2586
NOTES
a formula for the oxide of Pa206, the half-life of the protactinium is calculated, using the relation XT = loge*, where X is the disintegration constant and T is the half-life. Since the two samples give the same half-life value within experimental error, the rather more precise value of sample 2 is taken, namely, 34,300 * 300 years. The largest uncertainty in the measurements may actually be the structure of the ignited protactinium oxide. We are indebted to Professor W. H. Zachariasen for a study of the X-ray structure of the powder. Although the patterns obtained are complex, there seems t o be evidence for a possible Pa02 structure. If the composition of the ignited material is actually the dioxide composition, the half-life value given would be low by approximately 3%.
Vol. 71
conditions is Pa02 rather than the expected Paz06. CHEMISTRY DIVISION ARGONNE NATIONAL LABORATORY CHICAGO, ILL. RECEIVED MARCH7, 1949
IV. Addition of Malonate Systems to Alkyl Substituted Acroleins’
1,CAddition Reactions.
BY DONALD T. WARNER AND OWENA. MOE
I n previous publication^^^^ the 1,4-addition of malonate systems to acrolein has been disclosed. The present report concerns the l14-addition of malonate systems to alkyl substituted acroleins such as crotonaldehyde and methacrolein (amethylacrolein). The addition of ethyl malonate] ethyl ethylmalonate, ethyl acetamidomalonate and ethyl Discussion acetamidocyanoacetate to methacrolein and croThe presently reported value of the Pa231 tonaldehyde proceeded to yield the corresponding half-life, 34,300 years, is higher than any ap- aldehydo compounds. The aldehydo compounds pearing in the literature. The closest corre- were characterized either as the phenylhydrazones spondence is found with the 1932 value of von or as the 2,4-dinitrophenylhydrazones. Grosse, namely, 32,000 years4 This value was R’ R’ obtained from presumedly pure macro amounts R-A-COOEt + R-L-COOEt of the isotope; the values given in the earlier I I literature are based on growth into purified CHR* H uranium of the protactinium. These early deterI minations depend on measuring current intenR3 CHR3 sities in an alpha electroscope, knowing the I RzcH=L-cHO -+ CHO number of ion pairs produced for both protactinium alphas and U238 alphas, and knowing The catalytic reduction of y-acetamido- y1y-diprecisely the ratio of activity of U236and U238in carbethoxy-a-methylbutyraldehyde yielded the natural uranium. The method is beset with corresponding carbinol (4-acetamido-4,4-dicarcorrections and imperfectly known constants, and bethoxy-2-methyl-1-butanol)which may prove to is inherently inaccurate. Correction of the be of interest in the synthesis of 6-hydro~yleucine.~ original data with present values of the constants Farmer and Mehta5 reported the reaction beinvolved fails to raise the values to the level tween ethyl malonate and crotonaldehyde in the reported here, although a certain amount of con- presence of a “fractional molecular proportion” sistency between different determinations by of sodium ethoxide a t 0’. By this means, these similar techniques can be found. The deter- investigators attempted to show that the formamination of von Grosse with macro amounts of tion of the double addition product I1 from crothe isotope eliminated some sources of error, but the determination again was dependent upon knowledge of the number of ion pairs produced per alpha particle, and comparison with alpha CH1CH=CH-CHCH emission of uranium as measured in an electroI scope. A source of error unknown to von Grosse I CHCOOEt is the fact that one-eighth the alpha particles I emitted by protactinium differ in energy from the COOEt rest by some 300 kev.8 The determination by COOEt I direct counting of alpha particles, as carried out CH1CH-CH2-CH-CHCOOEt in our experiments, is therefore the least questionI I able of the procedures used. The uncertainty CHCOOEt CHCOOEt of the experimental value is probably well below I I COOEt COOEt 1%. A revision of approximately 3% must be I1 made in the value if i t is shown that the pro(1) Paper No. 95, Journal Series, General Mills, Inc., Research tactinium oxide obtained under our experimental amounts, so no correction was made. Assuming Department. (2) Moe and Warner, THIS JOURNAL, TO, 2763 (1948). (8) F. L. Clark, H. J. Spencer-Palmer and R. N. Woodward, Report Br-522 (1944); T.San-Tsiang, M. Bachelet and 0.Bousnietes, Phys. Res., 59, 3Q (1046).
(3) Warner and Moe, ibid., TO, 3470 (1948). (4) Dakin, J . B i d . Chcm., 164, 652 (1944). (5) Farmer and Mehta, 6.Chrm. S O L , 2561 (1831).
2587
NEWCOMPOUNDS
July, 1949
TABLE I COOEt
I SUBSTITUTED BUTYRALDEHYDES A N D DERIVATIVES R-C-CH-CHCHO
I 1
R1 R 2 Aldehydes
R H Et CHaCONH CHsCONH H Et CHaCONH CHaCONH
R' COOEt COOEt COOEt CN COOEt COOEt COOEt CN
R2 Ra H
H H H Me Me Me Me
Me Me Me Me H H H H
Yield,
7
z,C.p. or b.Mm.p.
... .., ,. 60.45 59.90 8.59 ,, ... ., 55.00 55.42 6.66 .1 57.36 56.96 7.88 .6-0.7 , , . ,, . 54.34 54.07 7.37 55.00 55.03 6.66
42d 76-77a 0.05 25 77-80a 0.07
loo*
58' 112-113 12 80-83Q 38 80-92a 75 88-89 75 175-177
,
-Analyses, %Carbon Hydrogen Mi p., Calcd. Found Calcd. Found C.
.
.
.
,
..
8.76 ,.. 6.83' 7.82 ... 7.48* 6.43'
91-92 79-81 147c 193 90-91 116 150 201
I
R3
-
2,4-Dinitrophenylhydrazone-Analyses, % ' Carbon Hydrogen Nitrogen Calcd. Found Calcd.Found Calcd. Found
c
49.73 52.06 60.46 48.57 49.73 52.05 48.82 48.57
49.78 52.05 60.62 48.80 49.98 51.70 48.68 48.85
5.40 5.98 7.21 4.76 5.40 5.98 5.39 4.76
5.52 6.09 7.50 4.59 5.58 5.94 5.34 4.54
13.65 12.78 11.14' 20.00 13.65 12.78 14.98 20.00
14.04 13.11 11.48' 19.88 13.83 12.75 15.23 20.15
* Crude oil not distilled. This product was the phenylhydrazone a Liquid aldehydes, purified by distillation. Based on crude product, m. p. = Base! on crude product, b. p. = 86-110° (0.2-0.4 mm.). e Based on crude oil, YON; calcd. 4.88:found, 4.88. * %N; calcd. 11.66; found, 11.91. 89-95 . ' %N; calcd. 11.66; found, 11.76.
'
ton ylidene malonic ester proceeded through the intermediate crotonylidene dimalonic ester I. However, they reported that the components of the reaction mixture could not be resolved by fractional distillation. Previously, Farmer and Healy6 had attempted to prepare this crotonylidene dimalonic ester by the addition of malonic ester to crotonylid'ene malonic ester without success.
zations from benzene, gave yields of 20 to 60%. We have now obtained reproducible good yields of this substance by the action of iodine and sodium ethylate on 4-bromobenzyl cyanide, following the procedure described by Chalanay and Knoevenagel. In this way a yield of 38-40 g. (78 to 82%) of a practically pure, light yellow product, m. p. 212', was obtained from 49 g. of the bromobenzyl cyanide. Recrystallized from benzene, almost colorless crystals were obtained, m. p. 214') showing no depression of the melting point when mixed with an authentic sample prepared according to reference 1.
Experimental Syntheses of the Aldehydo Compounds .-The aldehydo compounds in which R = CHsCONH were prepared essentially as described in an earlier publication.2 The aldehydo compounds in which R = E t or H were prepared according to the general procedure described previously. a The physical constants and derivatives of these products (2) Chalanay and Knoevenagel, ibid., 26, 285 (1892). are described in Table 1. Reduction of -pAcetamido-r,y-dicarbethoxy-a-methyl- DEPARTMENT OF ORGANIC CHEMISTRY butyraldehyde.-The crude aldehydo compound (25 9.) THEHEBREW UNIVERSITY RECEIVED FEBRUARY 23, 1949 was dissolved in 100 cc. of absolute ethanol. Raney JERUSALEM, ISRAEL nickel (5 g.) was added and the reduction was carried out a t 100' with an initial hydrogen pressure of 1500 pounds. After the reduction was complete, the catalyst was removed by filtration and the filtrate was concentrated a t reduced pressure to yield a residual oil which resisted NEW COMPOUNDS crystallization. The carbinol was characterized as its 3,5dinitrobenzoate which melted a t 123-124 O after crystallization from absolute ethanol. 2,4-Diketo -0ctahydro-2 -pyrido ( 1,2-a)pyrimidine Anal. Calcd. for CnoHzjO1INa: C, 49.69; H , 5.21; N, A mixture of 5 g. of 2,4-diketo-3,4-dihydro-Z-pyrido8.69. Found: C,49.72; H,,5.28; N,8.66. (1,Z-a)pyrimidinel and 0.16 g. of Adams catalyst in 200 ml. of ethanol was shaken a t 60" under 3 atm. of hydro(6) Farmer and Healy, J . Chem. Soc., 1065 (1927). gen. After three hours the calculated amount of hydrogen CHEMICAL LABORATORIES was absorbed. The catalyst and solvent were removed, GENERAL MILLS,INC. and the residue, on crystallization from dioxane-ether, MINNEAPOLIS, MINNESOTARECEIVED JANUARY 28, 1949 yiel$d 3.5 g. (71y0) of light yellow crystals, m. p. 170173 . A sample prepared for analysis by vacuum sublimation was white and melted a t 174.0 to 174.5". 4,4 '-Dibromo-a,a '-dicyanostilbene Anal. Calcd. for CsH12iY~02: C, 57.14; H , 7.14. Found: C, 57.23; H , 7.37. BY MOSHEWEIZMANN AND SAULPATAI Although 2,4-diketo-octahydro-2-pyrido(l,2-a)pyrimiWislicenus and Elvertl state that 4,4'-dibrorno- dine bears a certain formal resemblance to known bara, at-dicyanostilbene can be prepared from $- biturate drugs, i t was found on intraperitoneal administration of the compound to mice that the only noticeable bromophenylisonitroacetonitrilesodium and dilute physiological symptom was hypersensitivity to pain.* ~~~
~~~~~
sulfuric acid a t room temperature in almost quantitative yield. We have tried in vain to duplicate these results using 2.5, 5, 10, 15 and 25% dilute sulfuric acid. In all cases the crude product was either a reddish oil or a sticky mass which, after several recrystalli(1) Wislicenus and Blvert, Bcr., 41, 4126 (IQOS)'
~
~
~
~
~~
DEPARTMENT OF CHEMISTRY UNIVERSITY OF ROCHESTER V. BOEKELHEIDE ROCHESTER, NEW YORK J, FIGUERAS RECEIVED FEBRUARY 21, 1949 (1) Tchichibabin, Bcr., 6'7, 1168 (1924). (2) The physiological tests were conducted by F. M. Berger, M.D., Department of Pediatrics, University of Rochester Medical School'
