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KISSINGER, MCQUISTION, SCHWARTZ, AND GOODMAN
sulfuric acid. The solution was heated on a steam bath for 15-30 min. In all cases, the cis-diols reacted visibly more rapidly than the trans-diols. A few drops of water were sufficient to precipitate the rearrangement product if this had not occurred a t the end of 30 min. The product was filtered, washed with water, and recrystallized. In this manner, the following four rearrangement products were obtained: g,i0-Dihydro-9-phenanthrcrne1m.p. 147-149" (lit. m.p., 152O)G from ethanol, was obtained from both cis- and trans-9,10-dihydro-9,10-phenanthrendiol. It is unstable on standing in air or in solution and changes color from pale yellow to pink t o red in a relatively short time. After rapid filtration, a single pale yellow crystal was quickly selected for melting point determination. The time interval between commencement of the rearrangement process and the melting point determination approximated 20 min. 10J O-Di(p-tolyl)-9,iO-dihydro-9-phenunthrone (IIIa), m.p. 163-164.5' from absolute ethanol was obtained in 90% yield from cis-IIa and in 80% yield from trans-IIa. A n d Calcd. for CZ~HZZO: C, 89.80; H, 5.92. Found: C, 89.69; H, 5.88. 13achmann4 DreDared IIIa. m.D. 158-159" bv a similar pinacol rearrangement using iodine and glacial acetic acid. iO,i0-Di(i-naphthyl)9,iO-dihydr~9~henunthrone(IIIe), m.p. 286-287O36 from absolute ethanol was obtained in 90% yield from cis-IIe and in 35% yield from trans-IIe. A
I
,
I
(35) F. R. Japp and A. Findlay, (1897). (36) See Table I, Ref. (e).
[CONTRIBUTION FROM
J. Chem. SOC., 1121
THE LOS
Anal. Calcd. for C&fzzO:C, 91.46; H, 4.97. Found: C, 91.45; H, 5.33. The infrared spectra of phenanthrones IIIa and IIIe are quite similar and show identical absorption bands, attributed to aromatic ketones at 5.92, 6.27, and 7.90 microns, and to aromatic substituents a t 6.90, 7.18, 12.62, 13.03, 13.26, 13.66, and 14.40 microns." Reuwangement Product (IIIb), m.p. 104-105" from ethanol was obtained in 95% yield from ck-IIb and in 90% yield from tram-IIb. Anal. Calcd. for CeoHMOa: C, 87.55; H, 6.61; Mol. wt., 823. Found: C, 87.56; H, 6.71; Mol. wt., 881 i 10% (Signer-Barger). The infrared spectrum of IIIb showed a weak band at 2 . 9 5 ~(OH), moderate bands a t 6.23p, 6.92p, 8.13, 9.25, and 1 0 . 5 7 ~(aryl substituents), and strong bands a t 6 . 0 1 ~and 13.65~; ,A 253 mp, hnsr 68,200.
Acknowledgment. The authors take pleasure in thanking the Research Corp. for grants initiating and supporting this work. Special thanks are due to William J. Schmitt, S. J., Woodstock College, Woodstock, Md. whose serendipity led us to this investigation. NEWYORK58, N. Y. (37) We are indebted to Mr. Daniel McCarthy for the infrared spectra (KBr) disk for these compounds.
ALAMOSSCIENTIFIC LABORATORY, UNIVEBsITY
OF
CALIFORNIA]
gem-Dinitro Esters. I. Preparation and Some Reactions of a-Hydroxy-P,fldinitropropionic and -butyric Acids L. W. KISSINGER, W. E. McQUISTION, M. SCHWARTZ,
AND
LEON GOODMA"
Received April 1, 1067 The preparation of a-hydroxy-B,fl-dinitro-propionicand -butyric acids by the condensation of dinitromethane and 1,ldinitroethane, respectively, with glyoxylic acid, their esterification and acylation, and some of their physical properties are described.
a-hydroxy-p-nitropropionic acid by the condensation of nitromethane with glyoxylic acid in aqueous solution. I n the present investigation a-hydroxy-p,p-dinitrobutyric acid (I)was prepared by the acid-catalyzed condensation of 1,l-dinitroethane with glyoxylic acid hydrate. It was also obtained, although in lower yield, in the attempted preparation of 2,2,5,5-tetranitro-3,4-hexanediolby the reaction of 1,l-dinitroethane with a commercial grade of glyoxal.BThe a-hydroxy acid was stable in acidic or neutral media but it rapidly reacted with two moles of base to form glyoxylate and dinitroethane anions. Esterification with ethanol or methanol in (1) Present address: Stanford Research Institute, Menlo the presence of sulfuric acid was normal in contrast Park, Calif.
As part of a study of the chemistry and properties of gem-dinitro esters, .several a-hydroxy-p,pdinitro acids and esters were prepared by the condensation of 1,l-dinitroparaffis with glyoxylic acid derivatives. The condensation of nitroparafis with carbonyl compounds to form nitro alcohols was first reported by Henry2in 1895. Subsequent studies of this reaction, primarily using mononitroparafhs, were reviewed by Hass and Riley.3 Chattaway and Witherington4 successfully used the hydrate of a carbonyl compound in this same condensation to obtain nitro alcohols. Shechter and Conrad6 prepared
(2) L. Henry, Compt.rend., 120, 1265 (1895). (6) a-Hydroxy-p,p-dinitrobutyricacid could arise in one (3) H. €3. Hass and E. F. Riley, Chem. Revs., 32, 406 of several ways, for instance, by oxidation of an inter(1943). 14) F. D. Chattawav and P. Witherington, . J. Chem. SOC., mediate condensation product as a-hydroxy-p,&dinitrobutyraldehyde or by preliminary oxidation of the glyoxal 1178 (1935). (5) H. Shechter and F. Conrad, J. Am. Chem. SOC.,75, to glyoxylic acid, followed by normal condensation. The mechanism of this reaction, however, waa not investigated. 5612 (1953).
DECEMBER
1957
1659
GEM-DINITRO ESTERS. I
similar manner from the a-hydroxy ester XI. While the a-hydroxy esters could not be obtained by direct esterification, potassium ethyl a-hydroxy-p,p-dinitropropionate (XIa) was obtained by the condensation of ethyl glyoxylate hemiacetal and potassium dinitromethane. Upon acidification the free hydroxy ester X I was formed. This difference in behavior of the butyric and propionic acids suggests the possible intermediate formation of the p,p-dinitroacrylate system in the latter case; however, efforts to prepare this intermediate were unsuccessful. Extensive decomposition, with elimination of oxides of nitrogen, was observed when the hydroxy ester X I was treated with dehydrating agents. The alkoxy esters were distilled unchanged from phosphorus pentoxide. Pyrolysis of ethyl a-acetoxy-p,p-dinitropropionate (XIII) resulted in the elimination of acetic acid and oxides of nitrogen, the residue being a mixture of organic compounds from which a pure component could not be isolated. Treatment of the acetoxy esters with base or urea again led to a mixture of products resulting from elimination of acetic and nitrous acids. Indeed it was observed in a qualitative way that nitrous acid was eliminated more readily from these compounds than was acetic acid. Ethyl a-acetoxy-p,p-dinitropropionate (XIII) was prepared directly by acetylation of the corresponding hydroxy ester X I and alternatively by H+ AcCl the potassium iodide dehaI~genation'-~of ethyl aFHOCHCOOH + CHaC(N02)2CHCOOH + I I I acetoxy-p-chloro-p,p-dinitropropionate (XV) ; the OH latter was obtained by acetylation of ethyl a-hyI OH I CHaC(N0z)zCHCOOH droxy-p-chloro-p,p-dinitropropionate(XIV) which I in turn arose by chlorination of ethyl a-hydroxyHZ804 OOCCHI @,p-dinitropropionatepotassium salt (XIa). RoH IV H+ 9 AcCl The potassium dinitromethane used in this work LROYHCOOR + CH&(N02)2YHCOOR + was prepared from 2,2-dinitropropanedio1-ll3by I reaction with aqueous potassium hydroxide and OH 6H R = Et I1 R = Et treatment of the resulting potassium salt of 2,2I11 R = Me dinitroethanol with hot alkaline peroxide solution. CHaC(N02)zCHCOOR It is of interest to note that use of strong aqueous alkali alone failed to convert the diol beyond the I OOCCHI dinitroethanol stage.
to that of the propionic analog, giving the corresponding ethyl and methyl esters I1 and 111; the former ester was also prepared by the condensation of 1,l-dinitroethane with ethyl glyoxylate hemiacetal. The nitro acid, however, was recovered unchanged after warming with concentrated sulfuric or polyphosphoric acid showing no evidence of lactide or polyester formation. Attempted preparation of the a-bromo acid by reaction with phosphorus tribromide gave instead, a phosphate ester which was free of bromine. Acetylation of the nitro acid and esters gave a-acetoxy-p,p-dinitrobutyric acid (IV) and the corresponding ethyl and methyl a-acetoxy esters V and VI. a-Trifluoroacetoxy-p,p-dinitrobutyric acid (VIII) was readily prepared by the action of trifluoroacetic anhydride on the acid but it was comparatively unstable. Ethyl a-hydroxy-p,p-dinitrobutyrate (11) was also rapidly cleaved to the anion of 1,l-dinitroethane by hydrazine hydrate or even dry ammonia. The a-acetoxy derivatives were more stable toward bases than were the free hydroxyl compounds. aAcetoxy-p,p-dinitrobutyric acid (IV) reacted as a monobasic acid although excess alkali slowly produced the 1,l-dinitroethane anion. Hydrazine hydrate and dry ammonia each cleaved the a-acetoxy esters from which low yields of 1,l-dinitroethane hydrazinium or ammonium salts were isolated.
I
I
V R=Et VI R = Me
I1
HaNNHa*HzO ___)
HzNNHi"[02N=C(N02)CHa]
VI1
-
EXPERIMENTAL'^ cu-Hydroxy-~,8-dinitrobufyTic acid (I). A. From glyoxylic acid. A suspension of 20 g. (0.17 mole) of 1,l-dinitroethane in 50 ml. of water containing 2 drops of concentrated sulfuric acid and 0.15 mole of glyoxylic acid" was heated on a steam bath with stirring for 6 hr. On cooling to room temperature the solution remained homogeneous. The crude acid was isolated from the reaction mixture by five ether extractions. After drying, the ether and excess 1,l-dinitroethane were
a-Hydroxy-p,p-dinitropropionic acid (IX) was obtained as a dipotassium salt (IXa) by the condensation of potassium glyoxylate hydrate with potassium dinitromethane in water. Acidification gave %hefree acid IX. In contrast to the behavior of the butyric acid, we were unable to prepare esters of this nitro acid (7) J. Meisenheimer, Ber., 36, 438 (1903). by direct esterification; instead, the a-alkoxy esters (8) E. P. Kohler, J. A.m. Chent. SOC.,38, 887 (1916). (9) K, Klager, Anal. Chem., 23, 534 (1951). were obtained. Thus, methyl a-methoxy-p,p-dini(10) Microanalyses by M. J. Naranjo and C. A. Esquibel. tropropionate (X) resulted from the reaction of temperatures are uncorrected. methanol on a-hydroxy-p,@-dinitropropionic acid All(11) The sirupy aqueous solution of glyoxylic acid, pre(IX) in the presence of sulfuric acid. Echyl a-eth- pared by the method of 0. Doebner, Qnn., 311, 129 (1900), oxy-@,p-dinitropropionate(XII) was pieparsd in a was assayed by titration with standard base prior to use.
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KISSINGER, MCQUISTION, SCHWARTZ, AND GOODMAN
-K
+
HOCHCOO-
I
VOL.
22
H+
+ 2K"[OzN=C(NO2)CHCOO] -- + CH(N0z)zCHCOOH
OH
AH IXa
IX
CH(N02)2CHCOOMe
