Process for the preparation of chalcogene compounds

A process for the preparation of heterocyclic chalcogenone compounds comprising the reaction of an elemental chalcogen selected from the group consisting of elemental sulfur, elemental selenium and elemental tellurium with an ionic liquid or salt having the formula:

• [Cat+][X−],
• wherein:
• [Cat+] represents one or more heterocyclic cationic species of the general formula (1) having adjacent carbon and nitrogen atoms:
• wherein
• Ra represents a C1 to C30 straight chain or branched alkyl group, a C3 to C8 cycloalkyl group, a C6 to C10 aryl group, a C1 to C30 alkaryl group, or a C1 to C30 aralkyl group;
• wherein said alkyl, cycloalkyl, aryl, alkaryl or aralkyl groups are unsubstituted or substituted;
• and
• Q represents a linking moiety, which may be saturated or unsaturated, and which may be substituted or unsubstituted;
• and which when taken together with the adjacent carbon and nitrogen atoms forms a heterocyclic ring comprising 5 to 10 ring atoms;
• and
• [X−] represents one or more anionic species selected from conjugate bases of acids [H+X−] having a pKa value greater than 2.5;
• and
• wherein the reaction is conducted in the absence of an additional base.