GB728524A - Process for the production of hexahydroxybenzene - Google Patents

Abstract

In a process for the production of hexahydroxybenzene carbon monoxide is caused to react at elevated temperature and elevated pressure with an alkali metal other than potassium, preferably sodium and the alkali metal carbonyl thus formed is reacted with an alcohol, water or an acid to produce hexahydroxybenzene by a transposition reaction in which the alkali metal atoms of the carbonyl are exchanged for hydrogen atoms. The alkali metal may contain small amounts of another alkali metal such as lithium or potassium or of an alkaline earth metal such as calcium as an alloy constituent or in the form of a mechanical mixture. The alkali metal may be employed as an amalgam or as a suspension or colloidal solution in a dispersion medium of low volatility. Some carbonate may also be formed. A small amount of a salt of the alkali metal may be added during the reaction. Inert gases such as nitrogen or methane in admixture with the carbon monoxide prevent local overheating. Hexahydrobenzene produced by hydrolysis may be isolated or converted into other products. The product may be oxidized to products of quinoid character such as tetrahydroxyquinone, rhodizonic acid, triquinoyl, croconic acid and leuconic acid or hydrogenated to form inositol. The process may be carried out in a rotary steel autoclave advantageously containing edged grinding bodies. In examples sodium (1) and (4), sodium containing lithium (2), sodium containing potassium (3) are heated in rotary autoclaves with carbon monoxide under pressure to form the hexacarbonyl which is converted to hexahydroxybenzene by the addition of hydrochloric or sulphuric acid, water or ethyl alcohol.ALSO:Alkali metal hexacarbonyls are obtained by a process in which an alkali metal other than potassium, preferably sodium, is reacted at elevated temperature and pressure with carbon dioxide. The alkali metal may contain small amounts of another alkali metal such as lithium or potassium or of an alkaline earth metal such as calcium as an alloy constituent or in the form of a mechanical mixture. The alkali metal may be employed as an amalgam or as a suspension or colloidal soluton in a dispersion medium of low volatility. A small amount of a salt of the alkali metal may be added during the reaction. Inert gases such as nitrogen or methane in admixture with the carbon monoxide prevent local overheating. In examples: Sodium (1) and (4), sodium containing lithium (2) and sodium containing potassium (3) are heated in rotary autoclaves with carbon monoxide under pressure to form the hexacarbonyls. The hexacarbonyls are converted to hexahydroxybenzene (see Group IV (b)).