beneath the surface of ethyl alcohol, the products are: amorphous carbon, graphite, acetaldehyde (1.5%), acetylenes condensed at -40° to -80° (0-3%), and a gaseous mixture of the composition: acetylene, 7-9.9%; ethylene, 6.0-9.6%; carbon monoxide, 20-24%; hydrogen, 46-50%; paraffins, 20-4 6.8%. Traces of diacetylene are also present (see following abstract). G. M. BENNETT.

Diacetylene [butadi-inene]. F. G. MÜLLER (Helv. Chim. Acta, 1925, 8, 826-832; cf. Baeyer, Ber., 1885, 18, 2272; A., 1925, i, 626).-The gases evolved in the electropyrogenetic decomposition of ethyl alcohol (preceding abstract) are cooled to -30° to -40° and from the liquid thus condensed the diacetylene is removed as silver salt and preserved under water (0.5-1 g. from 1000 c.c. of alcohol). The gas liberated from this salt by concentrated hydrochloric acid is fractionated first at the ordinary pressure and then in a vacuum with liquid air cooling. The pure butadi-inene has m. p. 36° to -37°, b. p. +13.6°. Earlier observations are confirmed as to its copper salt, silver salt, conversion by bromine into a hexabromide, m. p. 181°, and by iodine into a di-iododiacetylene, m. p. 93°, exploding at 95°. The liquid polymerises very rapidly at the ordinary temperature to an insoluble, amorphous, dark brown solid not melted at 350°, but exploding at a red heat.

G. M. BENNETT. Symmetrical substitution derivatives of trimethylene dibromide and pentamethylene dibromide. W. H. MILLS and L. BAINS (J.C.S., 1925, 127, 2502-2507).-Hydratropaldehyde reacts with formaldehyde and potassium carbonate to give B-phenyl-3-methylpropane-ay-diol, m. p. 88°, b. p. 184°/17 mm. Prolonged action of hydrogen bromide on the diacetate (b. p. 179°/20 mm.) yields ay-dibromoB-phenyl-3-methylpropane, b. p. 143-146°/12 mm. From the glycol, a-bromo-y-hydroxy-3-phenyl-3-methylpropane, b. p. 173°/15 mm., and a-chloro-y-hydroxy-ßphenyl-3-methylpropane, b. p. 117-118°/15 mm., were also prepared, and from the diacetate a-bromoy-acetoxy-B-phenyl-3-methylpropane, b. p. 174-174-5°/ 18 mm., was obtained. Hydrogen bromide reacts with ay-diacetoxy-3-phenylpropane to form ay-dibromoB-phenylpropane, b. p. 152°/14 mm., which, like the previous dibromide, has a strong geranium-like odour. Di-3-phenoxyethylacetic acid treated with hydrogen bromide yields ethyl as-dibromopentane-y-carboxylate, b. p. 166-167°/19 mm., which combines with piper. idine to form 4-carbethoxybis piperidinium-1: 1'-spiran

bromide,

[CH2 CHCH2 CH2 CH2 CH2 CH_CH>CH N CHCHCH-CO2Et Br (hygroscopic crystals, picrate, m. p. 130°). This passes on hydrolysis into 4-carboxybis piperidinium1: 1'-spiran bromide, m. p. 289-290° (decomp.); picrate, m. p. 169-170°.

B. W. ANDERSON.

Action of sodium on bromoethylenes. A. KIRRMANN (Compt. rend., 1925, 181, 671-673).Ground sodium reacts with solutions of bromoethylene derivatives to form hydrocarbons, without the liberation of hydrogen. With compounds of the type CHR:CHBr and CRBr:CH2, the substances CHR:CH2

and CR:CH are produced, the latter only in traces in the case of the second compound, together with small quantities of certain condensation products which are not formed by Wurtz' syntheses. Derivatives of the type CRRCHBr yield diolefinic hydrocarbons (cf. Pogorzelsky, A., 1899, i, 785). Delacre's interpretation of the reaction (cf. A., 1906, i, 476) is untenable, since, among other things, the presence of water is formed. The exact course of the reaction is unknown, unnecessary and intermediate hydrocarbons are not but a tentative explanation is offered.

S. K. TWEEDY.

Formation of nitrosates from olefines.

F. W.

KLINGSTEDT (Ber., 1925, 58, [B], 2363-2370; cf. Schaarschmidt and Hofmeier, A., 1925, i, 877).The formation of solid compounds by addition of nitrogen peroxide appears to be in general a property of such ethylenic compounds as contain the double linking between a secondary and tertiary or two tertiary carbon atoms. The yield of such compounds is invariably far below that expected on theoretical grounds. Attempts to base a method for the determination of ethylenic compounds on this reaction are unsuccessful, since the yield of solid bisnitrosate is dependent, not only on temperature, time, and composition of the reaction mixture, but also on the absolute quantity, so that reproducible results cannot be obtained. The yield of 3-methyl-AB-butene bisnitrosate from the hydrocarbon and nitrogen tetroxide in ether or light petroleum is about one-tenth that from the same weight of hydrocarbon, amyl nitrite, and nitric acid. The yield of B-methyl-Aspentene bisnitrosate from the hexene and nitrogen tetroxide in light petroleum appears to increase up to a certain point with increasing temperature (cf. Schaarschmidt and Hofmeier, loc. cit.). Maximal yields are obtained only when a certain time is given for the process of polymerisation and the temperature of the mixture is not allowed to exceed 0° greatly. Sooner or later secondary changes commence in the bluish-green liquid portions of the mixture, which may ultimately cause the complete disappearance of the solid bisnitrosate.

Further attempts to obtain a quantitative method for the determination of olefines are based on the assumption, as recorded in the literature, that the bluish-green liquid portions consist mainly of the unimolecular form of the nitrosate, which might possibly be combined with a suitable base and weighed as the solid nitrolamine. The solid bisnitrosates react readily with aniline, for example, giving the corresponding nitrolamine in a uniform yield of 70-80°, The liquid products, however, do not yield similar products and are therefore regarded as containing for the most part compounds which differ in constitution or configuration from the readily polymerised nitrosate. This supposition is in harmony with the observation that the process of polymerisation in the original mixtures occurs with comparative rapidity and that the bulk of the liquid products possesses no tendency to polymerise to the bisnitrosate. Similarly, the addition of nitrogen trioxide, nitrosyl chloride, or nitrosyl bromide to ethylenic compounds appears generally to give a mixture of products.

Dehydration of primary alcohols containing tertiary radicals. A. FAVORSKI and (MME.) J. ZALESSKI-KIBARDINE (Bull. Soc. chim., 1925, [iv], 37, 1227-1234). The dehydration of primary alcohols containing a tertiary carbon atom, and in which two of the groups attached to the latter are similar, when effected by treatment of the chlorohydrin with alcoholic potassium hydroxide or pyridine, yields olefines in which the two identical groups are symmetrical with respect to the double linking, one of these groups migrating: CR,R'CH, OH-CRR':CHR (cf. Haller and Bauer, A., 1913, i, 168; Favorski, J. Russ. Chem. Soc., 1918, 50, 63). Blondeau's deduction that in the dehydration reaction the relative migratory powers of the phenyl, methyl, ethyl, and benzyl groups decrease in the order given applies only to particular experimental conditions examined by him.

The chlorohydrin of methyl ethyl ketone, b. p. 85°/ 280 mm., 111°/761 mm., when heated successively with magnesium and gaseous formaldehyde yields hexane, hexylene, and B-methyl-B-ethylbutanol, b. p. 111°/145 mm., 155°/738 mm., d 0.8407, n 1-4253 (allophanate, m. p. 102°, phenylcarbamate), which on oxidation with chromic acid yields a mixture of an acid (silver salt, C,H130,Ag) and an aldehyde (semicarbazone, C.H17ON,, m. p. 174°). Hydrogen iodide at 0° converts the alcohol into the iodohydrin, which with alcoholic potassium hydroxide affords y-methylA-hexene, b. p. 93-8-94-2°/755 mm.

R. BRIGHTMAN.

Transformation of alkylvinylcarbinols into B-alkylallyl alcohols. R. DELABY (Compt. rend., 1925, 181, 722-724; cf. Baudrenghien, A., 1922, i, 710; Delaby, A., 1923, i, 753).-Ethylvinylcarbinol when treated with bromine yields aß-dibromo-npentan-y-ol, which with sodium formate gives the aß-diformate; this when heated and subsequently treated with potassium hydroxide yields As-pentena-ol, the yield of the last-named from ethylvinylcarbinol being 20%L. F. HEWITT.

Catalytic hydrogenation under reduced pressure. R. EsCOURROU (Chem. et Ind., 1925, 14, 519-529).-See B., 1925, 1011.

Substitution by halogen of the hydroxy-group of secondary alcohols. P. A. LEVENE and L. A. MIKESKA (J. Biol. Chem., 1925, 65, 507-513).The halogenation, whether by means of hydrogen iodide, thionyl chloride, or phosphorus pentachloride, of butan-ẞ-ol, 8-methylpentan-8-ol, and aß-diphenylethanol, resulted in all cases in a reversal of the optical rotation. d-8-Methylpentan-3-ol, prepared from the racemic compound by the method of Pickard and Kenyon (J.C.S., 1907, 91, 2058), had [x]+22-38° and gave, with hydrogen iodide, the iodide, [a] -18.08°; 1-8-methylpentan-B-ol, [a] -7-63°, with thionyl chloride in pyridine gave the chloride, [a] +20-41°; d-aß-diphenylethanol, [ +16-73°; with phosphorus pentachloride gave aß-diphenylethyl chloride, [a]-2-13°, whilst the l-isomeride

with thionyl chloride gave a chloro-derivative having [a] +7-36°. The chlorination of these compounds was attended with difficulties and was probably accompanied by some racemisation. C. R. HARINGTON.

Aliphatic nitro-alcohols. E. SCHMIDT, A. ASCHERL, and L. MAYER (Ber., 1925, 58, [B], 24302434; cf. A., 1923, i, 288). The conditions under which aliphatic nitro-alcohols can be reduced to the corresponding hydroxylamines without simultaneous formation of the amines have been determined. The success of the method appears to depend on the maintenance of a suitable hydrogen-ion concentration in the solution.

The preparation of a-nitropentan-3-ol, b. p. 8788°/3 mm., d 1.0847, n 1.4421, x-nitro-y-methylbutan-3-ol, b. p. 83-84°/4 mm., and a-nitro-8methylpentan-ß-ol, b. p. 90-91°/2 mm., 99-100°/ 6 mm., de 1.0519, n 1-4433, is described in detail. Reduction is effected with hydrogen in the presence of palladised barium sulphate. Nitromethane and a-nitropropan-ẞ-ol in aqueous solution in the presence of oxalic acid give hydroxylaminomethane oxalate (NHMe-OH)2,C,H2O4, m. p. 158° (decomp.), and a-hydroxylaminopropan-3-ol oxalate, m. p. 111° (decomp.). In 96% alcoholic solution, a-nitrobutanB-ol and a-nitropentan-3-ol similarly afford a-hydroxylaminobutan-3-ol oxalate, m. p. 100-101° (decomp.), and a-hydroxylaminopentan-B-ol oxalate, m. p. 99° (decomp.), whereas for the production of a-hydroxylamino-8-methylpentan-3-ol oxalate, decomp. 144-145°, the addition of acetic acid is necessary. a-Nitro-ymethylbutan-3-ol is hydrogenated in aqueous alcoholic solution in the presence of oxalic acid to a-hydroxylamino-y-methylbutan-B-ol oxalate, m. p. 106-108° (decomp.), whereas the production of a-hydroxylamino-octan-3-ol oxalate, decomp. 142-143°, requires the simultaneous presence of acetic acid.

H. WREN.

Catalytic preparation of ethyl ether from ethyl alcohol by means of aluminium oxide. R. H. CLARK, W. E. GRAHAM, and A. G. WINTER (J. Amer. Chem. Soc., 1925, 47, 2748-2754).-By passing ethyl alcohol vapour over aluminium oxide at 250°, an 80-8% conversion into ethyl ether and water was obtained (cf. Pease and Yung, A., 1925, ii, 37) and the reversibility of the reaction confirmed by demonstrating the formation of alcohol when ether and water are passed in equimolecular proportions over the catalyst at the same temperature. The catalysts were prepared (a) by precipitating aluminium hydroxide slowly from an 8% solution of sodium aluminate (Al2O3: Na,O=1 : 2) with 0-25N-sulphuric acid, washing the precipitate free from sulphate with cold water, washing again with hot water, and drying by heating gradually to 400°; (b) by precipitating a 10% solution of the same salt slowly with carbon dioxide and drying the washed precipitate at 350°; and (c) by allowing a similar 10% solution to deposit alumina by hydrolysis on keeping. Catalysts prepared by the last two methods gave yields of ether lower than 50% unless complete removal of alkali was effected by repeated heating to 400° and washing in hot water. Catalyst (c), when free from alkali, gave the highest

yields. No diminution in activity of the catalysts was observed after the conversion of 1500 c.c. of alcohol. A corrected table and chart are given for the determination of ether in mixtures of ether, alcohol, and water by the method of Pease and Yung (loc. cit.). F. G. WILLSON.

Preparation of aliphatic ethers. J. B. SENDERENS (Compt. rend., 1925, 181, 698-700; cf. A., 1923, i, 432; 1924, i, 638; 1925, i, 113).-Four more ethers have been obtained by heating the corresponding alcohol with the proportion (by volume) of sulphuric acid mentioned at the temperatures given: n-heptyl ether, b. p. 261.5°/745 mm., with 3% of concentrated sulphuric acid at 145°; cetyl ether, m. p. 55°, decomp. about 300°, with 4% of sulphuric acid trihydrate at 145°; sec.-amyl ether, b. p. 162° (corr.)/748 mm., d13 0-775, with 2.5% of concentrated sulphuric acid at 120°; allyl ether, with 20% of sulphuric acid trihydrate at 105°. With increase in mol. wt. less acid is required to accomplish etherification and secondary require less acid than primary alcohols. L. H. HEWITT.

I.

Organic phosphoric acid derivatives. Formation of primary phosphoric esters. ZETZSCHE and M. NACHMANN (Helv. Chim. Acta, 1925, 8, 943—945).—Monoalkyl phosphates have been obtained, in 9-17% yield, as barium salts by interaction of organic halides with an aqueousalcoholic solution of silver dihydrogen phosphate in presence of an excess of phosphoric acid to prevent the formation of the di-silver salt. The following are described barium benzyl phosphate, CH,Ph.O·PO ̧Вa; barium allyl phosphate, +H2O; barium 3-bromoethyl phosphate, +EtOH+H2O; barium y-iodo-3-hydroxypropyl phosphate, +EtOH, from di-iodo-n-propyl alcohol, and barium y-bromo-n-propyl phosphate, +EtOH, from trimethylene dibromide.

G. M. BENNETT.

Oxidation of secondary mercaptans. P. A. LEVENE and L. A. MIKESKA (J. Biol. Chem., 1925, 65, 515-518).-1-3-Iodoisohexane was converted (with some racemisation) into the corresponding mercaptan, the least racemised preparation of which had [+21-21°; on oxidation with nitric acid. this yielded l-isohexane-3-sulphonic acid, [a] -6.68; aß-diphenylethyl mercaptan, [a] +8.56°, gave, on oxidation, aß-diphenylethylsulphonic acid, [x-36-40°. This reversal of rotation on oxidation is similar to that observed in the case of other mercaptans (A., 1924, i, 940) and resembles that accompanying the halogenation of secondary alcohols (cf. this vol., 45). The latter fact suggests that the stereochemical relationships between the mercaptans and the sulphonic acids are similar to those between the alcohols and their halogen derivatives.

C. R. HARINGTON.

Occurrence of free radicals in chemical reactions. IV. Decomposition by iodine of silver salts of organic acids. H. WIELAND and F. FISCHER (Annalen, 1925, 446, 49-76).-By the interaction of iodine with the silver salts of organic acids, the complex substances described by Simonini

(A., 1893, i, 391) can be isolated. The formula Age OOCR I is preferred to that suggested by OOCR Simonini. The decomposition of these complexes by water and by heat has been studied for the following acids acetic, hexoic, phenylacetic, triphenylacetic, cholic, crotonic, cinnamic, phenylpropiolic, benzoic, glycollic, lactic, mandelic, benzilic, oxalic, succinic, tartaric, glutaric, adipic, phthalic, hexahydrophthalic, maleic, and fumaric, and for ethyl hydrogen succinate. With water they all react thus: 3(R-CO2),AgI+ 3H20 6R.CO2H+2AgI+AgIO,, the complex taking up hydrogen with the formation of silver hypoiodite, which passes into the iodide-iodate mixture. The thermal decomposition of the complex in the fatty acid series leads to the formation of esters : (R-CO2)2AgI→R.CO2R+CO2+AgI (cf. Heiduschka and Ripper, A., 1923, i, 894) and the same occurs to a less extent in the aromatic series (except phthalic acid, cf. Birnbaum and Reinherz, A., 1882, 970). The complexes from many acids evolve only a small amount of carbon dioxide and the acid is largely regenerated, hydrogen being withdrawn from a part of the substance thus: 2(RH-CO2),AgI → 2RH CO2H+(R·CO2)2AgI+AgI. Far more than half the original acid is regenerated, showing that a complex which has once lost hydrogen tends to lose more. Birnbaum and Gaier, A., 1880, 801), that from The complex from succinic acid yields maleic acid (cf. glutaric acid yields y-butyrolactone (cf. Windaus and Klänhardt, A., 1921, i, 392) and that from ethyl hydrogen succinate yields ethyl B-carbethoxyethyl succinate, b. p. 166–171°/12 mm. In no case could a hydrocarbon be isolated during the decomposition of the complex and hence, contrary to the statement of Birnbaum and Gaier (loc. cit.), the mechanism cannot be similar to those of the Kolbe electrolysis or the decomposition of diacyl peroxides (cf. Fichter and Fritsch, A., 1923, i, 438). It is concluded that the free radical R.CO2 does not take part in any of the reactions, but that the complex as a whole is always R. W. WEST.

involved.

Do free alkyl radicals occur in the Kolbe electrochemical synthesis of hydrocarbons ? H. ERLENMEYER (Helv. Chim. Acta, 1925, 8, 792797).-The production of methyl bromide or iodide, when the Kolbe electrolysis of potassium acetate is carried out in presence of sodium bromide or iodine, which has been cited as evidence for the transitory existence of free radicals, has now been shown to occur only to the extent of a 0.5% current yield, whereas the figure for by-products normally present is 2-3%. Moreover, the usual yield of ethane is still obtained in these experiments. The formation of methyl halide is accounted for on the assumption that peracetic acid occurs at the anode, and reacts as follows: Me CO2H+HX=MeX+CO2+H2O, this reaction having been found to occur with synthetic peracetic acid. G. M. BENNETT.

Action of phenylhydrazine and hydrazine on fats and fatty acids. J. VAN ALPHEN (Rec, trav. chim., 1925, 44, 1064-1070).-The observations of Falciola (A., 1920, i, 476) as to the action of hydrazine

of

on fats have been repeated, using an absolute methylalcoholic solution of hydrazine, and the direct form ation of the hydrazides of the fatty acids has been confirmed. Not only oleic acid, but also the unsaturated acids of linseed oil are reduced in the process, yielding stearylhydrazide. The substitution phenylhydrazine for hydrazine leads to the production of phenylhydrazides of each acid without any reduction of the unsaturated acids. The fatty acids are isolated from the hydrazides by heating with dilute sulphuric acid and benzaldehyde. Palmitylphenylhydrazide, m. p. 110-5°, is prepared by heating the acid or its esters with phenylhydrazine at 130— 150°; its m. p. is not depressed by admixture of stearylphenylhydrazide. Ricinoleylphenylhydrazide, m. p. 63°, is obtained in a similar manner from castor oil. Stearylhydrazide reacts with aldehydes to yield stearylhydrazones; benzylidenestearylhydrazone, C17H35 CO NH-N:CHPh, m. p. 83°, and o-nitrobenzylidenestearylhydrazone, m. p. 97.5°, are described.

G. M. BENNETT.

Action of halogens on acraldehyde in dilute aqueous solution. Trihalogenated propionic acids. A. BERLANDE (Bull. Soc. chim., 1925, [iv], 37, 1385-1394).-a-Monosubstituted acraldehydes are readily obtained by the action of halogens on acraldehyde in dilute aqueous solution. It is It is improbable that hypochlorous or hypoiodous acid plays any part in the reaction, since under the conditions described these acids yield only traces of the a-halogenated acraldehyde. Thus acraldehyde with 1 mol. of 2-67% bromine water gives an 80% yield of a-bromoacraldehyde, n 1·501, d 1.67 when freshly distilled, increasing to 1.90 after 15 days at 25°. Bromine in ethereal solution converts it into aaß-tribromopropaldehyde, oxidised by fuming nitric acid (cf. Moureu and Chaux, A., 1924, i, 1281) to aaß-tribromopropionic acid, m. p. 94° (yield 70%). The ethyl ester has d23 2-084, no 1·532, b. p. 140-142°/30 mm. Similarly, chlorine in carbon tetrachloride gives (yield 75%) aß-dichloro-a-bromopropaldehyde, b. p. 81°/45mm., das 1-83, n 1.511, oxidised to aß-dichloro-a-bromopropionic acid, m. p. 61-62° (ethyl ester, b. p. 132133°/45 mm., d 1-161, n 1-482). -Chloroacraldehyde, obtained in 50% yield, similarly yields aaß-trichloropropaldehyde, b. p. 63°/42-45 mm., d25 1·470, n 1-473, oxidised to aaß-trichloropropionic acid, m. p. 50-52° (ethyl ester, b. p. 121°/55 mm., d 1.36, n25 1-458), and a-chloro-aß-dibromopropaldehyde, b. p. 105°/55 mm., d20 2.17, n 1-548. a-Chloro-aß-dibromopropionic acid, m. p. 73°, its calcium salt (+2H2O, lost at 110°), and ethyl ester, b. p. 142-143°/45 mm., d 1.84, n 1.504, are described. a-Iodoacraldehyde, b. p. 37°/8-9 mm., d 1.82, is obtained in 25% yield by the action of iodine in aqueous potassium iodide. The product rapidly becomes very viscous, probably through polymerisation, as the analytical figures remain unchanged.

25

R. BRIGHTMAN.

isoOleic acid and other unsaturated fatty acids formed by distillation of -hydroxystearic acid. V. VESELY and H. MAJTL (Chem. Listy, 1925, 19, 345–356).-Pure -hydroxystearic acid yields on distillation a solid consisting of a eutectic mixture of

A'-elaïdic and Ao-elaïdic (isooleic) acids, and a liquid containing ordinary oleic acid and its A'-isomeride. B. W. ANDERSON.

30

23

730

Structure of chaulmoogric and hydnocarpic acids. R. L. SHRINER and R. ADAMS (J. Amer. Chem. Soc., 1925, 47, 2727-2739).-Chaulmoogric acid is reduced rapidly by hydrogen in alcoholic solution in presence of platinum oxide to dihydrochaulmoogric acid, m. p. 71-72° (cf. Barrowcliff and Power, J.C.S., 1907, 91, 557), hydnocarpic acid yielding similarly dihydrohydnocarpic acid, m. p. 64-65 (cf. Dean and Wrenshall, A., 1921, i, 91; U.S. Pub. Health Bull., 1924, 141, 25). Methyl chaulmoograte and methyl hydnocarpate are reduced analogously, with formation of methyl dihydrochaulmoograte, m. p. 27°, b. p. 204-205°/10 mm., da 0.9018, n 1-4356, and methyl dihydrohydnocarpate, b. p. 187-188°/10 mm., d 0.9057, n 1.4523. Bromodihydrochaulmoogric Bromodihydrochaulmoogric acid (cf. Power and Gornall, J.C.S., 1904, 85, 838, 851), m. p. 37-38°, is converted by the action of alcoholic potassium hydroxide into a mixture containing 22% of chaulmoogric acid. Ethyl bromodihydrochaulmoograte, [α] +7.1°, obtained by the action of hydrogen bromide on ethyl chaulmoograte in light petroleum, yields similarly a mixture containing 5.4% of chaulmoogric acid. Oxidation of this mixture with dilute aqueous potassium permanganate at 18-20°, followed by esterification of the product with methyl alcohol, affords a methyl ester, m. p. 64—65°, b. p. 220-250°/9 mm., which, on hydrolysis, yields the corresponding acid, m. p. 125-126°, previously designated by Barrowcliff and Power (loc. cit.) as y-keto-p-methyl-n-pentadecane-az-dicarboxylic acid. On reduction with amalgamated zinc and hydrochloric acid, however, this ketonic acid affords n-hexadecane-aa'-dicarboxylic acid, m. p. 118°, which was synthesised by the electrolysis of potassium ethyl sebacate, and is therefore 8-keto-n-hexadecaneax'-dicarboxylic acid, its derivation from chaulmoogric acid being formulated as follows: CH=CH.

CH, CH,>CH·[CH2]12*CO2Et
CH,CHBr

CH-CH

HBr

CH2-CH2 >CH•[CH2]12*CO2Et

CH,CH, C[CH]CO,H

KMnO

KOH →

CO,H[CH,]*CO [CH,]z*CO,H.

On treatment with ozone in glacial acetic acid solution, followed by decomposition of the ozonide according to the method of Helferich and Schäfer (A., 1925, i, 7), chaulmoogric acid yields a vitreous solid, which, when treated with dry ammonia in ether, yields ammonium ay-dialdehydo-n-pentadecane-xcarboxylate, and, when oxidised with chromic acid in glacial acetic acid, followed by esterification with methyl alcohol, affords trimethyl n-pentadecaneaa'y-tricarboxylate, m. p. 37-38°, identical with that obtained by esterification of the acid produced by direct oxidation of chaulmoogric acid with potassium permanganate (cf. Power, loc. cit.). Methyl chaulmoograte yields, similarly, a liquid, non-purifi

able product, from which, on treatment with hydr. oxylamine, the dioxime of methyl ay-dialdehydon-pentadecane-a'-carboxylate, m. p. 93-94°, was obtained. An isomeric dioxime, m. p. 102–103°, was produced under different conditions. Consideration of the above reactions, and a review of other transformations of chaulmoogric acid, lead to the conclusion that the cyclopentene form of Power's suggested tautomeric structure gives adequate representation of the structure of chaulmoogric acid, and that it is not actually a tautomeric substance.

F. G. WILLSON.

Action of ethyl acetopyruvate on diazonium hydroxides. FAVREL and C. H. R. Z. JEAN (Bull. Soc. chim., 1925, [iv], 37, 1238-1241). The sodium derivative of ethyl acetopyruvate reacts readily with diazonium compounds either in acetic acid or in the presence of a large excess of hydrochloric acid, yielding crystalline substances which are soluble in alkali and are provisionally regarded as hydrazones of the type CO,Et-CO-C(COMe):N-NHAr. Benzenediazonium chloride in acetic acid gives 96% of the theoretical yield of the y-phenylhydrazone of ethyl acetopyruvate, m. p. 111-112°; in hydrochloric acid the yield is 78%. The y-o-tolylhydrazone, lemon-yellow needles, m. p. 67-68°; y-p-tolylhydrazone, green, m. p. 113 114; y-o-nitrophenylhydrazone, yellow, m. p. 144145°; y-m-nitrophenylhydrazone, m. p. 106-107°; y-p-nitrophenylhydrazone, m. p. 137-138°; y-mchlorophenylhydrazone, yellow, m. p. 91-92°, and the y-m-bromophenylhydrazone, m. p. 99-101°, are similarly obtained in yields varying from 73% to 99% of theory. R. BRIGHTMAN.

Oxidation of oxalic acid with potassium permanganate. G. SCHEFF (Biochem. Z., 1925, 160, 390-397).-When potassium permanganate in excess reacts with oxalic acid in the presence of sulphuric acid at 70°, the reduction is greater than that calculated from the equation 2KMnO4+3H2SO4 +5C2H2O4-K2SO4+2MnSO4+10CO2+8H20.

If

the reaction time is constant, the permanganate reduced is proportional to the oxalic acid present. The secondary reaction, which is not completed in 30 min., is thought to be 2KMnO4+3MnSO4+2H2O =K2SO4+2H2SO1+5MnO2. E. C. SMITH.

Configuration of ax'-dibromodibasic acids. IV. ax'-Dibromoglutaric acids. H. R. ING and W. H. PERKIN, jun. (J.C.S., 1925, 127, 2387-2399; cf. ibid., 1921, 119, 1393; A., 1924, i, 1039, 1162).— Dibromination of glutaric acid yields a mixture of meso-aa'-dibromoglutaric acid, m. p. 170°, and the dl-acid, m. p. 142°. The methyl and ethyl esters. have been prepared by Ingold's method (ibid., 1921, 119, 316). Ethyl ax-dibromoglutarate, b. p. 162°/ 14 mm., is an inseparable mixture of the two isomerides. Methyl meso-aa-dibromoglutarate, m. p. 45°, was obtained by boiling the meso-acid in methyl alcohol containing 10% of sulphuric acid, while the dl-ester, obtained similarly from the dl-acid, forms an oil, b. p. 143–145°/10 mm. By heating the dibromoesters in methyl alcohol with sodium iodide, a solid methyl aa'-di-iodoglutarate, m. p. 75°, and a liquid ester were obtained.

In the case of sodiomalonic ester, the compound II further condenses to the sodium derivative of ethyl ketodicyclopentanetricarboxylate (III). The cyclobutane ester predominates (yield 70-80% in one case) when the condensation is carried out in absence of alcohol, e.g., in benzene. Ethyl bromocyclopropanedicarboxylate on hydrolysis yields 1-bromocyclopropane-1: 2-dicarboxylic acid, m. p. 175° (aniline salt, m. p. 132°). Ethyl cyclobutane-1: 2: 2: 3-tetracarboxylate is an oil, b. p. 195-198°/12 mm. Methyl cyclobutanetetracarboxylate exists in a solid, m. p. 78°, and a liquid, b. p. 193-195°/15 mm., form. Pure meso- and dl isomerides of methyl dibromoglutarate, separately condensed in benzene solution with methyl malonate, gave in each case a mixture of the solid and liquid forms of the cyclobutane ester, so that these condensations yield no evidence as to the configurations of the dibromoglutaric esters. A similar result was obtained in condensations with methyl cyanoacetate. Descriptions are given of ethyl-2-cyanocyclobutane-1: 2: 3-tricarboxylate, b. p. 210-2150/20 mm.; methyl 2-cyanocyclobutane1: 2: 3-tricarboxylate, solid form, m. p. 111—112°; liquid form, b. p. 185-190°/12 mm.; ethyl 2-benzoylcyclobutane-1: 2: 3-tricarboxylate, and ethyl 2-acetylcyclobutane-1: 2: 3-tricarboxylate, b. p. 195°/18 mm. Hydrolysis of cyclobutanetetracarboxylic esters yields a mixture of cis- and trans-cyclobutane-1: 2: 3-tricarboxylic acids (Goldsworthy and Perkin, J.C.S., 1914, 105, 2665). The trans-form has been partly resolved into two optical enantiomorphs by crystallisation of the quinine salt. A. DAVIDSON.

Addition of cyanoacetic esters to esters of glutaconic and B-methylglutaconic acids. E. P. KOHLER and G. H. REID (J. Amer. Chem. Soc., 1925, 47, 2803-2811).—Using carefully purified materials, methyl cyanoacetate condenses with dimethyl glutaconate in methyl alcohol in presence of just sufficient sodium methoxide to ensure alkalinity, with formation of the normal additive product (yield about 82%), which is converted, by the action of hydrochloric acid, into methanetriacetic acid (cf. Dreifuss and Ingold, J.C.S., 1923, 123, 2967), of which the dianilic acid has m. p. 206° (cf. Ingold, ibid., 1921, 119, 352). The yield of condensation product is greatly reduced when Thorpe and Wood's procedure is followed (ibid., 1913, 103, 1597), or if the reactants are not carefully freed from water and acid. Under similar conditions, no reaction was observed between ethyl cyanoacetate and the ethyl esters of either of the isomeric B-methylglutaconic acids. Operating under the conditions of Thorpe and Wood (loc. cit.), a pale yellow liquid, b. p.