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##

Method for preparation of 5-alkylsalicylaldoximes with formula 1, where R is a C6-C16 alkyl group, consisting in that into a water-alcohol solvent system, p-alkylphenol, sodium hydroxide, chloroform and hydroxylamine are introduced, while in relation to the alkylphenol used, sodium hydroxide and chloroform are used in amounts from the stoichiometric amount to a 100% excess, and hydroxylamine is used in amounts from the stoichiometric amount to a 60% excess, and the reaction is carried out at a temperature of 60-75? C. for 1.5-4 h, and then, at a temperature of 20-30? C., the post-reaction mixture is acidified till the pH of the aqueous phase <7.0 is obtained, and next, an alcohol-water azeotrope is distilled off with an admixture of unreacted chloroform, the residue is mixed with a neutral C5-C10 hydrocarbon solvent, the layers are separated, and the solvent is distilled off from the organic phase.

Method for preparation of 5-alkylsalicylaldoximes with formula 1, where R is a C6-C16 alkyl group, consisting in that into a water-alcohol solvent system, p-alkylphenol, sodium hydroxide, chloroform and hydroxylamine are introduced, while in relation to the alkylphenol used, sodium hydroxide and chloroform are used in amounts from the stoichiometric amount to a 100% excess, and hydroxylamine is used in amounts from the stoichiometric amount to a 60% excess, and the reaction is carried out at a temperature of 60-75? C. for 1.5-4 h, and then, at a temperature of 20-30? C., the post-reaction mixture is acidified till the pH of the aqueous phase <7.0 is obtained, and next, an alcohol-water azeotrope is distilled off with an admixture of unreacted chloroform, the residue is mixed with a neutral C5-C10 hydrocarbon solvent, the layers are separated, and the solvent is distilled off from the organic phase.

Method for preparation of 5-alkylsalicylaldoximes with formula 1, where R is a C6-C16 alkyl group, consisting in that into a water-alcohol solvent system, p-alkylphenol, sodium hydroxide, chloroform and hydroxylamine are introduced, while in relation to the alkylphenol used, sodium hydroxide and chloroform are used in amounts from the stoichiometric amount to a 100% excess, and hydroxylamine is used in amounts from the stoichiometric amount to a 60% excess, and the reaction is carried out at a temperature of 60-75? C. for 1.5-4 h, and then, at a temperature of 20-30? C., the post-reaction mixture is acidified till the pH of the aqueous phase <7.0 is obtained, and next, an alcohol-water azeotrope is distilled off with an admixture of unreacted chloroform, the residue is mixed with a neutral C5-C10 hydrocarbon solvent, the layers are separated, and the solvent is distilled off from the organic phase.

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##

Method for preparation of 5-alkylsalicylaldoximes with formula 1, where R is a C6-C16 alkyl group, consisting in that into a water-alcohol solvent system, p-alkylphenol, sodium hydroxide, chloroform and hydroxylamine are introduced, while in relation to the alkylphenol used, sodium hydroxide and chloroform are used in amounts from the stoichiometric amount to a 100% excess, and hydroxylamine is used in amounts from the stoichiometric amount to a 60% excess, and the reaction is carried out at a temperature of 60-75? C. for 1.5-4 h, and then, at a temperature of 20-30? C., the post-reaction mixture is acidified till the pH of the aqueous phase <7.0 is obtained, and next, an alcohol-water azeotrope is distilled off with an admixture of unreacted chloroform, the residue is mixed with a neutral C5-C10 hydrocarbon solvent, the layers are separated, and the solvent is distilled off from the organic phase.

Method for preparation of 5-alkylsalicylaldoximes with formula 1, where R is a C6-C16 alkyl group, consisting in that into a water-alcohol solvent system, p-alkylphenol, sodium hydroxide, chloroform and hydroxylamine are introduced, while in relation to the alkylphenol used, sodium hydroxide and chloroform are used in amounts from the stoichiometric amount to a 100% excess, and hydroxylamine is used in amounts from the stoichiometric amount to a 60% excess, and the reaction is carried out at a temperature of 60-75? C. for 1.5-4 h, and then, at a temperature of 20-30? C., the post-reaction mixture is acidified till the pH of the aqueous phase <7.0 is obtained, and next, an alcohol-water azeotrope is distilled off with an admixture of unreacted chloroform, the residue is mixed with a neutral C5-C10 hydrocarbon solvent, the layers are separated, and the solvent is distilled off from the organic phase.

Method for preparation of 5-alkylsalicylaldoximes with formula 1, where R is a C6-C16 alkyl group, consisting in that into a water-alcohol solvent system, p-alkylphenol, sodium hydroxide, chloroform and hydroxylamine are introduced, while in relation to the alkylphenol used, sodium hydroxide and chloroform are used in amounts from the stoichiometric amount to a 100% excess, and hydroxylamine is used in amounts from the stoichiometric amount to a 60% excess, and the reaction is carried out at a temperature of 60-75? C. for 1.5-4 h, and then, at a temperature of 20-30? C., the post-reaction mixture is acidified till the pH of the aqueous phase <7.0 is obtained, and next, an alcohol-water azeotrope is distilled off with an admixture of unreacted chloroform, the residue is mixed with a neutral C5-C10 hydrocarbon solvent, the layers are separated, and the solvent is distilled off from the organic phase.