GB479253A - Manufacture of dialkoxy substituted glycols - Google Patents

Abstract

Dialkoxy substituted glycols are prepared by condensing an alkoxyaldehyde to produce a dialkoxy substituted oxy-oxo-compound and converting the condensation product into the glycol by hydrogenation. The condensation is preferably conducted in the anhydrous state, in the cold, and with an alkaline condensing agent, preferably an alcoholate of the alcohol forming the alkoxy group. The hydrogenation is effected in the liquid phase with the aid of a catalyst such as a nickel skeleton catalyst prepared by dissolving out with alkali the aluminium or silicon from an alloy of either of these substances with nickel. In an example, 7 c.c. of a 10 per cent solution of sodium methylate in methanol are dropped slowly and with stirring into 306 gms. of 3-methoxybutyraldehyde at - 5 DEG C.; the condensation product produced, viz. 2 : 6-dimethoxy-3-formyl-4-oxyheptane, is acidified with acetic acid, diluted with methanol, and treated with hydrogen at 40 DEG C. in the presence of 20 per cent of a nickel skeleton catalyst to produce 2 : 6-dimethoxy-3-oxymethyl - 4 - oxyheptane. 3 - Ethoxy - butyraldehyde or a mixture of alkoxy-aldehydes may be similarly treated. The products and their esters and ethers are useful as solvents for lacquers, especially cellulose ester lacquers, paints, perfumes, or cleansing agents.ALSO:Hydrogenation catalysts are prepared by dissolving out with alkali lye the aluminium or silicon from alloys of either of these substances with nickel.