252
NOTES
VOL.
24
( b ) Alcoholysis. Twenty to thirty ml. of the alcohol were treated with 0.1 g. of sodium. When reaction was completed, one gram of methyl 2-phenothiazinecarboxylate was added, and the mixture was refluxed 4-5 hr. The mixture was poured into water, filtered, dried, and recrystallized from ethanol-acetone mixtures.
adding an alcoholic solution of the carbonyl compound to a saturated solution of the reagent in 2M hydrochloric acid.? It has now been found that 2,4-dinitrophenylhydrazine is quite soluble in the dimethyl ether of Acknowledgment. We wish to thank the National diethylene glycol, for which solvent the name Cancer Institute, grant CY-2450-3 and the Up- diglyme has been coined.8 Solutions of the reagent john Drug Co. for financial assistance, the Upjohn made by warming 1 g. in 25 to 30 ml. of the solvent Drug Co. (Dr. R. F. Heinzelmann) for analyses, are stable a t room temperature. The neutral soluDr. C , C. Stock (Sloan Kettering Institute) tion is deep red in color. ilcidification with hydroand Dr. R. H. Levin (The Upjohn Drug Co.) chloric acid turns the color to yellow. It is not necessary to acidify the reagent solution for storage, for physiological testing. however. Solutions of the reagent in diglyme have DEPARTMENT OF CHEMISTRY been found to be admirable for the preparation of FISKUNIVERSITY derivatives, using, as is customary, hydrochloric 8, TENN. NASHVILLE acid for catalysis. Moderate success was also achieved in the use of acetic acid instead of hydrochloric acid for catalysis. A New Technique in Preparing 2,4-Dinitro- The reason for using acetic acid was two-fold. phenylhydrazones. Use of Diglyme as Solvent The use of a weak acid for catalysis in solutions at room temperature or lower may be applicable to the preparation of derivatives of sensitive comH. J. SHINE pounds, Also, in the preparation of derivatives of Received August 22, 1968 carbonyl compounds formed in the oxidation of glycols by lead tetraacetate the precipitatioll of An encumberance long associated with the char- the derivative may be complicated by the precipiacterization of carbonyl compounds by their 2,4- tation of lead chloride, unless the trouble iq taken dinitrophenylhydrazones is the difficulty of ob- first to separate the carbonyl compounds from lead taining concentrated solutions of 2,4-dinitrophenyl- acetate. If acetic acid can be used for catalysis of hydrazine. The low solubility of the reagent in use- 2,4-dinitrophenylhydrazolle formation it may be ful solvents is usually overcome by working with possible to use crude oxidation mixtures in the boiling solvents or with highly acidic solutions, preparation of derivatives. Results m-ith lead since the salts of the reagent are more soluble than tetraacetate oxidation solutions n-ill be published the reagent itself. Thus, 2,4-dinitrophenylhy- elsewhere. As can be seen in Table I success was drazones are usually prepared by resorting to one achieved in the four cases tried. However, the of several techniques now in practice. These are, formation of the derivatives was slo~v.In the case for example, adding to the carbonyl compound a of benzaldehyde the derivative crystallized nicely solution of the reagent in concentrated sulfuric acid, from solution 30 min. after adding the acetic acid. water, and ethanol': adding a solution of the reagent In the cases of methyl p-tolyl ketone and '?-ethylin ethanol containing hydrochloric acid2; adding l-tetralone the derivatives crystallized out overa solution af the reagent in 85% phosphoric acid night. I n each case, however. the amount of derivaand ethanol3; boiling the carbonyl compound in tive obtained was much smaller than expected from a methanol solution of the reagent acidified with the amount of compound used. The use of soluhydrochloric acid4;boiling the carbonyl compound, tions of 2,4-dinitrophenylhydrazine in acetic acid reagent, and hydrochloric acid in ethanol5; uniting alone or in aqueous acetic acid is to be avoided the carbonyl compound, reagent apd hydrochloric since acetylation of the reagent occurs when acid in a mixture of ethanol and dioxane6; and warming to dissolve. KO acetylation occurred in a control diglyme experiment. As might be expected, triglymes and tetrahydro(1) R. L. Shriner, R. C. Fuson and D. Y. Curtin, 2'he Systematic Identification of Organic Compounds, 4th ed., furan can be used as solvents for 2,4-dinitrophenylJohn Wile!: &. Sons, Inc., Neiv York, N. Y., 1956, p. 219. hydrazine. Undoubtedly, other solvents may be (2) W. J. Hickinbottom, Reactions of Organic Compounds, found. Because tetrahydrofuran needs t o be dis2nd ed., Longmans, Green and Co., Ltd., Xew York, N. Y., tilled prior to use and because of its volatility, we 1948, p. 161. (3) G. D. Johnson, J . Am. Chem. Soe., 73, 5888 (1951). found diglyme to be preferred. It was found un(4) X. D.Cheronis and J. B. Entrikin, Semimicro Quali- necessary to disttillthe diglyme before use.
tatiue Organic Bnalysis, 2nd ed., Interscience Publishers, N e w York, X. Y . . 1957, D. 393. (5) R. Adams and J . k . Johnson, Laboratory Experiments in Organic Chemistry, 4th ed., Macmillan Co., Xew York, N. Y. 1953, p. 257. (6) I. N. Nazarov, L. A. Kazitsvna, and I. T. Zarekskava, ,I. Gen. Chew., USSR, 27, (89), 606 (1957).
( 7 ) S. Veibel, The Identification of Organic Compounds, 1st English ed. (based on the 4th Danish ed.), G. E. C. Gad, publisher, Copenhagen, Denmark, 1953, p. 101. (8) H. C. Brown, E. T. Mead, and R. C. Subha Rno, J . Am. Chem. Soc., 77, G209 (1955).
FEBRUSRY
1%(3
253
NOTES
EXPERIMESTAL
Oxidation of Methyl 8-Nitrodehydroabietate.
The following procedure was used, in general, in preparing the derivatives given in Table I.
I1 WILLIAMJ. CONSIDINE~ A N D H. H. ZEISS Received August 36, 1968
TABLE I I I E L T I S G I'OISTS'
AXD
LITERATURE VALUES
Compound
RIP
Lit., "C.
methyl n-hexyl ketoneb methyl isobutyl ketoneb methyl isopropyl ketoneb acetoneb acetoneb*e cyclohexanone' acetaldehydeb formaldehydeb benzaldehyded benzaldehydee*e bmzaldehycled,f benzaldehydedJ acetophenoned cinnamaldehyded methyl p-tolyl ketoned methvl p-tolyl ketonecqe 7-ethyltetralone-ld 7-ethyltetralone-lcve p-hydroxybenzaldehyded
58-59 92-93h 123-124 125-126 124-126 160-161 165166% 165-166 238-240 239-240 239-2-10 239-240 247-248 255-256 257-259j 247-254 271-272 273-274 284-284.5
58' 95k 11P, 119-1 20" 126' 126' 161' 168' 166k 237' 237k 23Tk 237k 250' 255' 260k 260k 275" 275" 280'
We wish to report the results of a study of the oxidation of methyl 8-nitrodehydroabietate I with chromium trioxide a t 60". The oxidation of I with this trioxide at 70" has been shown to involve the destruction of the hydrophenanthrene system, and the products of the oxidation have been formulated as the ketol lactone IT1 and the enol lactone 11 arising from 111 by dehydration.1 I t has now been found possible to isolate compounds 1T'a and V from oxidations a t 60" as intermediates in the formation of the ketol lactone 111. The neutral fraction of the oxidation mixture in the present work consists of methyl 9-0xo-8iiitrodehydroabietate IT'a and is characterized by way of its 2,4-dinitrophenylhydrazone and ethylene ketal derivatives. The ultraviolet spectrum of IVa
Dilution with water needed to precipia Uncorrected. tate derivative. Derivative crystallized out dowly. Derivative precipitated immediately on adding acid. e Ten drops of acetic acid used instead of hydrochloric acid. Triglyme solution of reagent. Tetrahydrofuran solution of reagent. Recrystallized from ethanol: m.p. before tws 86-89'. Recrystallized from ethanol; m.p. before was 153-154'. See ref. 4, p. 586. Recrystallized from diglpme: m.p. before was 249-256". Ref. l . ,,,Ref. 4. This was prepared in these laboratories bv n conventional technique and recrystallized from ethyl acetate. Calcd. for Cl8HI8X~04: C, 61.01; H, 5.12; N, 15.80. FoundQ:C, 61.21; H, 5.19; N, 15.51.
'
FIGURE I
60"
IV
V I
%
A solution of 4 g. of 2,4-dinitrophenylhydrazinewas prepared by warming in 120 ml. of diglyme and allowed t o stand a t room temperature for several days. Five ml. of this solution, a t room temperature, was added to approximately 0.1 g. of the carbonyl compound dissolved in 1 ml. of 95% ethanol. Where the carbonyl compound was insoluble in 95% ethanol it was dissolved in diglyme, as, for example, in the case of p-hydroxybenzaldehyde. Three drops of concentrate hydrochloric acid were then added, causing the immediate formation of the derivative. In some cases the derivative precipitated immediately, in others dilution with water was necessary, while in one the derivative crystallized out slowly. The derivative cvas filtered, washed with ethanol or aqueous ethanol and dried by suction. I n only three cases was it necessary t o recrystallize the derivative to obtain a satisfactory melting point. Thus, the new technique gave excellent crudes in most cases, within a few minutes work. DEPARTMENT OF CHEMISTRY AND CHEMICAL ENGIKEER~KG TEXAS TECHNOLOGICAL COLLEGE TEX. LUBBOCK, (9) Schwarzkopf I,aboratories, Woodsidr 77, N. Y.
is consistent with this formulation, since the conjugation of the carbonyl function a t C-9 with the phenyl ring causes a shift in the positions of the absorption maxima of methyl 8-nitrodehydroabietate I as well as a large increase in the intensity of absorption (see Table I). Formation of the ethylene ketal IT'b blocks this conjugation and its spectrum is very similar to that of I, although :i small bathochromic shift is noticed in this case owing to the presence of the po1:ir ketal group. The infrared spectrum (Table I) of the ketone IT'a also shows the presence of the conjugated ketonic system by an absorption bend :Lt 5.91p. (1) Paper I: H. 1%.Zeiss snd >I. Tsutsui, ,I. aim. ('hem. Soc., 77, 6707 (1955). (2) Felton Chemical Co., Inc., 599 Johnson Avr., Rrooklyn 37, N. Y.
