May, 19.51
COMMUNICATIONS TO THE EDITOR
2401
111 ( X = Br) IV ( X = H )
nin acetate (11), m.p. 228-230' de^.),^ [ a I z 6 ~duration of the experiment are shown below; no -24.6' (chloroform), Xg5%max. 240 m~ (log E solvents were used. The dehydrogenation of the 4.06), 311 mp (log e 2.08). Calcd. for C29Hd106Br: benzyl alcohol is accompanied by the reduction of C, 63.38; H, 7.52; Br, 14.54. Found: C, 63.79; the free radical corresponding to the substances H, 7.92; Br, 14.38. On cold, alkaline hydrolysis mentioned in Table I. Thus, from (I) the lactone 11,23-dibromohecogenin acetate formed ll-hy- of o-hydroxydiphenylacetic acid (111) was obtained, tetraphenylhydrazine yielded diphenylamine a n d droxy-23-bromohecogenin (111), m.p. 234.0-234.2' ~ D (dioxane). Calcd. for CZT- diphenyl disulfide yielded thiophenol. (dec.), [ L ~ ] ~-23.7' Hd106Br: C, 61.70; H, 7.87; Br, 15.21. Found: Ph 1 C, 61.77; H, 7.65; Br, 14.83. Reduction of the latter with zinc in acetic acid yielded ll-hydroxyhecogenin (IV), m.p. 216-2185', [ a ] " ~-37.1' (dioxane). Calcd. for C27H4205: C, 72.61; H, 9.48. Found: C, 72.36; H, 9.68. Treatment I I1 I11 with acetic anhydride in pyridine gave a diacetate, ~ (dioxane). Calcd. m.p. 230-231', [ a ] 2 e-70.7' TABLEI for CalH~07: C, 70.16; H, 8.74. Found: C, Temp. OC Hours 69.95; H, 8.63. The structures of I11 and IV follow tentatively 2,2'-Diket0-3,3-diphenyl-3,3'-dicoumnmnyl' (1) 110 2 from the identity of the hydrolysis conditions with 2,2'-Diphenyl-thioindigo white2 (11) 130 2 those which yielded lla- and ll~-hydroxy-l2-keto140 2 cholanic acids from the corresponding l l p - and Tetraphenylsuccinodinitrile*s6 110 1 lla-bromo derivatives.2 Treatment of IV with Tetraphenylhydrazine' 100 5 hot alcoholic alkali, as with pyridine or chroma- Diphenyl disulfide6 tographic alumina, gave rise to a mixture of isoMe' found also that phenyliodo dichloride (C&,meric substances having the composition of hy- ICh) converts benzyl alcohol into benzaldehyde droxyhecogenin and giving variously fractions when the two substances are heated a t 110' for 20 ~ to -37'. melting in the range 210-220°, [ a ]-27 minutes, whereas xanthhydrol was readily converted This indicates a rearrangement with the possible into xanthone. It is believed that these two reacformation of some of the expected ll-keto-12-h~- tions also proceed via a free radical mechanism, tlroxy isomer. I n view of the pyridine-acetic an- involving chlorine atoms. The yields of benzaldehydride conditions for formation of the diacetate as hyde (estimated through the 2,4-dinitrophenylwell as the failure of the latter to form an oxime, hydrazone) were good, in some cases exceeding the structure of this compound is not assigned. 70%. Further investigation of the keto1 rearrangement is (1) LLiwenbein and Simonis, Bet.., 67, 2040 (1924). in progress. (2) Kalb and Bneyer, ibid., 46, 3870 (1913). (3) Lowenbein, i b i d . , 68, 606 (1925); Wiltig, ibid., 66, 7 G O (!%E). We wish to thank the Research Corporation for (4) Wieland, A n n o k n , 881, 200 (1911). making this investigation possible. ( 5 ) Schonberg and Mustafa, J . Chcm. Soc., 889 (1949); Scllijn-
r
DEPARTMENT OF CHEMISTRY GEORGE P. MUELLER berg, Rupp and Gumlich, Be7., 66, 1932 (1933). E. STOBAUCH (6) This experiment was carried out with M. F. S. El-Hawary. ROBERT UNIVERSITY OF TENNESSEE KNOXVIILE,TENNESSEE ROBERT S. WINNIFORD DEPARTMENT OF CHEMISTRY 31, 1951 RECEIVED JANUARY FACULTY OF SCIENCE ALEXANDER SCHONBBRG FOUADI UNIVERSITY AHMEDMUSTAPA ABBASSIA-CAIRO, EGYPT DEHYDROGENATION REACTIONS BY THE ACTION RECEIVED DECEMBER 1, 1950 OF FREE RADICALS
Sir : Very little seems to be known about the strong dehydrogenating power of long-lived free radicals. We have found that the compounds listed in Table I, which all dissociate into free radicals of long life, a t least a t high temperatures (see footnotes l d ) , dehydrogenate benzyl alcohol to benzaldehyde. Experimental details concerning temperature and
ABSOLUTE MOLAL ENTROPIES OF TRANSFER OF IONS
Sir: I n a recent paper' Goodrich, Goyan and others have calculated absolute molal entropies of trans(1) J I, Goodrich, F M Goyan, E E Morsr K v U l l ~I l y I U U R N A ~ ,7a, 4-111 (1950)
hi 8
(:
Prr5too ann
2402
VOl. 73
COMMUNICATIONS TO THE EDITOR
fer for a number of ions from their data on nonisothermal cells with silver-silver bromide, and mercury-mercuric oxide electrodes. Their values (Table VI, ref. 1) are dependent upon an assumption concerning the entropy of transfer for large tetraalkylammonium ions, and differ considerably from earlier Difficulties arise, however, if these values are applied to the calculation of Soret coefficients. It is well-established theoretically3that the Soret coefficient (i for a uni-univalent electrolyte is given by ignoring corrections for
activities. Using Goodrich's values for KBr and KOH, respectively, we obtain a t T = 298' A.: UKBr = 3.9 x 10-3; UKOH = - 8.8 x 10-8. However, experimental measurements of %ret coefficients show that aqueous solutions of all electrolytes give negative values of Q. The calculated value for KOH is of the right sign and order of magnitude (cf. Tanner4),but this is not the case for the KBr value. It is, of course, true that Soret coefficients are difficult to measure, but it seems unlikely that such a difference in sign between bromides and hydroxides would not have been observed if Goodrich's assignment had been correct. It is clear that the experimental work on Soret coefficients requires that the net entropy of transfer for a salt must be positive, unless present theoretical views on these non-isothermal phenomena are to be changed. There is a further, minor, point. We are quoted (Ref. 1, p. 4417) as supporting a value of f 3.6 e.u. for the entropy of transfer of the bromide ion. It is clear from our paper5 that this value was calculated on Eastman's assumptions in order to test his equation on experimental results from mixed solutions of bromides, and that we attached no other significance to it.
27.35. Found: C, 53.58; H, 3.67; N, 4.71; Br, 27.70).
I
I
COCH,
COCH,
COOGHj
CK
CH- CHI
CHr-CH?
I
I
+
/
\
\
COCH, VI
COCHI VI1
a-Carboxysuccinic acid has been allowed to react with methylamine and formaldehyde in aqueous solution to yield the amino acid 111, m.p. 166168O (Anal. Calcd. for C&~INO*: C, 44.71; H, 6.88; N, 8.69. Found: C, 44.81; H, 6.91; N, 8.82) which has been converted with hydrogen chloride in absolute ethanol to the hydrochloride of the amino ester IV, m.p. 70-71' ( A n d . Calcd. for CloHzoNOiCl; C, 47.33; H, 7.95; N , 5.52; C1, 13.97. Found: C, 47.08; H, 7.90; N, 5.86; Cl, 13.94; p-toluenesulfonamide, m.p. 51-52O, Anal. Calcd. for C1~H26NO&: C, 54.97; H, 6.78; N, 3.77. Found: C, 54.61; H, 6.69; N, 4.02; pyrrolidone, V, b.p. 167-168°/20.5,Anal. Calcd. for COOH
COOH
(2) E . D. Eastmart, T H I S JOURNAL, 60, 292 (1928). (3) S. R . de Groot, J . Phys. R a d . , [SI 8,193 (1947) from the principle of microscopic reversibility; K. Wirtz, Z. P h y s i k , 114, 482 (19481, from a kinetic theory of liquids; L. D Tuck, J . Chcm. P h y s . , 18, 1128 (19501,from a thermodynamic method; H, J. V, Tyrrell, unpublished calculations, from the theory of rate processes. (41 Tanner, Trans. Far. Soc., 13,75 (1927). ( 5 ) H. J. V. Tyrrell and G. L.Hollis, i h i d . , 46, 411 (1449).
I
CH-COOH 4
CH&H, HCHO
CH?
I
CH-CHi-NH-CHZ
I
CHz
I
I
COOH
COOH 111
DEPARTMENT OF CHEMISTRY
H. J. V. TYRRELL G. I,. Hol,r,rs SHEFFIELD IO, EXGLAND RECEIVED FEBRUARY 9, 1951 SHEFFIELD UNIVERSITY
I
AMINO DERIVATIVES OF S-KETO-l,3,4,5-TETRAHYDROBENZ lcdlMDOLE*
COOC9Hs
CHr-CH-COOC?Hs
I
I
O=C,x//CH* I
-
I
CH-CHZ-SH-CHI CHz I
I Sir: CH? COOCiHi I n continuation of studies2 directed toward the v IT total synthesis of the ergoline ring system and of C8HlaNOa: C, 56.12; H, 7.65. Found: C, 56.10; lysergic acid, N-acetyl-5-keto-1,3,4,5-tetrahydroH, 7 . 5 5 , d2'20 1.1170, nZ5D 1.4620, calcd.: benz[cd]indole, I, m.p. 148-149' (Anal. Calcd. for C13HllN02: C, 73.22; H, 5.20; N, 6.57; N-acetyl, 12.43; MD found: 42.13). Condensation of XI with I V has afforded the 20.18. Found: C, 72.95; H, 5.24; N, 6.37; Nacetyl, 20.44) has been converted t o the 4-bromo- amino ketone VI, isolated as the picrate, m.p. derivative, 11, m.p. 162-163' (Anal. Calcd. for 158-160' ( A d . Calcd. for CleHaIN6Ola;C, 52.97; C13H10NO2Br: C, 53.44; H, 3.45; N, 4.79; Br, H, 4.75; N, 10.65; N-acetyl, 6.55. Found: C, 53.56; H,4.71; N, 10.85; N-acetyl, 7.14). I1 with ( 1 ) This investigation was supported rn part b ? .I research grant from /3-methylaminopropionitrile has yielded VII, m.p. The United States Public Health Service 128-129' ( A d . Calcd. for G,HnNa02: C, (1) t. C Uhlr, T H IJOURNAL, ~ 71, 781 (11149).
