benzoate. Benzoic Acid from Hippuric Acid— Gently boil 3 grams hippuric acid in test tube with 10 c.c. cone, hydrochloric acid for five minutes. Cool. Wash and sublime benzoic acid, and prove by m.-pt. and test. Qualitative Tests for Hippuric Acid (p. 263).—Ferric chloride in neutral soln. brown flocculent ppt. Crystals as with benzoic acid long needles. With soda lime, benzene (which identify) and ammonia. For last, use well-ivashed ferric chloride ppt. [Acetophenone.—Dry distil 20 grams barium benzoate and 10 grams acetate, mixed as in reduction of acetic acid, ch. xiii. Avoid overheating benzoate in drying it. Fractionate product to sept, benzone, and note b.-pt. Shake a little with phenyl-hydrazine acetate and note hydrazone. Oxidise some acetophenone with permanganate, as with acetone, and note carbon dioxide and benzoic acid.] CHAPTER XLIV Benzaldehyde from Benzoic Acid.—Dry distil 5 grams barium benzoate mixed with 2 grams barium formate, as in reduction of acetic acid, chap. xiii. Note silver and rosaniline reactions, and hydrazone—2 or 3 drops distillate, same qty. plienyl-liydrazine dissolved in dil. acetic acid. Oxidation of Benzaldehyde to Benzoic Acid.—Boil 3 c.c. commercial aldehyde with 10 grams bichromate, 5 c.c. cone, sulphuric acid and 50 c.c. water. Cool, filter off benzoic acid, drain, dissolve in dil. caustic soda, filter. Re-dissolve in soda, and reppt. until colourless. Sublime and test. Condensation of Benzaldehyde with Acetone.—2 c.c. benzaldehyde, 4 c.c. acetone, 10 drops ordinary caustic soda soln. diluted with 50 c.c. water. Warm