Patent GB-190300705-A (GB)
Title: Improved Process for the Preparation of Hydrolised Pseudoionone and its Homologues and for their Transformation into Cyclic Ketones.
Filed: 1903-01-10
Granted: 1903-11-12
Abstract: 705. Lake, H. H., [Chuit Naef & Co.]. Jan. 10. Pseudo-ionones.-Consists in hydrolysing pseudoionone and its homologues by adding to them, drop by drop, concentrated acids, such as sulphuric or phosphoric acids, the whole being well cooled and constantly stirred. After standing, the mixture is thrown upon ice and water, and then washed with water, and afterwards with sodiumcarbonate solution. A little benzene is preferably used in washing, and afterwards removed along with other volatile products, by means of a current of steam. The final product is dried and distilled in vacuo, if a pure product is desired. The hydrolysed pseudo-ionone distils at 176‹-178‹ C. (not corrected) under 9 mm. pressure, has a density of 0À960 at 15‹ C., and does not distil with steam as ionone and pseudo-ionone do. The methyl homologue boils at 186‹-192‹ C. (n.c.) under 12 mm. pressure, and has a density of 0À950 at 20‹ C., when prepared from methylpseudo-ionone of density 0À896 at 20‹ C., which is obtained by condensing citral and methyethylketone with sodium ethylate, sodium peroxide, or sodiumamide. When a light caustic-soda solution is used as the condensing-agent, the methyl-pseudo-ionone, containing a mixture of other bodies, has a density of 0À912 at 20‹, and yields a hydrolysed product of density 0À956 at 20‹, which boils at about, 190‹ C. at 13À5 mm. pressure. The ethyl homologue, resulting from a pseudo-ionone of density 0À913 at 20‹ which is obtained by condensing citral and methylpropylketone with caustic soda, has a density of 0À950 at 20‹ C., and boils between 198‹- 205‹ at 17À5 mm. pressure. alpha- and #-Ionones.-The above hydrolysed products are converted into the corresponding cyclic alpha- and #-ionones, containing one molecule of water less, and nearly free from hydrocarbides and resins, by pouring them into an excess of concentrated sulphuric, phosphoric, or formic acid, the whole being well cooled and constantly stirred. The mixture is heated to 20‹-30‹ C. after standing for some time (although, when formic acid is used, no heating is required), and then poured over ice and water. The oil which results is washed with water and then with sodium carbonate, and finally distilled in steam, or in vacuo. Phosphoric and formic acids chiefly yield the alpha-product, and sulphuric acid the #-product. The densities and boiling-points of the various products are :-alphaionone 0À935 at 20‹ C ; #-ionone 0À940 at 20‹ C. ; alpha-methylionone 0À931-0À932 at 20‹ C., b.p. 138‹- 143‹ (n.c) at 14 mm. pressure, #-methylionone 0À939-0À941, b.p. 143‹-150‹ (n.c.) at 15 mm. pressure, these being derived from the hydrolysed product of density 0À950 at 20‹ C. Those derived from the product of density 0À956 at 20‹ have the following properties :-density alpha-0À933-0À936, #- 0À939-0À943, at 20‹ C. ; b.p. alpha-134‹-138 C. (n.c.) at 13 mm. and #-132‹-140‹ C. (n.c.) at 11 mm. pressure. The ethyl homologue, obtained by using phosphoric acid, has a density 0À931 at 20‹ C. and a b p. 149‹-160‹ C. at 16 mm. pressure, while, when sulphuric acid is used, the density of the resulting mixture of compounds is 0À956 at 20‹ C. and the b.n. 145‹-169‹ C. at 16 mm. pressure. The foregoing hydrolysed pseudo-ionones and ionones yield semi-carbazones, and the ionones yield pbromophenylhydrazones.