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.

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    CHAPTER XLI Phenol from Benzene-Sidphonate.—8 grams sulphonate, 40 grams caustic potash, 4 c.c. water. Stir well with thick iron wire. Thermometer bulb must be protected with silver cap, or else placed in sand under dish. Distil phenol from test tube after removing ether. Note b.-pt. Test. Yield 50%. Phenol from Aniline.—10 grams aniline to 10 c.c. cone, sulphuric acid in 90 c.c. water. 10 grams sodium nitrite in 40 c.c. water until paper blue (chap. x.). Prove nitrogen. Note b.-pt. and test. Yield 85%. Qualitative Tests for Phenol (p. 251).—Odour. Tribromophenol, and re- conversion into phenol. Blue with bleaching solution. Liebermaun’s blue; about 4 gram sodium nitrite in 5 c.c. cone, sulphuric acid ; two or three drops of phenol soln. to this. Picric acid : warm with little cone, nitric- sulphuric acid, pour cool into water; yellow, darkened by alkali, purple with cyanide. CHAPTER XL1I [Diazobenzene Nitrate.—10 c.c. aniline in cold mixture of 8 c.c. cone, nitric acid and 15 c.c. water. Drain cryst. mass and wash with small qties. of cold water until only slightly acid. (Trioxide from 25 grams white arsenic, lumps, not powder, and 25 c.c. cone, nitric acid ; warmed on w.-b.; gas through empty bottle to deposit acid spray.) Keep aniline paste ice-cold. Diazo crystals may not appear at once ; keep in ice, and wait two hours before trying again (stir occasionally). Decompose with water (note nitro- phenol on steam dist.) ; alcohol; hydrochloric acid ; potassium iodide; and bromine for perbromide. Explode a little.] Bromobrmzene from Aniline by Diazo-Reaction.—5 c.c. aniline in hydro- bromic acid from bromobenzene prepu., diluted to 60 c.c. Cool in ice, and add nitrite soln. as with phenol. Then add gradually moist pptd. copper from 10 grams zinc dust and 40 grams copper sulphate. (See chap. xiv. zinc methyl note). When reaction over, steam dist. and dry. Compare product with bromination product. B.-pt.; sp.-gr. Yield 75%. Elimination of Amido-Group from Aniline.—5 c.c. aniline in mixture of 15 c.c. cone, hydrochloric acid and 32 c.c. water; ice-cold. Diazotise cryst. magma with nitrite as before, and add 40 c.c. ice-cold 25% caustic sodi powder soln., keeping cold. Pour this product gradually through condenser into reflux appts. containing at ordinary temperature soln. of 23 grams stannus chloride in 55 c.c. water to which about 25% caustic soda soln. has been added until ppt. has practically redissolved. When evolution of nitrogen ceases, steam distil, dry and redistil. Note odour, b.-pt. and m.-pt. of benzene. Yield 80%. Phenyl-hydrazine.—Ice-cold paste of 14 c.c. aniline and 135 c.c. cone, hydrochloric acid diazotised with 20% nitrite (tests on dilute samples), and ice-cold soln. of 65 grams stannous chloride in 60 c.c. cone, hydrochloric acid added. Keep cold, wait half an hour before filtering. Note b.-pt. Yield 80% . Convert some into glucosazone and benzene (below). Reducing Action of Phenyl-hydrazine.—Boil two or three drops with alkaline copper tartrate. Note nitrogen and red oxide. Reduction of Phenyl-hydrazine to Benzene.—-Run soln. of 4 grams hydra- zine in 9 c.c. B.P. acetic acid and 25 c.c. water, into copper sulphate soln. (20 grams in 60 c.c.) boiling in reflux appts. Note evolution of nitrogen (prove), and distil off benzene with steam. Yield 70% . Identify by odour and conversion into nitrobenzene (odour). CHAPTER XLIII Conversion of Benzoic Acid into Benzene.—Dry distil intimately ground mixture of 5 grams benzoic acid, 5 grams soda lime, and 5 grams fine iron