Process for producing aromatic disulfides

A process for the preparation of an aromatic disulfide represented by the formula (II):

• Yn—Ar—S—S—Ar—Yn (II)
• wherein Ar represents a hydrocarbon aromatic ring group;
• Y represents a monovalent electrophilic group, and when n is 2 or more, a plural number of Y's are the same or different from each other;
• and n is an integer of 1 to 12,
• which comprises carrying out a reaction by reacting:
• (A) an aromatic thioether represented by the formula (I):
• Yn—Ar—S—R (I)
• wherein Y, Ar and n have the same meanings as defined above;
• and R represents a monovalent hydrocarbyl group selected from the group consisting of a monovalent tertiary hydrocarbyl group, a benzyl group and a monovalent secondary hydrocarbyl group derived from a benzyl group;
• with chlorine, in the presence of a catalyst in a catalytic amount of at least one of iodine and hydrogen iodide;
• and in the presence of a halogenated hydrocarbon solvent.

A process for the preparation of an aromatic disulfide represented by the formula (II):

• Yn—Ar—S—S—Ar—Yn (II)
• wherein Ar represents a hydrocarbon aromatic ring group;
• Y represents a monovalent electrophilic group, and when n is 2 or more, a plural number of Y's are the same or different from each other;
• and n is an integer of 1 to 12,
• which comprises carrying out a reaction by reacting:
• (A) an aromatic thioether represented by the formula (I):
• Yn—Ar—S—R (I)
• wherein Y, Ar and n have the same meanings as defined above;
• and R represents a monovalent hydrocarbyl group selected from the group consisting of a monovalent tertiary hydrocarbyl group, a benzyl group and a monovalent secondary hydrocarbyl group derived from a benzyl group;
• with (a) hydrogen chloride and (b) hydrogen peroxide, in the presence of a catalytic amount of at least one of iodine and hydrogen iodide;
• and in the presence of a halogenated hydrocarbon solvent.