A compound represented by a formula [1D] as shown below (wherein R.sup.1A, R.sup.1B, R.sup.2A, R.sup.2B, R.sup.3A and R.sup.3B represent a hydrogen atom, an optionally substituted C.sub.1-6 alkyl group, and the like) is useful as an intermediate for producing a thionucleoside, and the production method of the present invention is useful as a method for producing a thionucleoside.

##STR00001##

A compound represented by a formula [1D] as shown below (wherein R.sup.1A, R.sup.1B, R.sup.2A, R.sup.2B, R.sup.3A and R.sup.3B represent a hydrogen atom, an optionally substituted C.sub.1-6 alkyl group, and the like) is useful as an intermediate for producing a thionucleoside, and the production method of the present invention is useful as a method for producing a thionucleoside.

##STR00001##

A method for producing halogenated carbonates is provided, the method having the steps of reacting a halogenated hydroxyl moiety with an alkyl formate in the presence of a liquid solvent and a solid base. An exemplary halogenated carbonate so produced is trifluoroethyl methyl carbonate.

A method for producing halogenated carbonates is provided, the method having the steps of reacting a halogenated hydroxyl moiety with an alkyl formate in the presence of a liquid solvent and a solid base. An exemplary halogenated carbonate so produced is trifluoroethyl methyl carbonate.

A diaryl carbonate containing a compound of the following formula (I) in an amount of less than 1,000 ppm by mass, and a method for producing the same:

##STR00001##

wherein R.sup.1 represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, or an aryloxy group.

A diaryl carbonate containing a compound of the following formula (I) in an amount of less than 1,000 ppm by mass, and a method for producing the same:

##STR00001##

wherein R.sup.1 represents a hydrogen atom, a halogen atom, an alkyl group, an alkoxy group, an aryl group, or an aryloxy group.

A compound represented by a formula [1D] as shown below (wherein R.sup.1A, R.sup.1B, R.sup.2A, R.sup.2B, R.sup.3A and R.sup.3B represent a hydrogen atom, an optionally substituted C.sub.1-6 alkyl group, and the like) is useful as an intermediate for producing a thionucleoside, and the production method of the present invention is useful as a method for producing a thionucleoside. ##STR00001##

A compound represented by a formula [1D] as shown below (wherein R.sup.1A, R.sup.1B, R.sup.2A, R.sup.2B, R.sup.3A and R.sup.3B represent a hydrogen atom, an optionally substituted C.sub.1-6 alkyl group, and the like) is useful as an intermediate for producing a thionucleoside, and the production method of the present invention is useful as a method for producing a thionucleoside. ##STR00001##

A compound represented by a formula [1D] as shown below (wherein R.sup.1A, R.sup.1B, R.sup.2A, R.sup.2B, R.sup.3A and R.sup.3B represent a hydrogen atom, an optionally substituted C.sub.1-6 alkyl group, and the like) is useful as an intermediate for producing a thionucleoside, and the production method of the present invention is useful as a method for producing a thionucleoside. ##STR00001##

The invention relates to a process wherein a dialkyl carbonate stream containing an ether alkanol impurity is subjected to extractive distillation using an extraction solvent to obtain a top stream comprising dialkyl carbonate and a bottom stream comprising the ether alkanol impurity and the extraction solvent, wherein the extraction solvent is an organic compound containing one or more ester moieties and/or ether moieties which organic compound does not contain a hydroxyl group. Further, the invention relates to a process for making a diaryl carbonate, comprising reacting an aryl alcohol with a stream containing a dialkyl carbonate from which stream an ether alkanol impurity has been removed in accordance with the above-described process.