2790
GrLmIN, JONES, BINDSCHADLER, BLUXE,KARMAS,LhRTIN, NOBIS,
AND ~ O E M A N
Vol. 7s
~~~-~-M~thylcyclopentanol.-The 2-methylc~-clopentanol dinitrophenylhpdrazone melted a t 156.6-157.0". A mixture obtained by reduction of 2-methylcyclopentanone with so- of this derivative and the 2,4-dinitrophenylhydrazoneof 2dium and ether was converted t o the p-toluenesulfonate by meth~-lcyclopentanone,m.p. 159.0-159.4O, melted a t 157.0the general method of TipsonZoexcept t h a t the reaction mix157.6'. The semicarbazone melted a t 172.8-174.3'. A ture was kept a t 0" for three hours. Thep-toluenesulfonate mixture of this material and authentic 2-methylcyclopenwas recrystallized t o constant melting point from 30-60" tanone semicarbazone, m.p. 175.4-17A.2°, melted a t 171.8petroleum ether21; C Q . 42% yields of trans-2-methylcyclo175.9'. pentyl $-toluenesulfonate melting at 33.8-34.5' (lit.11a Analysis of Mixtures of cis- and trans-2-Methylcyclopen34.4") were obtained. tano1.-Determination of the isomeric composition of mixA mixture of 25.4 g. (0.10 mole) of tinns-2-methylcyclotures of cis- and tinns-2-methylcyclopentanolwas carrietl pentyl P-toluenesulfonate, 10.9 g . (0.11 mole) of freshl>- out by converting the samples t o the 3,5-dinitrobenzoatc fused potassium acetate and 117 ml. of acetic anhydride free derivatives and determining the composition of the derivnof acetic acidz2was heated in an oil-bath at RO-10O0 under tives from the binary melting point diagram. Data used reflux with stirring for 48 hours. It was then cooled and in constructing the melting point diagram are shown i n d d e d t o 3880 ml. of 2 . 5 N sodium hydroxide. After refluxTable I . ing for one hour with stirring the alcohol was removed by TABLE I azeotropic distillation with water. About 3 1. of distillate was collected. T h e distillate was saturated with potasTHE b l E L T I N C P O I N T S O F ?IIIXTURES O F cis- A N D t 7 0 n S - 2 siuni carbonate and extracted with ether. T h e ether exMETHYLCYCLOPESTYL 3,~-~ISITI~Ol~E~ZOATES tracts were dried over potassium carbonate, the ether was so cis M . p , oc. (7r cis 1I.P.' o c . removed through a short Vigreux column and the cis-20.0 86.0-87.0 63 3 69.3--71.5 meth>-lcyclopentanolwas distilled. A 22Y0 yield of mate11.2 81.2-82 4 ro.1 73 3-75 8 rial boiling a t ca. 68' (55 mm.1 was obtained. This material was purified by conversion t o the 3,5-dini26.1 74 8--77 2 93 1 82.1-83 6 trobenzoate, recrystallization t o constant melting poiut, re37.1 70.4-72 7 100.0 85.8-86 0 duction with lithium aluminum hydride and fractionation as 49.2 6 5 2-66.3 described above for tians-2-meth~-lcyclopentariol. cis-2Methylcyclopentanol boiled a t ca. 75' (45 mni.), n Z 5 ~ Synthetic mixtures of cis- and ti.ans-2-methylcyclopen1.4533, dZ540.9267; M R calcd. 29.24, X R found 29.23. tanol containing 14.0, 32.8 and 5!.9% cis gave 3.5-dinitroAnal. Calcd. for C6HI20: C , 71.94; H , 12.05. Found: benzoates melting a t 81.0-81.9 , 73.8-75.2", and 68.8C, 71.74; H , 11.99. 70.2', respectively, indicating t h a t they contained 13, 30 T h e p-nitrobenzoate melted a t 38.7-1F).OD (lit.11n5 2 . 5 ' ) . and 62% cis-2-meth~~lcyclopentanol. Addition of 5 and 21 yo tre~zs-2-meth~-lcyclopentyl p-nitroThe melting point of the 3,5-dinitrobenzoate melting a t benzoate lowered t h e melting point only 0.5 and 0.2', rc- 65.2-67.8" was raised by the addition of a small amount of spectively; addition of 5170 raised it t o 52.6-53.6'. c-is-3,5-dinitrobenzoate and lowered by the addition of a small The 3.5-dinitrobenzoate melted at 85.8-86.0" (lit. 67.7',11* amount of traizs-3,.i-dinitrobenzoate; therefore this ninteri:~l 66-67 ' l l b 1. is 58% cis. Lithium Aluminum Hydride Reduction of 2-Methylcyclod n n i . Calcd. for C,, m n l i - < i r t i i fcir lwriili,tc,
Twenty-seven uranium( 11.) 1,3-tii-
to inorganic derivatives, our approach to the problem was to prepare and study new organic uranium compounds. Some prior work in this Laboratory had already indicated t h a t simple organometallic derivatives like tetramethyluranium, if they existed a t all, were mtreinely unstable, and their isolation offered little chance o f success. Therefore, attentiori WAS tlirectcti t o w a d the prcparatioii of other t y l ~ c s o f o i y ' i i i i v cc~iiii~ounds liiikctl t o uraiiiuiii
June 20, 1956
2791
1,3-DICARBONYL URANIUM CHELATES
TABLE I URANIUM( IV) DICARBONYL COMPOUNDS U(RC0CHCOR')r Reference diketone d
d d d
d
d d
Yield,
% 85 50 58 54 48 62 32
d
d d d d d
20 74 12 45 75
d E
M.p.,
B.p.
"C.
173 63 Liq. Liq. Liq. Liq. Liq. Liq. 225 206 d. 80 63 21 168 146 60 15 78 Liq. 82 136 Liq.
OC.
Dec. on distn. 142 158 155 175 158 180 Dec. on distn.
Dec. on distn. 145 170
-Vm.
Uranium, % Calcd. Found
0.0002 .OOl ,001 ,001 ,002 .OOOl
37.6 34.5 31.9 31.9 29.7 29.7 27.7
37.8 34.5 31.9 31.5 29.7 29.5 27.8
.0002 .0003
28.2 27.0 29.4 31.6 27.7
27.7 27.7 29.8 31.6 27.6
28.1 28.6 26.3 26.3 ,001 24.7 24.7 ,001 24.7 24.7 ,003 23.2 23.4 ,005 f 23.3 .002 23.4 88 h 23.4 23.4 ,0002 74 22.5 22.1 ,004 f 20.7 20.7 ,003 26.1 26.0 0002 90 51 i 24.6 24.5 ,0008 65 83 21.4 ,008 22.0 Liq. 65 6,O 22.3 ,001 22.4 70 60 29 For 2-Furyl. Previously prepared, see ref. 3. a Previously prepared by W. Biltz and J. A. Clinch, see ref. 2. general methods of preparation and literature references to these compounds see C. R . Hauser, F. W. Swamer and J. T. Adams, in Adams, "Organic Reactions," Vol. 8, John Wiley and Sons, Inc., New York, N. Y., 1954, pp. 59-196. e A. L. Henne, M. S.Newman, L. L. Quill and R. A. Staniforth, THISJOURNAL, 69, 1819 (1947). J J. C. Reid and M. Calvin, ibid., 72, 2948 (1954). See Experimental. F. Swartz, Bull. SOC. acad. roy. Belg., [5] 12, 679 (1926). See ref. 3. 1
88 74 88 86 91
116 132 134 142 141 145 166 191 114 123 162
'
through oxygen, nitrogen or sulfur atoms. Eventually a considerable knowledge of the chemistry of such organic compounds of uranium was evolved, and some relatively stable and volatile products were discovered. One of the most obvious approaches to finding volatile compounds appeared to be through preparation of chelate complexes with 1,3-dicarbonyl reagents. Indeed, the uranyl and uranium(1V) acetylacetonates already had been reported. We undertook the synthesis of a variety of uranium chelate compounds with 1,3-diketones and p-ketoesters, and this paper is an account of that phase of the work. At the time of our investigation, other laboratories were engaged with the same problem; consequently there was some duplication of effort. The group under Dr. H. I. Schlesinger3 a t the University of Chicago prepared a number of the same uranium compounds that we did. Many of the dicarbonyl intermediates, particularly those containing the trifluoromethyl group were synthesized for the first time during this work. Recently, some of these have been described by others. In Table I are recorded the uranium(1V) chelates together with their melting and boiling points. These compounds ranged in color from olive-green to dark brown. They were insoluble in water but ( 2 ) W Hiltz and J. A . Clinch, 2. CWZOYE. Chem., 40, 221 (1904). (3) H. I. Schlesinger, H. C. Brown, J . J. Katz. S. Archer a n d I
