methyl r-phenylsuccinate, which melted at 57-58.5°; this value remained unchanged after admixture with the synthetic ester. Action of Alkali on 1-Phenylsuccinic Acid. The 1-phenylsuccinic acid used in these experiments had [a]-148.3° in ethyl-alcoholic solution, a value which agrees well with the data of Wren and Williams (loc. cit.). Three comparative experiments were performed, in which the acid (1 gram) was treated in a closed vessel with (a) sodium ethoxide solution (1.059; 50 c.c.) and absolute ethyl alcohol (20 c.c.); (b) sodium ethoxide solution (50 c.c.), alcohol (20 c.c.), and water (0.95 c.c.), and (c) sodium ethoxide solution (50 c.c.), alcohol (10 c.c.), and water (10 c.c.). In each case a certain amount of precipitate separated. The mixtures were heated with frequent agitation during five hours at 70°, then neutralised with hydrochloric acid, and evaporated to remove alcohol; the acids were isolated by extraction of the acidified solutions with ether. The dried acids were polarimetrically examined in ethyl-alcoholic solution, the values for the specific rotations being (a) -146.6° (1=2, a c=2·8815, α。 −8·45°), (b) -145·5° (l=2, c=1·691, ap −4·92°), and (c) - 146·2° (l=2, c=1·7035, aь −4·98°). In no case, therefore, was any evidence of racemisation obtained. Complete Hydrolysis of Methyl d-Phenylsuccinate by Alcoholic Sodium Hydroxide containing differing Proportions of Water. In these experiments, the weight of ester and alkali, the total volume of the solution, the temperature, and duration were maintained uniform, the only variation consisting in the replacement of differing volumes of alcohol by water. Stock solutions of ester were prepared by dissolving 2 grams of the latter in 30 c.c. of ethyl alcohol, and of alkali by dissolving sodium in absolute ethyl alcohol; the latter solution was 11N. Ten c.c. of the ester solution were mixed with (a) alkali solution (25 c.c.), alcohol (25 c.c.), and water (0.45 c.c.); (b) alkali solution (25 c.c.), alcohol (15 c.c.), water (10 c.c.), and (c) alkali solution (25 c.c.), water (25 c.c.). The solutions were heated in closed flasks during four hours at 60-65°; precipitates speedily separated in (a) and (b) but (c) remained homogeneous throughout. The resulting mixtures were nearly neutralised with hydrochloric acid and evaporated to remove alcohol; the aqueous solutions were extracted with ether after acidification with mineral acid. The residual phenylsuccinic acids were polarimetrically examined in ethyl-alcoholic solution, when the following values were observed for the specific rotation: (a) +3·1° (l=2, c=2.2391, ap +0.14°); (b) +59 10 (1=2, c=1913, ap +2·26°); (c) +100 3° (l=2, c=20731, ap +4·16°). Complete Hydrolysis of Methyl d-Phenylsuccinate by AqueousAlcoholic Tetramethylammonium Hydroxide Solution. The solution of the alkali was prepared by warming an aqueous solution of tetramethylammonium iodide with a slight excess of silver oxide, and removal of silver iodide and unchanged oxide. The filtrate was concentrated to 14 c.c., and then diluted with ethyl alcohol to 55 c.c. An approximately N-solution was thus obtained. The methyl d-ester (1 gram) was heated during two and a-half hours with the solution described above, and the corresponding acid isolated in the usual manner; it melted at 164-168.5°, and had [a] +10.10 in ethyl-alcoholic solution (l=2, c=3.329, аD +0·67°). Action of Ferric Chloride on Methyl d-Phenylsuccinate. It has been shown by Meyer (Ber., 1911, 44, 2725) in the case of ethyl acetoacetate that ferric chloride exerts a direct enolising action. The behaviour of an ethyl-alcoholic solution of methyl d-phenylsuccinate towards anhydrous ferric chloride has therefore been polarimetrically investigated in the expectation that enolisation, if induced at the asymmetric carbon atom, would betray itself by racemisation. The solutions, however, were found to be optically stable under these conditions. Methyl d-phenylsuccinate (0-4869 gram) was dissolved in ethyl alcohol and the solution made up to 20 c.c.; a portion of this solution had a +6·73° when examined in a 2-dcm. tube, and this value had not changed at the end of forty hours after the addition of a small quantity of ferric chloride. A further portion of the latter substance was added, and the solution allowed to remain at the temperature of the laboratory during nine days, at the end of which period the ester was isolated and examined in ethyl-alcoholic solution; it had [a] + 129.8°, whereas the value +138-2° had been determined for the original specimen. Possible Enolisation of Methyl Phenylsuccinate in Solution. Methyl d-phenylsuccinate (0.5369 gram) and methyl r-phenylsuccinate (0-4496 gram) were separately dissolved in methyl alcohol (20 c.c.) and titrated with an N/10-solution of bromine in the same solvent until a faint, permanent, yellow coloration was produced; 0.55 c.c. of bromine was required in each case, whilst in a blank experiment 0.60 c.c. was necessary. Methyl d-phenylsuccinate (0.3292 gram) was dissolved in a wellcooled methyl-alcoholic solution of sodium methoxide, and the product poured into an excess of a solution of bromine in methyl alcohol containing hydrogen chloride. Excess of bromine was removed by the addition of B-naphthol dissolved in methyl alcohol, and the resulting solution warmed after addition of aqueous potassium iodide (10 per cent.). The liberated iodine required 0.3 c.c. of N/10-sodium thiosulphate solution, this quantity being the same as that required in a blank experiment. The author desires to express his thanks to the Research Fund Committee of the Chemical Society for a grant which has defrayed a part of the cost of the investigation. MUNICIPAL TECHNICAL INSTITUTE, BELFAST. [Received, February 20th, 1918 ] XXV.-Synthesis of 3:4-Dihydroxyphenanthrene (Morphol) and of 3:4-Phenanthraquinone. By GEORGE BARGER. Two years ago a note was published (T., 1916, 109, 568) describing the preparation of 3-phenanthrol-4-aldehyde, first carried out at my suggestion by a former pupil, the late J. W. Smith. As there indicated, I was able to deduce the constitution of the alde hyde from its conversion into 3:4-dihydroxyphenanthrene (morphol). From this, 3: 4-phenanthraquinone was subsequently obtained, and since there has been no opportunity of further experiment in this direction, the preparation of these two compounds is described below. Morphol had not yet been synthesised, and was only known as a degradation product of morphine, for although Pschorr and Simuleanu (Ber., 1900, 33, 1810) prepared its dimethyl ether by Pschorr's well-known general method, they were unable to demethylate this compound without reduction; on boiling with hydriodic acid they only obtained 3-phenanthrol. EXPERIMENTAL. 3:4-Dihydroxyphenanthrene (Morphol). Ortho and para-hydroxyaldehydes may be converted, often quantitatively, into the corresponding diphenols by a reaction due to Dakin (P., 1909, 25, 194; Amer. Chem. J., 1909, 42, 477). In spite of its convenience and wide applicability, this reaction has, strangely enough, received very little attention. Dakin dissolves. the aldehyde in one equivalent of sodium hydroxide and adds a molecular proportion of dilute hydrogen peroxide, when oxidation takes place at once with distinct evolution of heat. On applying the reaction to 3-phenanthrolaldehyde, the sparing solubility of the sodium salt made it necessary to work in very dilute solution, and only a minute quantity of the diphenanthrol was at first obtained. This difficulty was readily overcome by working in pyridine solution and limiting the amount of water as far as possible by the use of highly concentrated potassium hydroxide and hydrogen peroxide, as follows. 3-Phenanthrolaldehyde (1·11 grams) was dissolved in pyridine (10 c.c.) in a flask provided with a dropping funnel and exit tube, and after the air had been displaced by hydrogen, 0'55 c.c. of 30-8 per cent. hydrogen peroxide and then 0·45 c.c. of 12.5 N-potassium hydroxide were added through the tap funnel, which was washed out by a few drops of water. The addition of the potassium hydroxide caused a considerable rise in temperature (but hydrogen peroxide alone, with pyridine, does not react). After boiling for a few seconds, the solution was cooled and excess of hydrochloric acid was added through the funnel. The solution was then extracted with ether, and the ethereal extract washed free from pyridine with acid. On evaporation of the ether, the dihydroxyphenanthrene crystallised; the yield of the crude product was 1:05 grams. It was dissolved in 5 c.c. of boiling benzene, when, on cooling, 0.61 gram separated in almost colourless crystals, and a further 0.22 gram was obtained by adding light petroleum to the mother liquor, the total yield of pure substance thus amounting to 80 per cent. of the theoretical. The substance so obtained was very sensitive to oxidation; it instantly reduced silver nitrate in neutral solution at the ordinary temperature. A trace of ferric chloride gave a reddish-brown coloration, but excess caused oxidation. It was recrystallised from water and from petroleum, b. p. 80-90°, and then melted at 142-143°, so that it seemed to be identical with morphol (O. Fischer and Vongerichten, Ber., 1886, 19, 793, give 143°). By recrystallisation, it was obtained almost, but not quite colourless. A perfectly colourless specimen resulted on sublimation in the vacuum of a Gaede pump at 130°, but the sublimate melted at 142°. On acetylation by boiling with acetic anhydride and a trace of sulphuric acid, an acetyl compound was obtained, which, after crystallisation from petroleum, b. p. 80—90o, and then from methyl alcohol, melted at 158° (O. Fischer and Vongerichten give 159° as the melting point of diacetylmorphol). Since no morphol was available for direct comparison, the diphenol was methylated in order to provide a conclusive proof of its identity, for both the possible dimethyl ethers, 2:3- and 3:4dimethoxyphenanthrene, have been synthesised by Pschorr and his pupils. The crude oxidation product from 1'11 grams of the hydroxyaldehyde was dissolved in 10 c.c. of methyl alcohol and 0.85 c.c. of methyl sulphate (2 molecular proportions), and 0.72 c.c. of 12.5N-potassium hydroxide were added alternately four times. After adding ether, washing with sodium hydroxide, drying, and evaporating the ether, the residue was distilled twice under 12 mm. pressure. At first, crystallisation could not be induced, but a trace crystallised from methyl alcohol on spontaneous evaporation of the solvent, and on adding this to the main bulk, the whole solidified almost completely. The crystals were drained on a tile, the yield was 0.3 gram. When recrystallised from methyl alcohol by evaporation at the ordinary temperature, narrow, rectangular plates were obtained melting at 45°. The picrate formed ruby-red crystals melting at 105-106°, and the dibromo-derivative colourless needles melting at 124-125°. The melting points of 3:4-dimethoxyphenanthrene, its picrate, and its dibromo-derivative are given by Pschorr and Simuleanu (Ber., 1900, 33, 1810) as 44°, 105-106°, and 124-125° respectively, and those of the corresponding 2:3derivatives by Pschorr and Buckow (Ber., 1900, 33, 1829) as 131°, 127-128°, and 160° respectively, so that the diphenol is identified with certainty as 3:4-dihydroxyphenanthrene and the aldehyde, from which it is derived, as 3-phenanthrol-4-aldehyde. 3:4-Phenanthraquinone, CH ̧O2 Having found a comparatively ready method of preparing morphol, I was able to oxidise it to the corresponding quinone by Willstätter and Pfannenstiehl's method (Ber., 1904, 37, 4744). Five grams of silver nitrate were decomposed in a stoppered cylinder with the calculated quantity of sodium hydroxide, and the silver oxide was washed by decantation twelve times with water, six |
