From Other Te-Organo Tellurocarboxylates

Refluxing tellurophthalide in benzene with 2,4-bis[4 -methoxyphenyl]-2,4-dithioxo-l, 3,2,4-dithiaphosphetane (Lawesson s reagent) produced dark green crystals of 1-thiono-l, 3-dihydrobenzo-2-tellurophene, a surprisingly stable compound. 

Te-Aryl arenetellurocarboxylates decompose at temperatures above 165 with loss of tellurium. They do not react with 4-nitrophenylhydrazine. Phenylhydrazine cleaves the benzoyl groups with concomitant formation of diaryl ditelluriums.  

Irradiation of benzene solutions of 7e-aryl arenetellurocarboxylates with light from a mercury lamp generated radicals via homolytic cleavage of the Te—CO bond. The free radicals subsequently formed aldehydes, diorgano tellurium compounds, and diorgano ditellurium compounds via hydrogen abstraction, dimerization and elimination of tellurium, or dimerization -. The products of the photo-induced reaction of Te-4-methylphenyl 2-methylthiobenzene(tellurocarboxylate) are given as an example .  

Attempts to form palladium complexes with 7e-aryl arenetellurocarboxylates led to cleavage of the Te — CO bond.  

Tellurophthalide in benzene solution was hardly affected by irradiation with 300 nm light, with phenyl magnesium bromide diphenyl ditellurium was formed. Methyl iodide removed tellurium from the heterocycle yielding trimethyl telluronium iodide.  

---