GB345517A - A process for preparing cineol-containing oil mixtures - Google Patents

Abstract

Oil mixtures containing 1 : 8-cineol (eucalyptol), together with 1 : 4-cineol and terpene hydrocarbons, are obtained by the action of agents of the type commonly employed in the interconversion of terpene compounds (such as aqueous solutions of sulphuric acid, phosphoric acid, hydroxylated acids, sulphonic acids or bisulphates) on compounds of the same molecular formula as cineol or of a molecular formula differing from that of cineol by the addition of the elements of one or more molecules of water (e.g. terpin hydrate, terpin, terpineol, terpinenol), or on terpene hydrocarbons (such as pinene or sabinene) which on treatment with dilute acids are converted into initial materials of the above type, at temperatures below 80 DEG C., with immediate removal of the reaction product from the sphere of action. The temperature is kept lower, the higher the concentration of the acid or other agent employed. The removal of the product may be carried out by vacuum distillation or by extraction with indifferent solvents such as chloroform or toluene. In examples : (1) terpineol is treated with 30-40 per cent sulphuric or phosphoric acid at about 35 DEG C., the product, consisting of 22 per cent each of 1 ; 8- and 1 : 4-cineol and 45 per cent of hydrocarbons (limonene, terpinolene, a -, b - and d -terpinene), being continuously removed by vacuum distillation; (2) terpin is treated with 60 per cent sulphuric acid at -10 DEG C., and the product, of the same composition as in (1), is extracted by a stream of toluene, the extract being fractionally distilled. Specification 317,757, [Class 2 (iii), Dyes &c.], is referred to.