Vas'kevych R. Synthesis of condenced and functional derivatives of thieno[2,3-d]pyrimidine

пиримидины. 3. The heterocyclization of thieno[2,3-d]pyrimidi- ne derivatives under action of some electrophylic and nucleophylic reagents was studied. It has been found that cyclization direction and thus the structure of the heterocycle formed is governed by the nature of reagents. The rearrangemment of trihydrothiazinothienopyri- midine into dihydrothiazolothienopyrimidines, which runs when heated in ethanol-DMSO solutions, was established. New reaction route for heterocyclization of thieno- pyrimidines, which bears thiosemicarbazide- fragments at 2 - site under action of alkyl halides was found. The reaction leads to triazolothienopyrimidine. The reaction of Potassium salts of 2-thiothieno- [2,3-d]pyrimidin-4(3H)-one with ethyl 4-bromo- crotonate and ethyl 4-chloroacetоacetate, and chemical properties of the products formed were studied.