March, 1949
NOTES
1133
In order to avoid even a temporary excess of - 2 . 2 . The effect of refractive index on the position and size of the light spot was measured directly oxidant, the order of addition of reagents has by photographing the spot near the face of the been reversed. That is, a slurry of lead tetraacephototube. A 30% decrease in area of the spot was tate (1.0 mole) in benzene was added slowly to a observed when a 10-cm. cell filled with water was in- stirred benzene solution of glycerol a-phenyl troduced into the beam. Further successive de- ether2 (1.0 mole). This addition was accomcreases in area of the order of 5% were observed plished during tu. two hours while the reaction when the water (R.T. = 1.33) was replaced first mixture was stirred vigorously a t a temperature of by dioxane (1.42) and then by benzene (1.50) 20-25’. After isolation as previously described,‘ and small changes in the positions of the spots were the product was fractionated through a 24-in. also noticed. Widmer column, b. p. 82-83’(4-5 mm.). The Although for the 5 and 10 cm. cells the differ- aldehyde thus obtained represented a yield of 60% ences in matching factors may be large and quite of theory; ~ O 1.5360, D d’O4 1.1305 (cf. Huntress D d Z 1 ,1.1310). Molecvariable with refractive index, good agreement can and Mulliken3 T Z ~ * 1.5380, be obtained using both phototubes as long as the ular refraction, 37.54 (found), 37.20 (calcd.). matching factors a t a given wave length are obThe value of this simple modification has been tained separately for each phototube and each confirmed by one of us4 in the case of other sensiliquid used. In this way discontinuities in absorp- tive aldehydes. tion curves, which are sometimes obtained a t the (2) Supplied through courtesy of the Miner Laboratories, Chicago, point where the tubes are interchanged, can be Ill. (3) E. H. Huntress and S. P. Mulliken, “Identification of Pure eliminated. The source of error discussed is par- Organic I,” John Wiley and Sons, Inc., New ticularly important when solutions varying widely York, N .Compounds-Order Y . , 1941, p. 66. in refractive index are matched against one sol(4) Henry R. Mahler, Thesis. University of California, 1948. vent. INDUSTRIALRESEARCH DIVISION The effect was also determined for 1-cm. cells TEXASRESEARCH FOUNDATION RECEIVED NOVEMBER 15, 1948 which are used by the majority of investigators. RENNER,TEXAS The difference in the matching factors for several of these cells changed by 0.1-0.3% (in terms of transmission) when benzene in the cells was re- Ascaridole in Oil of Chenopodium. 111.’ The Characterization of Ascaridole placed by water. These amounts become appreciable in terms of optical density only when very BY H. HARRYSZMANT AND ALFRED HALPERN low absorptions are being measured. In connection with the investigation of the For work of the highest accuracy, matching factors should be rechecked with any change of op- chemistry of ascaridole in progress in our Laboraerating conditions whatsoever. Due to the zonal tories1P2i t was desirable to reexamine the physical variations in spectral sensitivity of phototubes, properties of ascaridole in view of the discrepan~ physical properdifferences in matching factors may be expected cies noted in the l i t e r a t ~ r e .The whenever the effective area of the phototube ties of ascaridole are of particular importance since illuminated is altered in any way. In addition to no solid derivative of ascaridole is known. Oil of chenopodium4 was fractionated using an the effect of refractive index, such changes may all-glass system equipped with a Vigreux column. be brought about by slight localized variations in transmission of the absorption cells due to striae, The physical properties and yields of the various scratches, etc., and when cells are shifted in orien- fractions are summarized in Table I. The fractions obtained from the preliminary tation with respect to the phototubes. distillation above, were analyzed for ascaridole The authors wish to acknowledge the assistance content according to the method of Cocking and of Mr. J. C. Hyde. Hymas5 and the results are included in Table I . DEFENCE RESEARCH CHEMICAL LABORATORIES A portion of fraction “C,” which analyzed iodoOTTAWA, ONTARIO RECEIVED SEPTEMBER 11, 1948 metrically for pure ascaridole, was subjected to a careful fractionation in a two-foot glass-helicesPhenoxyacetaldehyde packed column. The physical properties of the fractions obtained during this refractionation are BY ROBERT J. SPEERAND HENRYR. MAHLER reported in Table 11. Hatch and Nesbittl have reported the synthesis (1) For paper I1 in this series see Halpern, J . A m . P h a r m . Assocn , of phenoxyacetaldehyde in 45y0 yield by the lead 37,465 (1948). (2) Halpern, i b i d . , 87, 161-165 (1948). tetraacetate oxidation of glycerol a-phenyl ether. (3) Henry and Paget, J. Chcm. Sor., 119, 1714 (1921); Paget. In connection with the radiochemical program of ihid., 829-833 (1938) ; Paget, Analyst, 51, 180-186 (1930); Khavin, this Laboratory, the aldehyde in question has been U k r a i n . Gosudarsf. Inst Ekspll. Farm. (Kharkoe.), Konsul’lalsionnyr prepared as an intermediate for certain labeled M a f c r i a l y 1939, No. 6, 165, cf. C. A , 86, 2997 (1942); Janot and amino acids. It has been found that a modifica- Chaigueau, Compt. r e n d , 214, 746-747 (1942); Thorns and Dobke, P h a r n . , 268, 128-137 (1930). tion of the above preparative technique results Arch. (4) Oil of Chenopodium meeting all of the N . F. VI11 requirements in an improved yield. was obtained from Magnus, Mabee and Reynard, Inc., New York. (1) L. F. Hatch and S. S. Nesbitt, Tars JOURNAL, 61. 39 (1946).
(5) Cocking and Hymas, Analyst, 55, 183 (1830).
