3527
NOTES
July, 1961 and more reliable than the reduction with zinc dust and water, described by Gabriel and Coleman. An attem t was also made to reduce 4-methyl-2,6-dichloropuriner by the same method. According t o E. Fischer,6 however, the expected 7-methyl-2-chloropurine is not stable in contact with dilute alkali, but is converted into 7-methyl-2-hydroxypurine (m.p. 323’) and an unidentified substance of the composition CsHTClNd (m.p. 251’). Indeed, two substances of these melting points, respectively, were isolated, when the reaction product was worked up.
calibration solution, and the cell may readily be checked for constancy of “cell constant” over a range of concentration. Table I provides these data, obtained by tabular and graphical integration of the results of Gosting and of Harned and Nuttall according to equation (2). INTEGRAL
( 5 ) E. Fischer, ibid., SO, 2400 (1897). (6) E. Fischer, ibid., Si, 2660 (1898).
DANIELSIEFFRESEARCH INSTITUTE WEIZMANNINSTITUTE OF SCIENCE REHOVOTH, ISRAEL RECEIVED MARCH1, 1951
Integral Diffusion Coefficients of Potassium Chloride Solutions for Calibration of Diaphragm Cells BY R. H. STOKES
Do -
:soc
=c
TABLE I DIFFUSIONC O E F F I C I E N T S
0.000 ,001 ,002 .003 ,005 ,007 .01 .02 .03
R I D E SOLUTIONS AT
O F POTASSIUM C H L O -
25”
Ddc. ( c in moles/liter, Doin cm.2 sec-’ X 10-6)
bo 1.996 1.974 1.966 1.960 1.951 1.945 1.938 1.920 1.908
C
Do
c
0.05 .07 .1 .2 .3 .5 .7 1.0 1.2
1.893 1.883 1.873 1.857 1.850 1.848 1.851 1.859 1.866
1.4 1.6 1.8 2.0 2.5 3.0 3.5 3.9
-
DO 1.874 1.882 1.892 1.901 1.927 1.953 1.979
Gosting’ has recently obtained absolute meas2.000 urements of the differential diffusion coefficients of potassium chloride in water a t 25’ from 0.1 N to 3.9 N by the Goiiy interference technique. TABLE I1 Harned and Nuttall,2 using a conductimetric FURTHER DIAPHRAGM CELLMEASUREMENTS ON POTASSIUM method, have also obtained absolute values in the CHLORIDE SOLUTIONS AT 25” range 0.00125 N to 0.5 N , which are in extraordicm’ in moIes/liter, B,”,, in cm.2 sec.-1 x 10-5 narily good agreement with those of Gosting in the Thus the combined overlapping part of the range. ClU’ D h’ CIU’ D:d data may be used with complete confidence for 0.3877 1.853 0.8721 1.854 testing and calibrating other types of diffusion .3911 1.849 .8344 1.854 apparatus. For diaphragm-cell measurements, ,6310 1.842 .8820 1.851 however, i t is convenient to start the diffusion with .6188 1.851 .8972 1.852 solution on one side of the diaphragm and pure ,6462 1.851 water on the other,3 in which case the diffusion In the figure, the data of Table I are compared coefficienJ obtained is a rather complicated average value, D, called the “diaphragm-cell integral graphically with the diaphragm-cell results previously reported by the writer.3 (The open coefficient.” Under these conditions, denoting the mean of the circles on this graph represent the means of each initial and final concentrations on the solution side pair of approximately duplicate runs reported in by cm’, and the mean concentration on the other Table I11 of reference (3) .) It is clear that, though side by cmb (which is half the final concentration the average deviation of the points from the standon the side which was initially pure water), i t has ard curve is less than 0.3%, most of this deviation is due to the points near the minimum. As the been shown3 that measurements represented by these points hapD ! , ~ , ) = D- 5; [B- D~cm,,)l ( l a ) Cm or Here the quantity D!c) is the “integral diffusion coefficient for a run of vanishingly short duration” between the concentration c and pure water, given by
D being the true differential diffusion coeflicient as measured for example by the optical or conductimetric methods. It is consequently very useful in diaphragm-cell work to have a table of values of the quantity 0:’) for all values of c for the calibration solution, as it is then unnecessary to select a particular length of run or initial concentration of the (1) L. J. Gosting,T H IJOURNAL, ~ 72, 4418 (1960). 12) H. S . H a r n e d a n d R. L. Nuttall, ibid., 69, 736 (1947); 71, 1460 1940). (3) R. H. Stokes, ibid., 72, 763, 2243 (1950).
184
-
0
0
1
pened to be among the earliest made in the development of the magnetically-stirred diaphrngincell, and were possibly not of the standard of precision obtained later, it seemed worthwhile to make some further measurements in this region. The technique used was closely similar to that described in reference-(3), and gave the results in Table 11, where the D values have been converted to Do values by the use of equation ( l a ) . The means of the four new measurements using iiiitiallv 1 -Ypotassium chloride solution, the three using initially 0.7 N solution and the two using initially 0.43 14' solution are shown as filled circles in the figure. I t is evident that the original rneasurenients near the minimuin were in error by two or three times the estimated experimental error of 0.2Cr,. In consequence of this, the smooth curve drawn through the open circles was appreciably different in shape near the minimum from what i t should have been. Hence the differential diffusion coefficients obtained from i t and reported in reference (3) differ in some cases by nearly 1% from those reported by Gosting.' It would appear that it1 using the diaphragm-cell method especially great care should be taken in regions of rapid change of slope of the integral diffusion coefficient. Ll'ith this reservation it is clear that the diaphragnicell ineasuremerits agree very well with the new absolute data obtaitied by Gosting. In coticlusioii it would perhaps be as well to mention that in calibrating diaphragm-cells with the use of Table I, i t is unwise to use any solution below 0.1 LV in concentration a t the start of the experiment, as a t lower concentrations the anomalous surface-transport effect3 becomes prominent. CHEMISTRY DEPARTMENT UNIVERSITY OF WESTERNAUSTRALIA NRDLAVDS, \\' .A RFXEIVEIIFKIRUARY 23, 1951
tyl ether has been reported.? It was prepared by catalytic dehydration of a mixture of the two corrcsponding alcohols. The boiling point (108-110') was the only property given. We have, therefore, prepared the four allyl butyl ethers and determined some of their properties. Experimental
Preparation and Properties of Allyl Butyl Ethers.-All ethers were prepared in the same manner. One t o one and a half moles of butyl alcohol in 200 to 300 cc. of xylene was placed in a 1-liter three-necked flask furnished with a condenser, a stirrer and a separatory funnel. An equimolar quantity of sodium was gradually added to the solution. After the entire amount of sodium had been added, thc reaction slowed down somewhat owing to coating of alkosidc on the metal. A t this point, the bath temperature w i . ; raised to about 115' and the stirrer was started. The sodium melted, and the reaction proceeded. After all thc sodium had disappeared, the flask was cooled to room temperature, and an equimolar amount of allyl bromide was gradually added through the separatory funnel. When the entire amount of allyl bromide had been added, the bath temperature was raised to 110-115° and kept a t this temperature for about five hours. If any blue color remained a t this time, methanol was added until the blue color disappeared. The mixture was then washed with water, dried and distilled. The theoretical amounts of allyl bromide were used for convenience of procedure a t the expense of better yields. Under the conditions of the experiments, the yields were about 25y0 for the allyl t-butyl ether, 40% for the ethrr of isobutyl alcohol anti 607, for the ethers of nnrm:il : i i i ( l sccondary butyl alcohols. 'i'al>l(>I gives the properties of the four cllic~s. 'r.&III.IZ
PROPERTIES OF
Allyl (b& Wijs), Butyl (theory, group 36.0%) Normal 36.0 Secondary 36.0 Is0 36.0 Tertiary 3 6 . 1 0
I
ALLYLIjUTYI,
T?TfIERS
B.P., OC. bfm. dno, 1 1 7 . 8 - 1 1 8 . 0 763 0 . 7 8 2 9
Mole refraction Calcd.'l Found 1.4057 35.87 33.80
1 0 7 . 1 - 1 0 7 . 4 762 1 0 6 . 6 - 1 0 7 . 0 749 9 9 . 2 - 1 0 0 . 0 760
1.4023 1.4008 1.4011
,7792 .7735 ,7770
it*o~
35.70 35.90 3.5.83
35.70 35.83 38.71
A . I . Vogel, J . Ckem. SOL.,1842 (1948).
- . ______.
(4) A. Mailhe and F. de Codon,
Bull. SOC. chim., 141 97, 328 (1920).
Allyl Butyl Ethers' EASTERN REGIONAL RESEARCH LABORATORY RECEIVED hIARCH 1, 1951 1 3 E. ~ A . TALLET, ilss S.IIUSTERASD E. YASOVSKY PIIILADELPHIA 18, P E X X A . I t has been suggested that in our work 011 allyl starch,2 one of the butyl alcohols might serve as a reaction solvent. The obvious objection to the use of alcohols in this reaction is the formation of ethers a t the expense of allyl halide used for the main reaction. When an attempt was made to separate the allyl butyl ethers by fractionation of the organic layer of the reaction, azeotropes of the ether and alcohol were obtained.:' Since attempts to separate the two by extracting the butyl alcohols with water were unsuccessful, a t least in the case of normal and isobutyl alcohols, i t was tleetned advisable to learn iiiore about the properties of pure allyl butyl ethers. In the literature, only the allyl isobu(1) Contribution frnm oite o f the lnhoratories of the Bureau of .\gricultuml and 1tidiistri:d Clicuii~try, :\yririiltural Research Administratlorl, C-niterl StiitCq Pep:irtlncnt o f .\grirulti,re. Article not copyrighted. (2) P. L. Nichols, J r . . R.h l Hamilton. Lee 1'.Smith and E. Yariovs k y , l n d . Eng. Chrtwz., 37, 201 (1Y9.5): It. A. T d l e y , R. M. Hamilton, 1. I f . Schwartz, C. A. Browii and I*; Y a n o w k y , U. S. Dept. Agr., terii Regional Research LnHur. Agr. and Ind. Chern., AIC-110. lmratory) Pel). 1917 ifroressed). 1 3 1 C f . D N . Kursmov itnil 0. M. Shemyakina. Doklady - 4 k n d . \'orrk Y .S .S K , 62, :311 ::!'it l $ l 4 8 ~ , (, ' \., 43, 3 l J O h I ! r l R )
,
Unsaturated Lactones. 11. The Relationship Between Chemical Constitution and Absorption Spectra in a Group of Crotonolactonesl BY F.N'. SCHCELER A N D CALVIN HANSA I n a previous report2 we had occasion to discuss the relationship between chemical constitution and the ultraviolet absorption spectra in a group of unsaturated azlactone derivatives. I n the present coniinunication we have extended this discussion to include a series of crotonolactones which derive part oi their interest from the close chemical and physical similarities that they hold with respect to the unsaturated azlactones. Out of a group of twenty crotonola~tones~ synthesized during this investigation four were re(1) This work was aided b y a xrnnt from the U. S. Public Health Service. 131 F. W. Schireler and S . C. W'ang, l m s JOURNAL,73,2220 (1950). ( 3 ) These together with the azlactones and a group of related materials have been studied for cardiac activity and reported elsewhere. P. W. Schueler and C 1T;inna. .t,flz. l i i l r u i i Phnvmacodyn. rl P'herafiir, i n press, lq.51.
