GB688207A - Improvements in and relating to organic hydroxy compounds - Google Patents

Abstract

A process for the production of aldol condensation products comprises bringing an aliphatic carbonyl compound into contact in the liquid phase at a temperature not in excess of 30 DEG C. with a catalyst comprising calcium oxide or calcium hydroxide supported on a lithia-alumina complex prepared by heating a mixture of g -alumina or a form of alumina which yields g -alumina on heating and lithia or a lithium compound decomposable to lithia on heating to a temperature in excess of 600 DEG C., the g -alumina referred to being obtained by precipitation, e.g. of the species boehmite or hydrargillite from soluble aluminium compounds, e.g. by alkali and calcination at 400 DEG to 600 DEG C. Starting materials mentioned are methyl ethyl, methyl propyl and methyl isopropyl ketones which yield respectively 3 - methylheptan - 3 - ol - 5 - one and 3,4 - dimethylhexan - 3 - ol - 5 - one; 4-methylnonan - 4 - ol - 6 - one and 4 - methyl-5 - ethylheptan - 4 - ol - 6 - one and 2,3,6-trimethylheptan - 3 - ol - 5 - one and 2,3,4,4-tetramethylhexan - 3 - ol - 5 - one. The liquid carbonyl compound may be passed through one or more beds of catalyst in a temperature controlled reactor and the process may be operated batchwise or continuously. The lithia-alumina complex may be prepared by impregnating the g -alumina with a solution of a lithium salt decomposable to lithia on heating and igniting the product at a temperature in excess of 600 DEG C. The catalyst may be prepared by washing the lithia-alumina complex, crushing the granules and impregnating the latter with a soluble calcium compound capable of thermal decomposition to the oxide and heating the impregnated granules to yield the oxide. Typically, nitric acid washed g -alumina is ignited and after soaking in lithium nitrate solution is again ignited. The product is washed, steeped in molten calcium nitrate and heated to decompose the nitrate. The catalysts may be reactivated by calcining and largely restored by further damping and heating. In an example acetone is passed over catalysts both fresh and reactivated, prepared as described above and converted to diacetone alcohol.ALSO:A catalyst comprises calcium oxide or calcium hydroxide supported on a lithiaalumina complex prepared by heating to a temperature above 600 DEG C a mixture of g -alumina or a form of alumina which yields g -alumina on heating and lithia or a lithium compound decomposable to lithia on heating. The g -alumina referred to is obtained by precipitation, bechmite or hydrargillite from soluble aluminium compounds e.g. by alkali and calcination thereof at 400 DEG to 600 DEG C. In the preparation of a typical catalyst nitric acid washed g -alumina is ignited and after soaking in lithium nitrate solution is again ignited at 950 DEG C. The product is washed, steeped in molten calcium nitrate and heated to decompose the nitrate. The catalysts may be reactivated by calcining and largely restored by further damping and heating. The catalysts may be employed in the production of aldol condensation products by bringing an aliphatic carbonyl compound in contact therein in its liquid phase at temperature, not in excess of 30 DEG C, [see Group IV(b)]