GB787406A - Process for the manufacture of trimethylene oxide compounds containing hydroxyl groups - Google Patents

Abstract

Trimethylene oxide methylols having the formula <FORM:0787406/IV (b)/1> where R represents a methyl, ethyl or hydroxymethyl group are produced by reacting a polyhydroxyl compound of the formula R-C(CH2OH)3, where R is as above-defined, with a carbonic acid derivative of the general formula O=C(X)2, wherein X is a halogen atom or an alkoxy, cycloalkoxy, aryloxy or tetrahydrofurfuryloxy radical or X-X is a divalent dioxy-substituted alkylene, cycloalkylene or arylene radical, the hydroxy compounds corresponding to said radicals having a boiling point of at most 160 DEG C. at 0.1 mm. Hg., followed by eliminating carbon dioxide from the resulting product. Suitable carbonic acid derivatives are phosgene, the methyl, ethyl, butyl, amyl, hexyl, heptyl 2-ethyl-hexyl, cyclopentyl, cyclohexyl, phenyl, cresyl or tetrahydrofurfuryl esters of chlorocarbonic acid, and the corresponding dimethyl, diethyl, and so on, diesters of carbonic acid, and the carbonates of ethylene glycol, 1,2-butanediol, 1,3-butanediol, 1,2-cyclohexanediol and pyrocatechol. In the first stage of the conversion, the polyhydroxyl compound is reacted with phosgene at - 10 DEG C. to +100 DEG C., with a chlorocarbonic acid ester at - 10 DEG C. to +160 DEG C., or with a carbonic acid diester at temperatures between 90 DEG and 160 DEG C., with the removal of 2 mols. of HX to form a 5-hydroxymethyl-2-m-dioxanone. This step may be effected at normal or reduced pressure. When using phosgene it is preferred to dissolve the polyhydric alcohol in a solvent and to remove the liberated hydrogen chloride by blowing air through the mixture or by boiling out. When using chlorocarbonic esters, the addition of at least the stoichiometric amount of a tertiary amine, e.g. pyridine, N,N-dimethyl aniline or triethyl amine, is preferred. When using carbonic acid diesters, an inorganic basic compound, such as an alkali metal hydroxide, carbonate or alcoholate may be added. The splitting off of carbon dioxide is generally effected at temperatures of above 120 DEG C. and may also be expedited by adding the aforesaid basic compounds. The product is advantageously distilled off as it is formed, under reduced pressure if desired. The products are useful as solvents and as intermediates in the manufacture of plasticizers and plastics. In examples, 3-ethyl-3-methylol-trimethylene oxide is obtained from 1,1,1-trimethylol propane with (1) phosgene in dioxane; (3) gaseous phosgene; (4) diethyl carbonate and potassium carbonate; (5) di-n-butylcarbonate and sodium butanolate; (6) di-(2-ethylhexyl) carbonate and sodium; (7) dicyclohexyl carbonate and sodium cyclohexanolate; (8) diphenyl carbonate and sodium phenolate; (9) ethylene glycol carbonate; (11) pyrocatechol carbonate and sodium; (12) butanediol - 1,3 - carbonate (obtained by re-esterifying butane-1,3-diol with diethyl carbonate in the presence of potassium carbonate below 120 DEG C.,); (13) ethyl chlorocarbonate and N,N-dimethylaniline; or (15) phenyl chlorocarbonate and pyridine; 3-methyl - 3 - methylol - trimethylene oxide is obtained from 1,1,1-trimethylol-ethane with (2) phosgene in dioxane; or (14) methyl chlorocarbonate in pyridine; 3,3-dimethylol-trimethylene oxide is obtained from pentaerythritol with (10) diethyl carbonate and potassium carbonate; or (16) ethyl chlorocarbonate and pyridine, minor amounts of 2,6-dioxa-4-spiroheptane also being formed.