REGIOSELECTIVITY OF THE TELLURIUM-INDUCED CYCLISATION OF TERMINALLY SUBSTITUTED ALLYL, BUTENYL AND PROPARGYL THIOETHERS OF THIENOPYRIMIDINE

The method of electrophilic intramolecular cyclization is widely used for the synthesis condensed thienopyrimidine derivatives. In this work, regioselectivity process terminally substituted allylic derivatives, but-1-enyl and propargyl thioethers with p-methoxyphenyltellurttrichloride was investigated.
 It established that as a result tellurium-induced butenyl 5,6-dimethyl-3-phenylthieno[2,3-d]pyrimidin-4(3H)-one p-methoxyphenyltellurium trichloride, angular tricyclic chlorides ― 8-(dichloro(4-methoxyphenyl)-tellanyl)-2,3,9-trimethyl-4-oxo-5-phenyl-5,7,8,9-tetrahydro-4H-thieno[3',2':5,6]pyrimido[2,1-b][1,3]thiazine-10-ium 9-((dichloro(4-methoxyphenyl)-tellanyl)methyl)-2,3-dimethyl-4-oxo-5-phenyl-5,7,8,9-tetrahydro-4H-thieno­[3',2':5,6]pyrimido[2,1-b][1,3]thiazine-10-ium an annealed six-membered ring in form complexes trichloride. proved 5,6-dimethyl-2-(prop-2-yn-1-ylthio)-3-phenylthieno[2,3-d]pyrimidin-4(3H)-one aryltellurium trichloride occurs formation complex chloride 8-((dichloro(4-methoxyphenyl)-tallanyl)methylidene)-2,3-dimethyl-4-oxo-5-phenyl-4,5,7,8-tetrahydrothiazolo[3,2-a]thieno [3,2-e]pyrimidin-9-ium one geometric isomer.
 Keywords: heterocyclization; trichloride; organotellurium compounds; 4H-thieno[3',2':5,6]pyrimido[2,1-b][1,3]thiazine-10-ium; thiazolo[3,2-a]thieno[3,2-e]pyrimidin-9-ium.