34
EDWARD s. LEWIS.4ND
the collection of the samples of nitrogen gas for analysis were carried out in a high vacuum apparatus. The reaction vessel. was a 50-ml. round-bottomed flask connea.ted by a side arm t o another vessel of about 5-ml. capacity. T h e side arm and the smaller vessel were constructed in such a way t h a t , when this vessel was rotated 180' about the connecting ground glass joint, the contents of the vessel emptied into the reaction flask. Samples of nitrogen gas generated in the reaction flask were conducted through a liquid nitrogen-cooled trap into a collection vessel, of about 10-ml. capacity, by a Toepler pump. This collection vessel was constructed with a narrow, thin-walled neck to facilitate sealing. T h e samples of nitrogen collected in this way were analyzed mass spectrometrically. The vacuum line was evacuated by a n oil diffusion pump backed u p by a mechanical pump. Another mechanical pump was used for evacuating the reaction flask during the preliminary degassing of its contents, in order t h a t this degassing procedure should not contaminate the whole vacuum line. Final degassing was accomplished by opening the reaction flask t o the high vacuum line. Decomposition and Reaction of Benzenediazonium-a-N15 Fluoroborate with Azide.-Eighty per cent of the benzenediazonium-a-S'j fluoroborate was decomposed by heating a solution of it (0.2 g. in 10 ml. of deionized water) a t 35' for 130 min. (or a t 50' for 17 min.).6 The solution was then cooled to O 0 , and suficien t bromine was added t o convert the phenol produced during the decomposition into tribromophenol, which precipitated as a white solid. This was removed b y filtration and washed with 3 rnl. of ice-cold water. The filtrate and washings, containing the residual 0.04 g. of diazonium salt, and 10 ml. of ethanol were poured into the reaction flask of the high vacuum apparatus. A solution of sodium azide (0.04 g., a threefold excess) in 2 ml. of aqueous ethanol ( 5 volumes of water to 1 of ethanol) was poured into the side vessel, and both solutions were frozen in a freezing mixture of acetone-Dry Ice. T h e solutions were separately degassed by repeatedly freezing, pumping out, and thawing. T h e azide solution was added to the diazonium solution and the temperature was maintained a t ca. -27" for 7 5 min. T h e solution was frozen, and the "primary" nitrogen was removed using the mechanical pump (except in one experiment when it was collected for analysis to confirm t h a t it contained only natural abundance of P).The solution was degassed by thawing, freezing, and pumping out three times, keeping the temperature below 0 " . Finally, the solution was frozen, and the reaction flask was left open t o the vacuum line for 15 min. T h e reaction flask was isolated from the vacuum line and the solution was warmed to 0". The temperature of the solution was allowed to rise to room temperature while the "secondary" nitrogen was being evolved (about 2 lir.). The solution was again frozen, the nitrogen was conducted into the collection vessel by the method previouslr described, and the vessel was sealed. (8) E A Lloelwyn-Hughes and P J o h n s o n , T r a n s F a r a d a y Soc , 36, 948 (1940)
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Decomposition and Reaction of p-Toluenediazonium-o-Nl6 Fluoroborate with Azide.-A solution of the diazonium salt (0.165 g.1 in water (10 ml.) was heated a t 48.5' for 195 miti. t o bring about 80'3 d e c o m p ~ s i t i o n . ~The solution was cooled and extracted with ether to remove the p-cresol. Dissolved ether was removed by bubbling air, under reduced pressure, through the combined aqueous solution and washings ( 3 ml.) for 15 min. During the reaction with azide and the collection of the "secondary" nitrogen, there were no essential differences between the procedure used for this compound arid t h a t used for the benzenediazonium salt as described above. Reduction of the Aryl Azides with Arsenite.-The aryl azide solution remaining in the flask after the reaction of the aryldiazonium salt with sodium azide, and a solution of arsenite (0.34 g. of arsenic trioxide and 0.6 g. of potassium hydroxide in 2 ml. of 5: 1 aqueous ethanol) in the side vessel were degassed in the usual way. the final 15-min. degassing, the solutions were warmed t o rootn temperature and the arsenite solution was added to the aryl azide solution. When t h e evolution of nitrogen had ceased (after ca. 4 hr.), the solution was warmed to 50' to ensure completion of the reaction and was then frozen. The nitrogen was collected for analysis. An independent control showed t h a t sodium azide did not yield nitrogen with arsenite under these conditions. The above experiments were repeated without the initial 80"' decomposition, to show t h a t substantial isotopic rearrangement was occurring only during solvolysis of the diazonium salts. In a separate experiment, the nitrogen evolved during the solvolysis of benzenediazonium-a-95 fluoroborate was collected for analysis, using the techniques described above, in order to show t h a t S I 5 was present in the diazonium salt to the expected extent. Decomposition of Benzenediazonium Fluoroborate in Presence of Carbon Monoxide.--.I solution of 1 g. of benzenediazonium fluoroborate in 2,s ml. of water was allowed to decompose a t room temperature under 700 p.s.i. of carbon monoxide (in a steel bomb with a glass liner). After 19 hr. (>goyc, b u t < 9 5 5 decornposition),'~S~lo solid sodium bicarbonate was added to dissolve any benzoic acid, a n d the solution was extracted with ether t o remove the phenol. The aqueous layer was acidified arid again extracted with ether. On evaporation of this ethereal extract, no benzoic acid was detected.
Acknowledgment.-iVe thank the Robert -1.Welch Foundation for support of this work and for a postdoctoral fellowship to J . M . I. We also express our gratitude to l3r. E. G. Carlson and his co-workers a t the Shell Oil Co., who performed the mass spectrometric analyses, without which this work could not have been done. (9) E . S Lewis, J. I.. Kinsey, a n d R . K . Johnson, J A m ChPm. Soc., 78, 4294 (1936): J E. T a y l o r a n d T . J Feltis, zbid , 74, 1331 (1952) (10) K K . Brower, i b z d . , 8'2, 4535 (1960).
DEPARTMENT O F CHEMISTRY, RICE VXIVERSITY, HOVSTON, TEXAS]
Intermediates in the Hydrolysis of p-Toluenediazonium Ion' BY
EDU7ARD
s. LEWISA N D JOAN
31.
INSOLE
RECEIVEDJ U N E 24, 1963 Thiocyanate ion accelerates the decomposition of p-toluenediazonium ion in aqueous acid, but not linearly. The first increase in rate is almost saturated with 0.6 '11 S C S - , a second larger increase is linear up t o 3 'W SCK-. These rates and more qualitatively the products suggest two intermediates, X and Y ; X mostly reverts t o the diazonium ion and is apparently identical with the unselective intermediate previously identified as the aryl cation. I t may also be related to the intermediates in aliphatic deamination; Y is far more selective and its return t o diazonium ion is quantitativell- correlated with the isotopic rearrangetnent previously reported. It is isomeric with the diazonium ion and is believed t o have the spiroc)-clic structure I. The isotope effect for p-toluenediazonium-a-"5 ion, k14/kls = 1.019, is reported.
Introduction The increase in the rate of hydrolysis of benzenediazonium ion by added thiocyanate ion was taken as evidence t h a t an intermediate was formed reversibly.* The possibility that this intermediate had the carbonnitrogen bond already broken was suggested, b u t not denionstrated, by the observation t h a t both benzenediazonium and p-toluenediazonium ions showed a mixing of isotopic label on the two nitrogens in the diazoI ) T h e lto and c y , = k y , kuo. 'Thus C Y D represents the relative rate constant for the conversion of Y to D compared to its reaction with water. We can write the new equation ( 8 ) , derived by adding A and 'i
If we make the further assurilption t h a t C X D is far larger than c x ~ ( T )a t all values of (T), then the denominator of the first term in 8 is approximately (W) CXD and we shall define the new constant CD = ~ D X / [(W) C X D ] which then leads to eq. 9 by straightforward algebraic manipulation.
+
+
k,,,
=
+
(W)CD
kDY
+ CXTCD(T) (w) +
1 CYD
CYDkDy
~
CYT(T)
CvDkDv
(9)
which contains the five unknown constants CD, k D y , CXT, cyT, and C Y D , and is of the same form as the empirical eq. 1, which however contains only four constants. It is thus not possible t o evaluate the constants in eq. 9 without further information. Such information can be obtained from the yields sufficient to calculate the constants. This can be shown by dividing eq. 7 b y eq. 6 to give eq. 10 after making the substitutions to include the c constants; YT and Yo are the yields of tolyl thiocyanate iso-
+
thiocyanate and p-cresol, respectively. The integration assumes that (T) and (W) are not time dependent and t h a t no products are present a t the beginning of the reaction. This equation allows, together with the rate data, the evaluation of all the constants; the calculated yield curve of Fig. 1 uses the set 2.8(2.7-6.0):
0.0228 X lo-' l./mole sec. (0.01-0.025) CYD = 21 moles/l. (6-38); CYT = 470 (400-%0) set.-' (0.24--1.0) k ~ = y 0.349 X C ~ = T
CD =
T h e parenthetical numbers represent the extreme ranges of each of these constants using various rather less satisfactory fits to the data. I t is clear t h a t the agreement between the observed and the calculated p cresol yields using these constants is far less than perfect. A somewhat better agreement could be made by sacrificing some of the agreement to the rate constants, but this is not worthwhile. I n fact, the observed phenol yields are not exactly of the form calculated by eq. 10 even if all constants are quite arbitrary, using the assumption that (u') = 55.5 Ali'(this assumption was used in calculating the yield curve in Fig. 1). The error in this assumption is substantial a t high thiocyanate concentrations and is even worse if the several water molecules solvating the potassium ion are considered inert. X correction for this effect would reduce the calculated yields a t high thiocyanate concentration and improve the agreement. No correction was made because the error introduced is probably smaller than that of neglecting salt effects on the various rate constants. The salt effects cannot be reliably estimated, so only qualitative agreement between any model and the experiment can be expected and i t appears t h a t the fit is adequate under these circumstances. -4 further possible source of discrepancy is that a reaction of either X or
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Y which is first order in thiocyanate ion may give cresol. for instance if water solvating the anion is more reactive than ordinary water. I t will be seen that the intermediate Y is quite selective in that it reacts with thiocyanate far more rapidly (even within the large uncertainty) than with water ( C ~ = T k \ , ~ , ' k y o= 470), but X isveryunselective ( C S I . = 2.8). An independent indication may be obtained from the mode of attachment of the thiocyanate. At low concentrations most of the thiocyanate containing materials are derived from Y, but a t higher concentrations X contributes more extensively. Using the measured yields of tolyl isothiocyanate and tolyl thiocyanate yields calculated by difference (using interpolated values of cresol yields), the ratio US:YN has the values 34 a t (T) = 0.105 -91,4.4 a t (T) = Cl.66 M, and 4.5 a t (T) = 3.0 -If. n'hile the minimum is clearly unreasonable, the markedly higher value a t low ( T ) is clear and confirms the high selectivity of Y. The rate of return from the intermediate X to D cannot be calculated; it is assumed to be large compared to other fates of X. The rate of return from Y to D is readily calculated; i t is the amount t h a t the rate falls below the linear asymptote of Fig. 1 or, alternatively, the magnitude of the negative term in eq. 1. At zero thiocyanate concentration i t then has the value 10.85 = 0.09BG X 1 0 P set.-'. Graphically, this is the difference between the observed rate a t (SCN-)= 0 and that extrapolated from the linear portion of the curve of Fig. 1. From the previous work the rate of the isotopic turnaround reaction of N I5-labeled diazonium ion is 0.029 times the solvolysis rate = 0,043 X I O F 4 set.-'. We may then say t h a t the rate of return from Y is twice the rate of isotopic rearrangement, within the experimental error of each determination. The correction of the isotopic rearrangement rate for the isotope effect now measured and previously ignored is trivial. Support for this view may also be obtained on the unsubstituted cornpound. Using the rate data of ref. 2 on unsubstituted benzenediazonium ion, and making the reasonable assumption that all measured rates were on the essentially linear portion of a curve like t h a t in Fig. 1, these then yield (by least squares) the extrapolated value a t (SCN-) = 0 of 4.16 X sec.-'if all the data are used, or -1.25 X lO+ using only the presumably most reliable data (condition I, Table I1 in ref. 2). These exceed the observed rate by 0.08 and O . 1 i X 10Y set.-', respectively, and are there. fore estimates of the return from an intermediate like Y. The isotopic rearrangement rate3 is 1.4% of the solvolysis rate, or 0.037 X 1OF4set.-'. This value is, within the far larger experimental error, again about one-half of the extent of return from the intermediate. If Y returns half the time to an unrearranged diazonium ion, and half to the rearranged ion, Y most likely has two equivalent nitrogens, and these are not of the form of free molecular nitrogen. iVe propose the structure I for Y, in order to explain the rate and rearrangement data, and also the larger extent of rearrangement with the p-tolyl compound than the unsubstituted compound. C H 3-G l I
Some further consequences of this proposed structure for Y are being explored. The nature of the intermediate X is in many ways more puzzling for X must have the following characteristics in order to explain the new kinetics and the
HYDROLYSIS OF ~-TOLUENEDIAZONIUM IOK
Jan. 5. l W 4
older observations : (1) I t must return predominantly to the diazonium ion. ( 2 ) The two nitrogen atoms must maintain their identities (since all rearrangement is now attributed to Y). ( 3 ) I t is highly unselective. (4) Arguments on the effect of structure on rates, formerly applied to support the intermediacy of aryl cations, must now be explicable in terms of a mechanism through X. (5) Since most of the reaction a t SCN= 0 goes through X, the significant isotope effect suggests a weakened C-N bond. Of these, 1 and 3 are difficult to reconcile If an intermediate is unselective, it has probably almost no activation energy for its bimolecular reactions, and therefore to say t h a t the return reaction is far faster than these reactions of very low activation energy must be to say t h a t it must have a very large Arrhenius preexponential factor, compared to the reactions of X with solvent or nucleophiles. L e suggest that X may be an excited state of the diazonium ion, probably a vibrational state having nearly all the activation energy in it, which can react by a properly oriented collision a t the nitrogen-bearing carbon atom, but which will be deactivated by the large majority of collisions elsewhere on the molecule. The low selectivity follows naturally and the substituent effects can be reasonable if this excited state has a charge distribution similar to t h a t in the aryl cation. a'ith a highly bent diazonium salt such as 11, the contributions of IIc and to a lesser extent I I a must be
37
Reaction coordinate.
Fig. 2.-Energy-reaction coordinate plot for reaction through the perceptibly stable intermediate X (solid line), and for a onestep reaction of starting material ( D ) by way of a transition state closely resembling X, but containing the nucleophile.
tains a nucleophile and a nitrogen molecule on the same side of carbon, has possible application to the knotty problem of the aliphatic deamination reaction, in which i t has been necessary to propose a carbonium ion intermediate different from that in solvolytic reactions to explain the reaction course.7
Experimental IIa
IIb
IIC
markedly reduced because of the unfavorable bond angles. Only I I b is free from angle strain, so that. the process of bending the C-N bond might reasonably make the molecule more like a phenyl cation. The arguments apply equally well to a linearly stretched molecule. I t should be noted t h a t this argument for a two-step reaction via the intermediate X is entirely equivalent to a one-step bimolecular reaction, provided that the transition state has very little new bond character, and very little of the old C-X bond either. The original and still valid argument* for X was that it was unreasonable to propdse a nucleophilic attack on the diazonium salt which was not markedly accelerated by the p-nitro group. I t is clear that a transition state for a bimolecular nucleophilic attack in which the new bond is hardly present but the C-Ti bond is nearly totally broken would not be activated by the p-nitro group, so that this mechanism fits all requirements. Figure 2 illustrates the relation between the two mechanisms. The solid curve shows the route through X. The first transition state contains the elements of the diazonium ion only, the second also contains a nucleophilic reagent, such as water or thiocyanate ion. From Hammond's postulate,6 both transition states strongly resemble X. The dotted line shows the onestep reaction. The single transition state contains both the nucleophile and the diazonium ion. and it still closely resembles X in energy and structure, but X is now a hypothetical molecule rather than a real intermediate. Lye prefer to talk in terms of the intermediate X because the structural resemblance of the transition state and the weakly bonded X is clear. The mechanism proposed, through X in which no carbonium ion need ever be formed and in which the transition state for the product determining step con( A i G S H a m m o n d , J .4ni Chem Soc
,
77, 331 (lO,i5)
Materials.-p-Toluidine was diazotized conventionally in hydrochloric solution and the diazonium salt was precipitated as the fluoroborate with fluoroboric acid. It coul: be kept as a white crystalline solid for several weeks a t about 0 . p-Toluidine was also diazotized in glacial acetic acid, methanol, and sulfuric acid with isoamyl nitrite; addition of ether precipitated p toluenediazonium bisulfate, which was dissolved in acetic acid and acetone and reprecipitated with ether. The c~-N'~-labeled diazonium salt was that described previou.;ly. 3 b Rates.-The technique described previously4 was used. X solution of about 0.4 g. of p-toluenediazonium fluoroborate was prepared in 50 ml. of water, 0.02 M in hydrochloric acid, and containing the desired amount of potassium thiocyanate. The solution was placed in the reaction vessel, wrapped with aluminum foil to exclude light, and cooled to ice temperature. Prepurified nitrogen, saturated with water, was passed in to remove oxygen through a bottom capillary tube used later for withdrawal of sample. The closed reaction vessel was then placed in the thermostat ( a t 48.81 i 0.02", as read on an uncalibrated thermometer), and after 0.5 hr. a sample was forced through the bottom tube with slight nitrogen pressure. The first part of this sample, not all contained in the thermostat, was discarded, the later part was then cooled rapidly and a sample, of 20 A , was taken. Subsequent samples of 25, 50, 7 5 , and 200 X were taken a t times calculated on the basis of a guessed rate constant. The analysis and calculation of the rate constant was exactly as described b e f ~ r e . No ~ rate constants are reported using a correction of more than 57; of the guessed rate constant, and in each case the reactions followed a first-order course accurately. However, curvature was observed in the presence of thiocyanate ion if the ratio of thiocyanate to diazoiiiu:ii salt was too large; we attribute this to a reaction between the diazonium salt and some hydrolysis product of the thiocyanate. There was therefore an upper limit on the thiocyanate concentration, and even the result a t highest concentration in Fig. 1 may be slightly biased for this reason. Product Yields.-About 0.4 g. of p-toluenediazonium bisulfate was dissolved in 50 ml. of freshly standardized potassium tliiocyanate solution in a n opaque glass vessel. I t was cooled to O " , flushed with nitrogen, then placed in the thermostat. Allowing 5 min. for warming up, it was then left long enough for 80:; decomposition, calculated from eq. l . Only 80'; reaction was used to minimize error from thiocyanate hydrolysis. The cooled solution was then titrated with 0.1 N sodium hydroxide to a methyl (7) M a n y aspects of this problem are summarized by H. Zollinger, "Dia7o and Azo Chemistry." 1nterscieI:cr Publishers, Inc., S e w Torh. N Y , 1861
38
EMILJ. MORICONIAND FRANCIS A . SPANO
purple end point. A concurrent experiment, carried to completion but without thiocyanate, gave a n assay on the diazonium salt, and there was between 98.5 and 99.5pc of the calculated acid produced. The assay was applied in calculating the yield of acid (and hence of p-cresol). A minor source of error was the perceptible coupling of the diazonium salt with the indicator. A gas chromatographic analysis for the other products was used. A solution of 1.239 g. of p-toluenediazonium bisulfate was dissolved in 150 ml. of potassium thiocyanate solution and cooled, degassed, and decomposed as before. After essentially complete reaction, the mixture was extracted with ether, the ether solution reduced in volume, and a measured amount of methyl benzoate added a s an internal standard. A 1-rn. column of 55 Carbo-
[CONTRIBUTION S O .730 FROM
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Vol. 86
wax 1500 on Chromosorb P separated all the products and the yield of p-tolyl isothiocyanate was calculated from the area of its peak and t h a t of the internal standard. p-Tolyl thiocyanate and p-cresol were also detected in the chromatogram, but were not measured quantitatively. They were identified by comparison of retention times with those of authentic samples. Tolyl thiocarbamate was not eluted from the column in a reasonable time, and the efficiency of extractions of p-cresol was not high, so the areas of the tolyl thiocyanate and the p-cresol peaks were not used.
Acknowledgment.-We thank the Robert A . Welch Foundation for the support of this work.
DEPARTMEXT OF CHEMISTRY, FORDHAM UNIVERSITY, KEW YORK,N.
\'.I
Heteropolar Ozonization of Aza-Aromatics and Their N-Oxides1-3 BY EMILJ. MORICONI A N D FRANCIS A. SPANO RECEIVED J U N E 20, 1963 The ozonization of four aza-aromatics [1-methyl- (12) and 3-methylisoquinoline (17), acridine ( I ) , and phenanthridine ( 4 ) ] and five aza-aromatic N-oxides [quinoline-1- (24), phenanthridine-5- (29), acridine-10- (32), isoquinoline-2- (42), and 3-methylisoquinoline-2-oxides (45)] are reported. Initial electrophilic ozone attack on 1, 4 , 12, and 17 led to carbocyclic ring-cleaved carboxylic acids; simultaneous nucleophilic ozone attack a t the C-atom adjacent t o (4), or conjugated with ( I ) , the aza-atom produced cyclic amides. Relative t o isoquinoline, the methyl group in 12 and 17 deactivated the aza-aromatic ring to electrophilic ozone attack. Generally, initial nucleophilic ozone attack on aza-aromatic S-oxides led to cyclic hydroxamic acids and cleavage of the C = S aromatic bond ( t o nitroaldehydes) as primary products. IVith ozone as an electrophile, further ozonization of the former led t o deoxygenated products, cyclic amides. Phthalic acid was also obtained from 42 and 45. In almost all cases, solvent effects were noted. S+O and C=O absorption frequencies of reactants and products are tabulated
The low reactivity of the pyridine ring to ozone in the measurement of isoquinoline absorption characteristics ~ N - ~ x i d e , ~ and ~ of the ammonia formed on hydrolysis of the peroxidic parent compound and its h o m ~ l o g s ,of~ ,its and quinoline and its alkyl derivatives".' is well docuozonolysis products, LVibautfibhas reported that in this mented. Although alkyl substituents on the pyridine heterocyclic ring system, the aza-aromatic moiety nucleus effectively enhance its reaction rate with reacted one and one-half times more rapidly than the o z ~ n e ,the ~ ~rate , ~ is still considerably lower than for the benzenoid' nucleus. In all aza-aromatics ozonized, corresponding benzene derivative, and the yields of however, i t has been generally assumed t h a t only C=C ozonolysis products are little improved over the parent cleavage occurs in both carbocyclic and heterocyclic heterocycle. In quinoline and its derivatives, major nuclei'" and that the ammonia formed resulted from hydrolysis of the primary scission products, the acid attack seems to occur initially in the carbocyclic ring, amides. followed b y a slower attack a t the 3,4-bond of the heterocyclic ring. In this paper we report on the ozonization of the azaWhat is perhaps surprising is the unusual reactivity of aromatics : acridine, phenanthridine, 1-methyl- and 3isoquinoline to ozone. Ozonolysis of this aza-aromatic methylisoquinoline, their N-oxides, and quinoline-1with excess ozone in glacial acetic acid containing trace and isoquinoline-2-oxide. amounts of water produced 3,4pyridinedicarboxylic Acridine (1) and Phenanthridine (4) .-Ozone reacted acid, and, after hydrogen peroxide oxidation, phthalic readily with acridine (1) in both methanol and methylacid in almost equal a m o ~ n t s . From ~ a quantitative ene chloride solvents; with two molar ozone equivalents in methanol, followed b y alkaline hydrogen peroxide ( I ) P a p e r X I 1 in t h e series e n t i t l e d "Ozonolysis o f Polycyclic Aromatics", oxidation, 1 gave ring-cleaved 2,3-quinolinedicarboxylic for P a p e r X I : E. J . Moriconi a n d I,. B T a r a n k o , J OrR. C h e m . , 28, 2.526 (1963). acid (acridinic acid) (2) in 73-75yo yield and less than ( 2 ) T h i s research w a s s u p p o r t e d p r e d o m i n a n t l y b y G r a n t C A - 0 3 3 2 5 ~ 0 0 0. 1Yc of the oxygenated !+acridanone (3) ; in methylene f r o m t h e U S. P u b l i c H e a l t h S e r v i c e , Piational C a n c e r I n s t i t u t e . a n d in chloride, however, 60-620/, of 2 and up to 2.57, of 3 were p a r t b y t h e D i r e c t o r a t e of Chemical Sciences. Air Force Office of Scientific obtained. In both instances, 2-3yc of 1 was also reResearch, under G r a n t AF-AFOSR-62-18. ( 3 ) P r e s e n t e d in p a r t a t t h e M e t r o p o l i t a n Regional h l e e t i n g . American covered. Chemical S o c i e t y , New Y o r k , S Y , J a n , 1962; a t t h e 112nd S a t i o n a l Phenanthridine (4) did not react with ozone in methM e e t i n g of t h e American Chemical Society, Org I > i v . ,Atlantic C i t y , N J , anol, and only sluggishly in methylene chloride. In the S e p t , 1 9 6 2 ; a n d a t t h e X I X t h I U P A C C o n g r e s ? , I.ondon, J u l y 15, 1963. latter solvent, two molar equivalents ozone absorption (4) (a) F. 1, J S i x m a . Rer liaz) rhim , 11, 1124 (1852), (b! J . P W i b a u t a n d E . C K o o y m a n , ibid , 66, 1 4 1 (19-16), ( c ) E. C K o o y m a n a n d J . P followed by alkaline peroxide oxidation produced up W i h a u t , zbid.. 66, 705 (1917) (.5) ( a ) G S l o m p . J r , a n d J 1. J o h n s o n , J . A m . Chem o.'f , 8 0 , 913 (1958). (b) C. S l o m p . J r , J O i g . Chem , 2 2 , 1277 (19.57). (0) ( a ) J P. W i h a u t a n d H . Boer. Rec. lrnz'. c h i i n , 1 4 , 241 (195.5); ( b ) H. Boer, F I, J . S i x m a , a n d J . P . W i b a u t , ibid , I O , 309 ( 1 9 5 1 ) ; (c) J P W i b a u t a n d H B o e r , P ~ o r K o n i n k l . S e d A k a d . U e f e n s c h n p , 63, I 9 (1950). (7) W S h i v e . F: C.. Ballweher. a n d W . W A c k e r m n n . J A m Ckem S o r 68, 21 1 1 (191fi). ( 8 ) J P . W i h a u t . C h i m i n . 11, 298, 321 ( 1 9 5 7 ) , J . P . U'ibaut, J . r h i m . P h y s . , 111, 113 (1950) (9) A . F 1 , i n d e n i t r u t h a n d C . A. V a n d e r W e r f . J A m Chew S o r , 1 1 , 3020 (1919) Since ozone oxidizes acetic acid t o peracetic acid.8" t h e use of acetic acid a s a s o l v e n t i n ozonization reactions i n v a r i a b l y leaven t h e n a t u r e of t h e a c t u a l oxidant in d o u b t . I n t h i s i n s t a n c e , h o w e v e r , IVihaut a n d co~w,orkerTRh h a v e r e p o r t e d t h a t t h e a b s o r p t i o n c h a r a c t e r i s t i c o f isoquinoline i n glacial acetic acid a t Z O O is in principle n o different from t h a t in chlorn-
f o r m a t - 40'' T h e r e is n o d o u b t hnwever t h a t f u r t h e r o x i d a t i o n o f t h e peroxidic ozonolysis p r o d u c t s with hydrogen peroxide in acetic acid solvent m u s t be s t r o n g l y accelerated b y t h e equilibrium presence o f peracetic acid I t i s u n f o r t u n a t e t h a t n c p r o d u c t yields a r e reported in ref Oh ( I O ) T h i s conclusicm i q based on a q u a n t i t a t i v e m e a s u r e m e n t of ozone u p t a k e a n d a m m o n i a formed.4" R h a n d product i s o l a t i o n : 2.2.6-trim ethyl^ cyclohexanecarhoxamide f r o m 2 - f 2 , 2 , ~ - t r i m e t h y l c y c l o h e x y l ) - ~ , 0 ~ d i r n e t h y l p y r i d i n e . ) ) m e t h y l e t h y l a c e t a m i d e from 2-(s~r-butyI)-1.T,-dimethyIp~ridine,~~ a n d glyoxal, c a r h o n dioxide. a n d h y d r a z i n e from pyrazole ' 3 N o n i t r o u s or nitric acid w a q f o u n d o n ozonolysis of t h e p y r i d i n e nucleus 11 1 ) B. S h i v e . S.M R o b e r t s , R . I h l a h a n . a n d J K Bailey. J A m ( ' h e m .So< , 6 4 , BO9 (18.12). ( 1 2 ) H I. Imchte. W U' C r o u c h , a n d E . 11. T h o m a s . t h i d , 64, 2 7 5 3 [ 19-12! (13) B P Jibben and J P U'ibaut. Rer l r n v chim , 79, 312 (19fiO)
