GB757294A - A process for the manufacture of ethylene-glycol ethers of tetrahydrofurfuryl alcohol and compositions containing same - Google Patents

Abstract

Ethers of the general formula <FORM:0757294/IV(a)/1> wherein n is 1, 2, 3 or 4 are prepared by heating tetrahydrofurfuryl alcohol with ethylene oxide in a molar proportion of from 1:1 to 1:4 in the presence of an alkali-metal hydroxide. A preferred hydroxide is sodium hydroxide and this is preferably used in an amount equal to 0.1 to 0.5 per cent by weight of that of the alcohol. The reaction is advantageously conducted at a temperature between 80 DEG and 140 DEG C. in an inert atmosphere, and in a preferred mode of procedure ethylene oxide and nitrogen are introduced into the tetrahydrofurfuryl alcohol and any unreacted ethylene oxide is condensed and reintroduced into the reaction cycle. The reaction product is advantageously isolated by first neutralizing the alkali-metal hydroxide with a non-volatile mineral acid such as phosphoric acid, separating the difficultly-soluble salt so formed and fractionating the crude product remaining. If a small excess of phosphoric acid is used the excess acid may be precipitated by means of barium or calcium carbonate. In examples: (1) tetrahydrofurfuryl alcohol and ethylene oxide in a molar proportion of 1:3 give a mixture of mono-, di- and tri-ethylene glycol ethers of the above general formula; (2) the mono-ether is prepared using a 1:1 molar proportion; (3) the di-ether is prepared using a 1:2 molar proportion. The products are stated to be useful as solvents for pharmaceuticals.ALSO:A pharmaceutical composition contains as a solvent one or more tetrahydrofurfuryl ethers of the general formula; <FORM:0757294/VI/1> wherein n is 1, 2, 3 or 4. A specified active ingredient for such a composition is a mixture of acetyl-choline and pyridyl-3-carbinol, and another drug mixture referred to which may be brought into solution in a similar way is a mixture of the dimethyl-carbanic acid ester of 1-methyl-3-hydroxy-pyridinium bromide with acetyl choline and/or pyridyl-3-carbinol. The ethers are stated to be miscible with water in any proportions and to be good solvents for drugs such as acetylsalicylic acid, ethyl phenyl barbituric acid, alkyl isopropyl barbituric acid, p-amino-salicylic acid and neohesperidin.