Laboratory experiments in organic chemistry - ACS Publications

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JOURNAL OF CHEMICAL EDUCATION

350 !%rely the original liternrurc contains may). ctther reliable procedures that have been carefullv worked our, and ofren checkcd in more than one laboratory. I grant that a decision between the categories "Formation" and "Preparation" is a difficult one, but feel that expansion of the second category is a desirable goal. In any case the situation would be improved by freer citation of yields. As it stands, one finds no preparative procedure given for many fairly common compounds and is often confronted with a mass of references to reactions of formation with no indication of which ones have preparative application or proceed to an extent significant of directive eEectects or reaction mechanisms. If the user plans to prepare a batch of material he probably will want toresd the papersin any case; if heseeks quick infarriation for citation in a paper or book, or for solution of a problem, he would much refer to have all available information about the yields. For kxamp~e,no preparative method is indicated for 1- or Zphenylnaphthalene, and some twenty reactions are listed by which each hydrocarbon is formed with no indication of yields other than an occasional comment such as "in smdler yield," "trace!' How good are the other routes? Which ones could be considered for rapid preparation of comprtrison samples? One mode of formation of 2-phenylnaphthalene cited is hy the action of acids on phenylethyleneglycol; actually the mrtster experimentalist Zincke in 1881 reported a yield of 60-70 per cent of very pure hydrocarbon, and Carter and Van Loon in 1938 reported a yield of 78 per cent. The later authors obtained 2phenylnaphthdene in 80-85 per cent yield by acidolysis of the easily prepared a-amino-8-methoxy-8-phenylpropionieacid and describe this as "a satisfactory preparative method for the hydrocarbon." Another entry in Elsevier states that the hydmcarbon was obtained from 2-( A~-cyclohexenyl)-naphthalene "on heating with S a t 240-60""; the statement might have included the comment "(24 per cent yield from 8-bromomphthalene)," for this would indicate the entire route and success of the synthesis. In some instances, for example, 8-nitro-l-naphthylamine, the citation of yields is entirely adequate, but I feel that general strengthening in this direction is desirable. There is both theoretical and practical interest in the ratio of isomem formed on mononitration of 1-nitronaphthaleneand of tetralin; approximate ratios are known and should be included. 1-Amino- and l-bromotetralin are useful intermediates whose preparation has been studied in several laboratories. and ~renarative~moedurrs

with reactions of the methane p u p ) now includes simple ole6ns and benzene. The test reactions of the aldehydes are now combined in one experiment. The monosaccharides and disaccharides are considered together in Experiment 26. The preparation of 2,4dinit~rophenyIhydrazonesas derivatives of aldehydes and ketones is a very welcome addition. Another is the extremely useful, rapid prooedure for acetylrttion of certajn amines in an aqueous medium. Nine new preparative experiments have heen added. Perhaps the most instructive are methyl n-butyl ether, a Williamson synthesis; stearamide, the preparation of an amide via the acyl chloride state; phenacetin, an important drug; terb butylbenzene, an adaptation of the Friedel-Crafts reaction; 2-methyl-2-pentanol, an diphatic Grignard synthesis; DDT, an important insecticide. A few of the most attractive features of this manual are the questions a t the end of each experiment, the complete, explicit directions, the well-balanced choice of test tube and preparative experiments, and the section on materials and reagents required for each experiment. The reviewer feels that the perforations in the pages of the book are unneceasrtry. Obviously, these allow convenient removal of certain pages by the student, presumably for insertion in a laboratory notebook. This practice seems unwise since it destroys, a t least partially, a potential reference book and, also, causes the laboratory notebook to assume the character of a scrapbook. An interesting change in the text is in the spelling of the common verb, distill (previously, distil). The text appears to be free of errors, since only two minor typographical slips were noted. The reviewer cannot refrain from using this opportunity to recommend this volume most highly. It is without a doubt one of the most practicable mrtnualls for elementary courses in organic chemistry. DONALD C. GRECG UNIVERWT~ 0. VERMONT

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STRENGTH OF PLASTICS AND GLASS

R. N. Howard. Research Chemist, Petrocarbon, Ltd., England.

Cleaver-Hume Press, Ltd., London, England-Interscience Publishers, Inc., New York, 1949. viii 245 pp. 108 diagrams. 16 plates. 14 X 23 cm. $5.50.

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LABORATORY EXPERIMENTS IN ORGANIC CHEMISTRY

Tms baok treats the mechanical properties of plastics and glass. It presents the facts clearly and interestingly and gives a. good over-all view of the subject. The various theories are treated sketchily but with references so that the original articles e m be consulted. The terminology is standard and the book should prove very useful to those seeking an orientation in the field of plastics and glass.

Roger Adorns, Professor of Chemistry, University of IUinois, Urbana, Illinois, and John R. Johnson, Professor of Chemistry, Cornell University, Ithaca, New York. Fourth edition. The Macmillan Co., New York, 1949. xiv 525 pp. 30 figs. 10 tables. 14 X 21 cm. $3.25.

HENRY EYRING

U~rv~nsm OPr UTAH SALTL ~ s a CITT. UTAB

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T m foudh edition of this well-known laboretory manual is, in essence, quite similar to the third edition. It contains several distinct improvements, not the least being its more attractive format. Although the adjective, elementary, has been dropped from the tifle, this revision, as before, is a manual for beginning students. Some of the more notable additions and rearrangements should be mentioned. The text incorporated in the 6rst eight experiments on laboratory operations has been expanded. Two of the several alterations in this section of the manual are: (1) the determination of boiling points precedes the determination of melting points, (2) a short discussion of sublimation is added to the section on crystallization. Experiment 9 (formerly dealing

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ELECTRON MICROSCOPY

Ralph W. G. Wyckoff, Laboratory of Physical Biology, Experimental Biolagy and Medicine Institute, National Institute of Health, Bethesda, Maryland. Interscience Publishers, Inc., New York, 1949. 248 pp. 202 illustrations. 16 X 24 om. $5. 'l'n~sattractive Im,k will be u~clcomeduut only by time working in the field of rlwtron microaeopy, hut d30, and mninlp, by clreniistq and i,ihgistr at large who wi41 to have a aummnrv of the present state of the art and science of electron m i o r ~ s c ~ ~ ~ , with particular regard to the kinds of problem which now can be and are being attacked with the electron microscope. Four early chapters, comprising almost half of the book, are