Process for preparing 1,4-dioxan-2-ones

DETAILED DESCRIPTION OF THE INVENTION The process provided by this invention is founded upon the discovery that, in the presence of a catalytic amount of hydrogen fluoride, carbon monoxide, formaldehyde, and a 1,2-glycol react to prepare a 1,4-dioxan-2-one.
The reaction is carried out under moderate conditions of temperature and pressure.
The reaction to form a 1,4-dioxan-2-one is believed to proceed according to the reaction sequence: ##STR2## wherein R is selected from the group consisting of hydrogen; and C.
sub.
1 to C.
sub.
20 alkyl, cycloalkyl, hydroxyaldyl, aralkyl and alkoxyalkyl.
Glycols wherein R is C.
sub.
1 to C.
sub.
20 alkyl are preferred for use herein.
The reaction is carried out using known processing techniques.
Accordingly, the product of step 1, a 4-substituted-1,3-dioxolane, can be contacted directly with carbon monoxide to prepare the final 1,4-dioxan-2-one product.
The 1,2-glycol used in the process is a common diol prepared by a variety of methods.
For example, unsaturated compounds can be oxidized by dilute aqueous permanganate and hydrogen peroxide in the presence of osmium tetroxide: ##STR3## In another method, 1,2-epoxides can be hydrolyzed to 1,2-glycol by either acid or base catalysts.
In yet another method, 1,2-dihalides are converted to 1,2-glycols by formation of an intermediate biacetate which is hydrolyzed to the corresponding glycol: ##STR4## wherein X is a halogen, e.
g.
, Cl.
Representative 1,2-glycols suitable for use in the process of this invention include, for example, ethylene glycol; 1,2-propanediol; 1,2-butanediol; 3-trifluoromethyl-1,2-pentanediol; 5-phenyl-1,2-pentanediol; 3-methoxy propane-1,2-diol; 4-(p-nitrophenyl)-1,2-butanediol; 2-cyclohexyl-1,2-ethanediol; 1,2-octanediol; glycerol and the like.
The reaction is carried out at a temperature of from about 0.
degree.
C to about 100.
degree.
C, preferably from about 20.
degree.
C to about 60.
degree.
C; and a carbon monoxide partial pressure of from about 10 psia to about 4000 psia, preferably from about 10 psia to about 3000 psia